Australian Tea Tree Industry Insights

I spoke with Tony Larkman, CEO of the Australian Tea Tree Industry Association, about the nonprofit he heads, his own introduction to essential oils, and issues facing the essential oils industry and tea tree oil in particular.

Tony Larkman, ATTIA CEO

Tony Larkman, ATTIA CEO

Tony Larkman was born and raised in Kenya. After travelling extensively through Africa, Europe and the Middle East he returned to East Africa in 1986 to work first as a purchasing officer and then as a pig farmer before moving to Australia in 1992. Over the next 17 years Tony turned his hand to feed milling and grain trading before becoming an IT Manager and then a Purchasing Manager. In 2009 he started working for ATTIA Ltd where he realized that he had finally stumbled on the answer to a question that had plagued him since he was child: “What do you want to be when you grow up?” Tony is now the CEO of ATTIA Ltd which is probably the most organized and active industry body for any single essential oil.

RT: Your introduction to tea tree oil was as a pig farmer?
TL: It was the mid-1980s, and a spray bottle of ‘healing oil’ with tea tree oil as the active ingredient was hung near the door of every building on the piggery. We used it everywhere and for everything, for both workers and animals – from minor cuts and scratches through to cleaning and preparing wounds for stitching after fights between boars – some of which were horrendous and likely to have been fatal without the magic of the healing oil. It also helped mask some of the smell of a piggery, which was a bonus.

What is ATTIA, and what services does it provide?
The Australian Tea Tree Industry Association (ATTIA Ltd) is an Australian based not-for-profit organization formed in 1986 as the peak body to promote and represent the interests of the Australian tea tree industry. From the grower/producer to the manufacturer of off-the-shelf products for public use, ATTIA supports and promotes the responsible use of pure Australian tea tree oil (TTO). ATTIA’s aim is to develop a stable, cohesive, environmentally friendly, and internationally competitive TTO industry producing quality assured TTO that meets or exceeds international standards. ATTIA promotes the safe effective use of TTO for a wide range of applications. More information about ATTIA here.

Full membership of ATTIA is open to all Australian tea tree industry participants while associate membership is open to international participants in the supply chain. Our services include:

  • Support and advocacy in dealing with government and regulatory agencies, research and development groups and the media.
  • Leadership and representation in the formulation of overall industry strategy.
  • Generic industry promotion at national and international levels.
  • The collection and compilation of market data to inform all links in the supply chain of factors influencing supply and demand for pure Australian TTO.

Australian Tea Tree Industry Association

Is the ATTIA website useful for consumers, enthusiasts or practitioners?
ATTIA’s website was created to cater to all levels of interest from school children preparing a project through casual consumers and passionate enthusiasts to professionals. The most commonly accessed pages which are easily navigated to by using the drop-down boxes in the navigation pane at the top of every page are:

Home Page A summary of who ATTIA is and where pure Australian tea tree oil comes from.
About Tea Tree A more in-depth look at production, uses, safety and efficacy.
FAQ Answers 20 of the most commonly asked questions on tea tree oil.

For professionals and researchers there is also a regularly updated, searchable Literature Database where detail on more than 1,200 papers can be accessed. These include most articles published on the safety, efficacy and uses of pure tea tree oil since 1904 when the species from which pure tea tree oil is distilled (Melaleuca alternifolia) was first described by Maiden & Betche.

Australian Tea Tree harvest

Harvesting tea tree. Picture courtesy of Mark Webb

How much tea tree oil is produced annually in Australia and around the world and to where is it distributed?
We know that between 400 and 500 metric tons of pure Australian TTO is produced annually; this is dependent on the weather and growing conditions from year to year. 80% of this is exported, most to North America. In 2012 a total of 409 metric tons of Australian TTO was exported to the following destinations:

  • 50.27% North America (USA, Canada, Mexico)
  • 25.66% Europe (Continental Europe, UK, Russia)
  • 22.76% Asia (India, Middle East, South East Asia, China, Japan)
  • 0.98% Africa (South Africa, Egypt)
  • 0.33% South America (Brazil, Chile, Colombia)

Tea tree oil is also produced in several other countries including China, South Africa, Kenya, Indonesia and Thailand. All of this TTO is produced from Melaleuca alternifolia, an Australian native tree that originated in the coastal regions of Southern Queensland and Northern NSW. No one can accurately state how much TTO is produced in these other countries.

Are there different qualities of tea tree oil?
Let me clarify first that there is no ‘pharmaceutical grade’ of TTO, nor is there a ‘therapeutic grade’. These are purely marketing inventions intended to convince a buyer that a particular brand is in some way superior to that of competitors. The main ingredient and most active bacteriostat in TTO is terpinen-4-ol which, according to the current standard, must be between 30% and 48% in TTO. Almost all pure Australian TTO is traded today with 40%+ terpinen-4-ol. The only way to make sure you are getting the best available TTO is to ask the retailer or manufacturer if they are using pure Australian TTO and how they verify this. If they can’t (or won’t) answer then either they are cheating or they genuinely don’t know. If the latter is true please refer them to the ATTIA website or Facebook page.

The second great marketing myth that has been roundly debunked in scientific literature is the belief that the level of another compound invariably found in pure Australian TTO: 1,8-cineole, needs to be as low as possible to prevent irritation. Today’s standard allows up to 15% of 1,8-cineole (which is actually the main constituent of another Australian native essential oil – eucalyptus oil – which contains around 80% of 1,8-cineole, or eucalyptol as it is also known) and there is clear evidence  that it makes no difference in TTO at levels of up to 8%.

Pure Australian Tea Tree Oil

The ATTIA Code of Practice seal

Tea tree oil is steam distilled from the leaves and terminal branches of the Australian native tree Melaleuca alternifolia. When correctly distilled, stored and shipped any oil extracted from M. alternifolia is just as safe and efficacious whether it is produced in Australia or anywhere else in the world. In Australia all production, distillation, storage and shipment processes are stringently controlled through the ATTIA Code of Practice (COP) quality assurance program to guarantee that only pure, natural TTO derived from M. alternifolia is supplied in perfect condition to discerning manufacturers both locally and around the world. In other countries issues related to pesticide use, identification of source plants, poor distillation, as well as poor handling and storage practices can contaminate or degrade the oil to the point where it is no longer safe to use and cannot even be described as tea tree oil.

                                “TTO has an enviable reputation for its

                                antibacterial, antifungal, anti-inflammatory,

                                anticancer and antiviral properties”

In addition to these quality assurance issues, as TTO passes up the supply chain, some unscrupulous suppliers and traders deliberately contaminate it with byproducts that are derived either from other essential oils such as pine oil or from synthetic production processes. This adulteration can significantly compromise the safety and efficacy of the product when used as a replacement for pure TTO. In some instances I believe this practice has led to TTO being abandoned as a traditional herbal product because either ‘it doesn’t work’ or ‘it causes irritation’. The most frustrating part of this for ATTIA is that the claims made by those who sell the adulterated material are based in the main on ATTIA sponsored science into the safety, efficacy and uses of pure Australian TTO. More information on adulteration is available from a Facebook site, which was created specifically to raise awareness of adulteration in TTO.

These days pure Australian TTO is traded in commercial quantities using the International Standards Organization’s standard ISO 4730:2004 but the oil typically has 40% or more terpinen-4-ol, and a maximum of 3-4% 1,8-cineole, depending on the buyer. Occasionally you can still see “T39-C2”,”T39-C4” or “T40-C4” on some bottles; all they are doing is trying to differentiate their product from that of their competitors. The fact remains that there is clear scientific evidence that pure TTO is just as safe and effective regardless of the levels of terpinen-4-ol or 1,8-cineole as long as it conforms to ISO 4730:2004 standards. More information on the ISO standard for pure Australian TTO can be found here.

Tea tree quality standards

Tea tree quality standards

What are the principal issues that impact tea tree oil and essential oil quality?
I have already touched on adulteration as a major issue and I believe this is the most significant quality threat we currently face as an industry. However, even pure TTO can be degraded over time due to poor distillation, storage and handling so producers, traders, manufacturers and end users need to be aware of these factors and minimize their effect. Exposure to light, high temperatures and atmospheric oxygen all lead to degradation of some of the components of TTO which can increase the incidence of skin irritation and sensitization.

On the ATTIA website in the section about packaging you can find a paper on the stability of pure Australian TTO which can also be downloaded here. This details the science behind storage and handling procedures. A quick summary:

  • ATTIA recommends that pure Australian TTO sold to the public should only be stored in small (up to 100 ml) dark glass bottles at temperatures not exceeding 25oC with a use by date of 2 years from the date of manufacture in unopened bottles.
  • Once opened these bottles should be stored in cool, dark conditions with the cap tightly sealed and discarded after 6 months if still unused.
  • For bulk storage, the ATTIA Code of Practice requires producers to use only stainless steel storage and transport vessels and to store the oil in cool, dark conditions with minimum exposure to air.
  • ATTIA recommends 3 years from filling as the use-by date for pure Australian TTO sold in correctly filled, purged (Nitrogen or Argon) and tightly sealed stainless steel drums stored at an ambient temperature not exceeding 25oC.

What do you see as the outstanding benefits of tea tree oil?
TTO has an enviable reputation for its antibacterial, antifungal, anti-inflammatory, anticancer and antiviral properties, which are all well supported scientifically. In 2013, TTO was exported from Australia to 43 countries, where its uses include cosmetic, industrial, and medicinal applications. It is interesting occasionally to see that in advertising for some new or emerging essential oils, comparison is most often made to the efficacy and safety of Australian TTO – reinforcing its position as a global leader.

Australian TTO is a natural product that contains more than 113 compounds and I believe that it is the synergistic effect of these compounds that makes it a true healing oil. Some components like terpinen-4-ol (the major constituent of TTO) have proven antimicrobial and antifungal properties on their own but there are all the other components which must assist and complement the terpinen-4-ol with factors such as skin penetration, bactericidal, fungicidal and anti-inflammatory activity.

Another outstanding benefit is its proven ability to control commonly occurring bacteria such as MRSA and VRSA that are rapidly becoming totally resistant to all conventional antibiotics, particularly in hospital environments where management of these infections is proving such a challenge to healthcare professionals. I believe that as we run out of control options, more and more health professionals will turn to products like TTO that have not only proven antimicrobial activity but also possess a natural complexity that makes development of bacterial or fungal resistance extremely unlikely.

Flowering Tea Tree copy

Melaleuca alternifolia in flower

What current or upcoming research projects is ATTIA involved in?
Over the last 20 years the Australian tea tree industry has been fortunate to enjoy a close partnership with the Australian Government’s Rural Industries Research and Development Corporation (RIRDC). RIRDC has co-funded much of the research, development and extension work done to develop our industry through a tree breeding program, agronomy advances, development of distillation techniques and safe storage and handling procedures for pure Australian TTO. In addition to these basic but vital tools RIRDC has co-funded much of the University based research into the safety, efficacy and uses of TTO resulting in more than 50 publications which are available for download from the TTO page on the RIRDC website here.

Currently ATTIA is developing a test for adulterated oil which we hope to have adopted by internationally recognized standards organizations in the near future. Called the Chiral Purity Test, this measures the ratios of the optical isomers of three compounds that occur in pure Australian TTO: terpinen-4-ol, α-terpineol and limonene. Each one of these compounds occurs in two forms, with specific ratios in TTO. Since we know what these ratios should be, any variation is a strong indicator that the product has been contaminated. Table 1 below illustrates 57 samples of Australian TTO sourced directly from plantations over five years (2007 – 2011) showing a consistent ratio (70:30) of the two terpinen-4-ol enantiomers (dextro and levo). Table 2 shows 47 samples of commercially available TTO sourced from around the globe as well as a sample of 98% pure terpinen-4-ol. Some have a significant deviation from the expected ratio for pure TTO, indicating adulteration. This demonstrates how easy it is to identify real TTO from adulterated material. As well as synthetic terpinen-4-ol, potential contaminants include industrial waste from ‘normalising’ pine, eucalyptus and other essential oils. ATTIA intends to use the test to “out” any offenders by reporting them to the relevant regulatory bodies in their jurisdictions.

Chiral Ratios for Terpinen-4-ol

Table 1

Terpinen-4-ol enantiomeric %

Table 2

ATTIA is also keenly following the progress of researchers at the University of Western Australia (UWA) who are investigating the anti-cancer potential of pure Australian TTO. A few years ago topical application of a very specific formulation containing pure Australian TTO as the active ingredient was shown to significantly reduce the viability of melanoma and mesothelioma cancer cells in vitro and since then studies of skin cancers in mice have confirmed its ability to reduce or resolve some types of skin cancers. Researchers believe this may be due to the stimulatory effect TTO has on the body’s own immune system. Much work remains to be done before this reaches proof-of-concept stage.

Researchers at UWA are also investigating the clinical activity of formulated products containing TTO for activity against acne-causing bacteria. This will eventually result in a pilot study using volunteers to measure the activity of the most promising formulations in a human population.

For the grower members of ATTIA there is continuing support for research into high yielding genotypes of M alternifolia through both a conventional breeding program and using cutting-edge technology to identify specific gene markers for high yield and disease resistance that occur in natural populations. These markers can be used to quickly and efficiently identify individuals with outstanding properties from existing wild populations for infusion into the ongoing conventional breeding program to increase genetic diversity and ensure sustainability. In an emerging area ATTIA and the Australian Government have recently commenced a joint study to investigate the use of biochar generated from spent leaf and inter-crop legume planting to reduce both carbon and nitrous oxide emissions. Increasing productivity and developing a low emission industry not only ensures survival of an industry that utilizes a native crop plant in a sustainable way but also improves the green credentials of an already clean and green industry.

Tea tree oil safety issues that have been raised in the past include skin sensitization, endocrine disruption and bacterial resistance. What is your take on these?
I want to address these separately as all three are critically important questions and need different answers.

Allergic reactions and skin sensitization
TTO that has been well stored since distillation is a safe, natural product and its efficacy and safety is well known and documented. There is absolutely no doubt that some people are allergic to pure Australian TTO in the same way that some people are allergic to peanuts, milk or wheat. This can manifest itself in many forms from reddening, irritation and itching of the skin through to blisters and burns. Whenever and wherever TTO is used for the first time a user should make sure that it is diluted in a carrier oil (eg jojoba) to 10% before trying a small drop on the soft skin of the inside of the forearm. Wait 24 hours, unless immediate signs of itching or swelling are noticed. If a reaction occurs, immediately wash the area with soap and water and discontinue use. It is worth mentioning that slight, transient irritation is sometimes seen in clinical trials, this may be considered acceptable, depending on the benefits. However, allergic reactions are never acceptable.

Immediate, strong allergic reactions to TTO are uncommon and have been estimated to occur in less than 0.5% of the population. Sensitization to TTO has also been well documented; this occurs where repeated exposure to a product increases the reaction to its application. This can happen with pure TTO, but it is more likely to occur where TTO has either been poorly stored, which increases the level of peroxides and other irritants through oxidation, or when the oil has been adulterated.

Endocrine disruption
This is a myth and is the one that get me the most upset. I often see reference in scientific articles, blogs and online comments that refer to a link between gynecomastia (man boobs) and lavender and tea tree oils and I have been battling the negative publicity that erupted when the original work by Henley et al was first published in the NEJM in 2007. The authors linked the use of personal care products containing lavender and/or tea tree oil to breast development in 3 prepubertal boys and then went on to “demonstrate” that the endocrine disruption was caused by the two essential oils using well trays in the laboratory. These 96 well trays, made of plastic, contain phthalates which are known endocrine disruptors and I know from personal experience that TTO is an excellent solvent and extracts phthalates from any unprotected plastic it comes in contact with very quickly and efficiently. I believe this is why Henley et al reported the estrogenic and anti-androgenic “activity” of TTO and lavender possibly without even realizing the truth. More here.

RT-pub-lavender-2If you look at this another way, at least 400,000 kg of pure Australian TTO is shipped annually and used by thousands of people in hundreds (or even thousands) of products as well as being applied as an undiluted oil for medical, cosmetic and aromatherapy uses every day. If TTO did indeed have any kind of estrogenic or other endocrine disruptive activity then surely gynecomastia or at least some other symptoms would have been seen in more than the three boys Henley et al looked at.

Bacterial resistance
The suggestion that exposure to sub-lethal levels of TTO induced resistance in bacteria was first reported in 2007 and again in 2008 by McMahon et al. In 2008, and again in subsequent years, researchers at the UWA TTO research group tried to replicate the work done by McMahon et al to no avail. Repeated attempts by scientists at the University of Western Australia (Hammer et al 2008, Hammer et al 2012, Thomsen et al 2013) failed to induce resistance to any antibiotics in any of the bacteria studied and led them to conclude in 2013 that “…there is no evidence to suggest that tea tree oil induces resistance to antimicrobial agents.” Unlike most antibiotics, which are usually single molecules, TTO contains more than 113 naturally-occurring molecules. The synergistic effect of these compounds makes it improbable that bacteria could develop resistance to TTO.

Do you feel that current legislation impacting tea tree oil is reasonable, and do you anticipate more restrictive legislation?
We live in a world where regulation plays a major part in the registration and use of any cosmetic or medicinal ingredient whether natural or synthetic in origin. Regulations are there to protect users from harm. Some products and chemicals are very harmful if used incorrectly or indiscriminately so we all have to accept that regulation is a fact of life; ATTIA’s approach is and always will be cooperative. Having said that it is worth pointing out that legislation varies far too much around the world and I would prefer a more uniform approach to this in the same way that many countries are now adopting and moving towards the UN’s Globally Harmonized System of Classification and Labeling of Chemicals (GHS). This makes legislation far easier to manage.

Restrictive legislation is frustrating to any essential oil industry simply because most of it is designed to work with a single molecule which is clear-cut, easy to identify and assay, and is usually also patentable. An essential oil is a variable complex of molecules that, like the human genome, belongs to all of us and at the same time to none of us – in other words a regulator’s nightmare! However there is also no doubt that these oils are efficacious, safe and widely used around the world in cosmetic and medicinal formulations so I believe that regulators need to look closely at these naturally occurring substances and create separate legislation for them. This is beginning to occur in some places, but while these are being developed essential oil industries are being forced to address two separate sets of legislation, which can be burdensome.

What are the principal challenges facing the tea tree oil industry?
In the short to medium term adulteration of a pure, natural product with byproducts and other waste from chemical factories is the foremost challenge facing our industry today. This practice is motivated purely by profit and relies totally on the safety, efficacy and reputation of pure Australian TTO while undercutting the market price often to the point where a farmer cannot safely and sustainably produce the original product. The result of this cheating is to devalue TTO as a viable product. Unless it is combated vigorously, this could lead to adulterated or wholly synthetic concoctions becoming the norm for customers buying or trading ‘tea tree oil’ resulting in a devalued and virtually useless substitute for the real thing. ATTIA is currently cooperating with scientists and regulators from around the world to develop a cheap, effective test that will allow a discerning manufacturer to detect some of the more common forms of adulteration. Once this has been adopted by internationally accepted Standards organizations such as ISO and BP it will make it harder and far more expensive for those who adulterate pure TTO to continue to dupe manufacturers and end-users for their own gain.

Young plantation_ GD copy

A young tea tree plantation

In the longer term, regulation is the other major challenge. Any natural substance varies slightly from year to year and from region to region but there are recognized standards in place that  manage this so why can’t regulators also deal with the natural variation in these substances more sympathetically? On top of this there is also the prohibitive cost of developing data required in some jurisdictions to enable registration as a medicine or cosmetic ingredient. This can run into millions of dollars which cannot be recouped over the period a patent is usually granted for a conventional single molecule pharmaceutical because no patent is available for TTO. Traditional or customary use patterns covering many decades by bona fide practitioners should be acceptable evidence of the safety and efficacy of natural products such as TTO.

How does ATTIA help support the tea tree oil industry?
As an industry association, ATTIA provides both a forum and a vehicle for members (and non-members where necessary) to promote and act on emerging trends and regulatory, market or other pressures and trends in a timely and cohesive manner. By maintaining a monitoring watch on these factors ATTIA has been well placed to prepare and submit dossiers to regulatory bodies that include the USA, Canada and Europe. These submissions are prepared to ensure that pure Australian TTO can continue to be used in these jurisdictions both as a cosmetic ingredient and as a traditional herbal remedy for its wide range of clinically supported uses.

ATTIA also provides advice, training and auditing services in the critical area of quality assurance or QA. This promotion of ATTIA’s voluntary Code of Practice helps ensure that all pure Australian TTO offered into both international and local markets is always in perfect condition with documented QA practices that can be seamlessly incorporated into a manufacturer’s own QA procedures.

Since its inception ATTIA has also invested considerable time, effort and funding on research into the production, distillation, storage safety, efficacy and uses of pure Australian TTO. Much of this work, supported by ATTIA member donations and Australian Government Research and Development Grants, has been done at the University of Western Australia where the TTO Research Group has published more than 50 papers in their primary areas of research which are the antimicrobial and anticancer properties of TTO. Many of these articles are used to support claims and as proof of concept for the safety, efficacy and uses of pure Australian TTO. More on UWA here.

Estrogens in Plastic Labware

The safety of essential oils in puberty, and hormonal effects in general, are important health concerns. In a 2007 research report by Colorado and North Carolina doctors and scientists, in vitro evidence seemed to support the notion that lavender oil and tea tree oil were responsible for breast growth in three young boys, suggesting an estrogenic action. Although this article has subsequently been cited more than 180 times in scientific literature and is still widely quoted on medical websites, lavender oil has been exonerated and there is still no evidence of any link between the in vitro findings and the three cases. Now evidence is emerging that suggests the lab test results may have been due to estrogenic compounds in the plastic laboratory ware used.

In vitro: In an artificial environment, such as a test tube
In vivo: Occurring or carried out in the living organism

Plastic 96-well plate

Essential oils can leach estrogenic compounds from plastic trays like this 96-well plate.

In an April 2013 article the estrogenic claim is again made: “Other examples of naturally occurring endocrine disruptors include lavender oil, tea tree oil and fennel, all of which have been linked to breast development in prepubertal children presumably due to estrogenic effects.” (Note that ‘fennel’ refers to fennel tea, not the essential oil.) Christine Carson, Tony Larkman and myself wrote a letter contesting this assertion, and this is being published in the journal in March 2014. The important points of our letter are:

• Tea tree and lavender oils are now widely described as having estrogen-promoting properties.

• The research on which this assertion is based only demonstrated an in vitro effect.

• The plastic trays used in the in vitro testing contain estrogenic compounds such as phthalates.

• Essential oils are known to leach these compounds out of plastic.

• Therefore, the in vitro results could have been due to contamination.

• There is no other reason to believe that tea tree oil or lavender oil is estrogenic, and no estrogenic constituents of either oil has ever been identified.

• In vivo testing revealed no estrogenic action in lavender oil.

• No causal link was ever established between either of the essential oils and the three cases of prepubertal breast development cited by Henley et al.


Christine Carson is a microbiologist at the University of Western Australia

In our letter, Christine proposes that the in vitro results may be due to the essential oils leaching estrogenic chemicals, such as phthalates, out of the plastic containers used in the laboratory testing. Exactly this type of contamination of MCF-7 tests (such as those used by Henley et al 2007) has been demonstrated in plastic labware from 7 different manufacturers (Ishikawa et al 2001). This idea finds further support in a recent publication, which reported that frankincense oil began to dissolve plastic laboratory trays at concentrations of 50, 25 and 12.5% (Al-Kharousi et al 2013).

The idea that essential oils can affect the structural integrity of some plastics, beginning to break down, or dissolve them, is not controversial. Neither is the idea that plastic laboratory vessels can sometimes contaminate sensitive biological assays. Research from the University of Alberta describes how plastic laboratory products may be a likely source of error in many assays (McDonald et al 2008). The failure to appreciate the solvent properties of essential oils, combined with the use of plastic laboratory vessels, may have led to estrogenic activity being mistakenly ascribed to lavender oil and tea tree oil.

Only one other supporting study has been published (Nielsen 2008). The same type of laboratory plastic trays were used as in the Henley et al study (96-well plates), and the estrogenic action of tea tree oil was similar in both.

It is always unwise to assume that an effect seen from in vitro testing will also apply to the living body. There are many possible reasons for this, but the idea that the laboratory equipment itself might be affecting results is unusual.

Al-Kharousi ZS, Nzeako B, Mothershaw AS 2013 Initial observation on the interaction of frankincense oil with selected plastics. International Journal of Food Properties doi: 10.1080/10942912.2012.698442

Carson CF, Tisserand R, Larkman T 2014 Lack of evidence that essential oils affect puberty. Reproductive Toxicology In press

Fisher MM, Eugster EA 2013 What is in our environment that affects puberty? Reproductive Toxicology doi: 10.1016/j.reprotox.2013.03.012

Ishikawa T, Takano K, Fujita T et al 2001 Estrogenic impurites in labware. Nature Biotechnology 19:812

McDonald GR, Hudson AL, Dunn SM et al 2008 Bioactive contaminants leach from disposable laboratory plasticware. Science 322:917

Henley DV, Lipson N, Korach KS et al 2007 Prepubertal gynecomastia linked to lavender and tea tree oils. New England Journal of Medicine 356:479-85

Nielsen JB, 2008 What you see may not always be what you get – bioavailability and extrapolation from in vitro tests. Toxicology In Vitro 22:1038–1042

Politano VT, McGinty D, Lewis EM et al 2013 Uterotrophic assay of percutaneous lavender oil in immature female rats. International Journal of Toxicology doi: 10.1177/1091581812472209


Is there such a thing as re-distilled peppermint oil?

Hello Mr. Tisserand,

I am curious about re-distilled peppermint.
Someone wrote me recently and said that there was no such thing as a re-distilled peppermint. I’d like to know if this is true.

Thank you!

Close-up of Mentha piperitaA few essential oils are ‘rectified’. Because this is also described as “re-distilled” it has given rise to the myth that many essential oils are distilled more than once – 1st, 2nd and 3rd grades, or distillations. But, once plant material has been distilled, it contains no essential oil – it is never re-distilled.

Rectification involves fractional distillation in order to remove unwanted constituents. The essential oil is put through a second process using a tall, narrow column. In the case of bitter almond oil, hydrocyanic acid (cyanide) is removed, as it is highly toxic. In peppermint, minor sulfur constituents are removed as they impart a slightly unpleasant taste, and most peppermint oils are used in food flavoring.

Two essential oils – camphor and ylang-ylang – undergo a separation process during distillation, so there are five grades of yang-ylang oil (extra, I, II, III and complete), and four colors of camphor oil (white, blue, yellow, brown)! But none of this involves re-distillation.

So yes, there is such a thing as re-distilled peppermint, but it’s the oil that’s re-processed, not the plant. Strictly speaking it is less natural, as something that was naturally there has been removed. In the case of bitter almond oil, no-one is complaining.


Essential Oils, Stroke Patients, and Bergamot

brain image

Dear Mr. Tisserand,

I have been a student of essential oils for the last 15 years or so. I have what seems to be a defeating question. I’ve looked for the answer from some people in aromatherapy and tried also to find the answer online.
Is there any kind of research on essential oils and healing the brain, whether it be strokes or epilepsy?
I am particularly interested in essential oils on healing stroke victims.
I am not in the medical field. I would like to do a research paper on this but have hit a dead end.
My husband had a stroke 6 years ago. I asked a very knowledgeable aromatherapist what
oils would heal a stroke. He said there were none.
I asked my brother who has been in the medical field for 20 years, what can heal the brain from a stroke. He said there is nothing.
I do not accept these answers. I am a firm believer that the human body has the power to heal anything. If essential oils can pass the blood/brain barrier, why wouldn’t there be an essential oil that could heal the brain? For every ailment, there is a plant.
I did do a little experiment after my husband’s stroke. It was about a week after it happened and he went into rehabilitation. The first night I used bergamot essential oil and put a few drops on his pillow before he went to sleep. The next morning the nurses were bragging how alert he was that day trying to get up and walk. That night, I put a couple of drops of lavender on his pillow before he went to sleep. The nurses the next day said he was awful. They said he wouldn’t try to get up. He wouldn’t try to eat. That night I used bergamot again. The next day the nurses said he was up, more alert, using a walker to try and gain strength back. After that night, I continued to use bergamot until he got out for that hospital.
I would really appreciate any information you can give me. Thank you so much for your time.

Lynn W.

Hi Lynn,

Thank you for your detailed message, and I applaud your efforts to help your husband.

As far as I know, there is no clinical research that shows a benefit for stroke victims from essential oils. However, there is good clinical research showing that inhalation of an essential oil constituent (perillyl alcohol) has been successful in treating brain cancer in some patients. This, and other research, demonstrates that the molecules of inhaled essential oils do enter the brain, and that this route has potential for healing in some neurological diseases.

In one rat study, bergamot essential oil inhibited the damage caused by “focal ischemia” (the same type of damage caused by stroke) . The oil was injected, not inhaled. This suggests that bergamot might be helpful if used at about the same time as a stroke occurred, but it does not necessarily suggest a curative effect after the fact. However, if anything is likely to be helpful, bergamot would be a good candidate, and your own observations support this conclusion.

Best wishes,

Tea tree oil quality and constituents

I am writing this in response to a recent discussion on various facebook pages about tea tree oil (TTO), and whether a TTO with 51% terpinen-4-ol would be better than one with 41%, or whether 51% suggested adultration. Most TTO is produced in Australia and China, and this article is about the quality of Australian TTO, since the Chinese oils generally do not conform to the Australian standards, and there is no quality standard for Chinese TTO. The major constituent of TTO is terpinen-4-ol (T-4-ol). Most essential oils contain a single major constituent, and yet the main point of natural medicine is that we don’t isolate “active ingredients” and use them instead of the whole natural product.

Harvesting tea tree in Port Macquarie, courtesy of The Australian Tea Tree Industry Association

Harvesting tea tree in Port Macquarie, courtesy of ATTIA

Once we do that, we call it a drug. And, once we do that there is no longer any possibility for synergistic action. Synergy is the interplay, or interaction between constituents of plant-based medicines, that often give them effects that cannot be obtained by using a single, isolated substance. The action of TTO owes a great deal to its content of T-4-ol, and there may be instances when T-4-ol alone is more effective. But there are certainly situations in which the whole oil is more effective. So the question here is this: What is the ideal amount of T-4-ol, and is more always better?

There is an industry standard for TTO, and the most recent version was published in 2004. Standards for essential oils are set by the International Organization for Standardization (ISO). The actual ISO standard is copyrighted and is not in the public domain, but for the purposes of this discussion all we need to know is that the standard for T-4-ol in TTO is 30-48%. This means that any genuine, natural, unadulterated TTO should contain a minimum of 30% and a maximum of 48% T-4-ol. (For anyone who wants to better understand the way a standard can help identify if TTO is genuine there is a document on the ATTIA (Australian Tea Tree Industry Association) website: How ISO & AS Standards help identify fraudulent material.) I asked Tony Larkman, spokesperson for ATTIA, whether a TTO with more than 48% T-4-ol was a good thing or a bad thing. This is his response:

They put a ceiling on the T-4-ol to stop the bush cutters (who were distilling wild harvested material in wood fired pot stills) from cheating – it is easy to use the wrong source plant material “by mistake”; back then it was all done by smelling the product and paying cash based on the buyers skill at detecting the cheats followed by CG analysis when they got back to base some weeks later. One sample had 47% so they made the standard inclusive at 48%. The 30% minimum was put there to stop them cheating the other way by diluting with some of the eucalyptus and other oils (including turpentine form the hardware store!).

I spoke to the technician from the Australian Government’s Department of Primary Industry (DPI) essential oil testing facility at Wollongbar, NSW last week asking him what the highest level of T-4-ol he had ever seen in his 15+ years experience as an analytical chemist in a sample of pure Australian TTO. His response: Under a proper distillation regime 42% T-4-ol result is very high and rarely does one see 43% T-4-ol. It is extremely rare to see 45%. I once had a 47% T-4-ol result only to find after a double check from another sample from the same batch that it was a fault in the calibration of the GC unit.

Distillation, June 2012, courtesy of ATTIA

Distillation, June 2012, courtesy of The Australian Tea Tree Industry Association

I have never seen a T-4-ol  level in pure TTO to exceed 45%, neither has the analyst from the DPI. When I see the T-4-ol level over 42% I immediately submit it for a chiral test on the assumption that it has been adulterated with T-4-ol which is a waste product from factories that ‘correct’ eucalyptus, sandalwood, tarragon, pine, fennel and aniseed oils. It is also found in turpentine. I would personally like to see the max level dropped to 45%.

It is a myth that higher levels of T-4-ol make TTO more effective. All studies on the efficacy, safety and usage of pure Australian TTO have been conducted using a T-4-ol content of about 40–42%, the level at which it most commonly occurs in plantation sourced oils which have been bred to yield at this level. Australian TTO is a complex mixture of 113+ compounds and it is the synergistic effect of all of these compounds that makes TTO such an effective antibacterial, antifungal and anti-inflammatory product.

Since the mid 1980s there have been many discussions about the optimal levels of T-4-ol and 1,8-cineole in TTO. The fact is that increasing T-4-ol levels above 40% makes no difference to the safety and most importantly the efficacy of Australian TTO. The current demand for T-4-ol levels at around 40% ensures that a sustainable quality of pure, natural TTO can be made available. Demanding T-4-ol levels in excess of 42% will in no way increase the efficacy and safety of TTO; in fact it increases the likelihood of being supplied with an adulterated product contaminated with industrial waste and by-products from other industries where there is no quality assurance, likely resulting in contamination with unknown and untested substances.

I know that some people don’t like standards for natural products, but I believe standardization is a mostly good thing, and certainly for TTO we can see the benefits of ‘fingerprinting” as the analysis and comparison process is sometimes known. I will be publishing a lengthy interview with Tony Larkman in the coming weeks.

Lemon on the rocks: keep your essential oils cool

Essential oils are happiest when cold.

If you keep them refrigerated they will last twice as long, especially if you live in a warm climate. Essential oils are expensive, so you want them to stay active as long as possible!


Cold good, oxidation bad
With time, most essential oil constituents oxidize, and heat promotes oxidation. Once oxidation starts it’s difficult to stop, though it is a very slow process – it takes months. So if you accidentally leave your oils in a hot car for a few hours, don’t worry – they will still be fine. And, changing temperature either way does not bother them, so long as they are cool most of the time.

Citrus fruit oils are high in limonene, and limonene is especially prone to oxidation. As it oxidizes, the percentage of pure limonene in your lemon oil decreases significantly, because it is being oxidized into other substances. There are two consequences of this:

* Because your lemon oil no longer contains as much limonene, it no longer does what it’s supposed to do! As the limonene oxidizes, the therapeutic potential of the oil decreases.

* The chemicals formed – mostly oxides and peroxides of limonene – are not very pleasant, not very therapeutic, and they increase the risk of skin sensitization from the lemon oil. The risk is still small, but it’s no longer negligible.

The limonene content of lemon oil decreased from 67.1% to 30.7% in 12 months when the oil was stored at 77°F (25°C) with the cap removed for three minutes every day. However storage at 41°F 5°C, with the cap removed for three minutes only once a month, resulted in minimal degradation (Sawamura et al 2004). When lemongrass oil was intentionally oxidized, it lost almost all of its antibacterial activity (Orafidiya 1993) .

Courtesy of Stillpoint Aromatics

Courtesy of Stillpoint Aromatics

The ideal temperature
35-38 degrees, the temperature of most refrigerators, is great for essential oils. If you fancy keeping them in your freezer that’s OK too, but the additional cooling won’t bring much added benefit. A couple of things to watch out for:

* If you put essential oil bottles into a fridge with food, some of that food may start to taste of essential oil. So keep them in a container: wooden box, plastic box or zip-up bag (see pic below). If you have a large collection of oils, or plan to, buy a dedicated fridge – they come in all sizes.

* Essential oils become progressively more viscous as they cool. This won’t noticeably affect most oils, but some may be slow to pour, and rose otto will go solid. (If it’s undiluted rose otto and it doesn’t go solid in your fridge, then it’s not a genuine otto.) If you do need to slightly warm up an essential oil, hold the bottle in your hand for a minute. But most will be fine.

How to tell if an essential oil has oxidized
* It will not smell as fresh as it did. You may not notice, as the change is very slow, but when you buy a new oil you may see the difference.

* Citrus oils sometimes go cloudy. Watch out for this. If it happens, let the sediment settle to the bottom of the bottle. This will take several hours.  Then use a clean pipette to transfer the good oil into another bottle, and toss the one with the sediment.

Don’t rely on tester oils in stores as a guide to what a fresh oil should smell like. These testers are constantly being opened and exposed to the air, so many of them are probably well on the road to being oxidized. (But, the oils for sale are still good, because they are sealed!)

Courtesy of Jenni Davenport

How long will my essential oils keep?
It depends when you start the clock. If you time it from the moment of distillation, you have to know when that was, and most of the time we don’t know that. And, an essential oil in a full, unused bottle will stay fresh for a long time. So – start the clock when you first open the bottle, and use the following guideline for essential oils that are refrigerated:

Citrus fruit, neroli, lemongrass, frankincense, tea tree, pine and spruce oils
1-2 years

Virtually every other essential oil
2-3 years

Sandalwood, vetiver, patchouli
4-8 years

For non-refrigerated oils, halve these numbers, especially in warm climates. Keep it simple: keep them in a fridge! If you haven’t kept your essential oils refrigerated up to now, it’s not too late to start.

Some other tips
Use your deceased oils in household cleaning products, especially citrus fruit oils. Or trash them.

  • For long-term storage, undiluted essential oils should be kept in colored glass containers.
  • Keep bottles capped when not using.
  • Essential oils are inflammable – never leave naked flame burners unattended.
  • Always keep essential oils where small children cannot get to them. Accidents have occurred from toddlers ingesting essential oils.

Orafidiya LO 1993 The effect of autoxidation of lemongrass oil on its antibacterial activity. Phytotherapy Research 7:269-271

Sawamura M, Son U-S, Choi H-S et al 2004 Compositional changes in commercial lemon essential oil for aromatherapy. The International Journal of Aromatherapy 14:27-36

Climate Change News 2013: Essential Oils Cool Planet

It now appears that the world would have warmed more than it has were it not for the aromatic cocktail of chemicals emitted by plants. It turns out that this can change the weather – and anything that changes the weather day after day and year after year changes the climate too. While this mechanism is nowhere near strong enough to save us from global warming, it may have been stronger in the past when the air was cleaner. So could it be that Gaia is not powerless after all? Stephen Battersby

It has long been suspected that the envelope of essential oil vapor around an aromatic plant helps protect it from extremes of temperature, especially heat. It makes sense that higher temps lead to greater essential oil evaporation, and this in turn has a cooling effect on the plant (evaporation from a surface is always cooling). Until recently, no one imagined that there might be a cooling phenomenon taking place on a much larger scale.

There is always invisible water in the ambient air. There are also tiny particles floating in the air, such as salt and dust; these are called aerosols. The water vapor and aerosols are constantly bumping into each other. When the air is cooled, some of the water vapor sticks to the aerosols when they collide – this is condensation. Eventually, bigger water droplets form around the aerosol particles, and these clump together with other droplets, forming clouds.

The Gaia hypothesis
The Gaia hypothesis is James Lovelock’s idea that the planet as a whole is capable of environmental self-regulation (Lovelock & Margulis 1974). In 1987, Lovelock and others proposed a feedback mechanism that could counterbalance global warming involving the oceans. Called the CLAW (after its authors) hypothesis, this proposed that algae in the sea emit a gas called dimethyl sulfoxide, which can react with air to form sulfuric acid vapor and condense into aerosols (Charleson et al 1987). Warmer weather causes greater algal growth, and the aerosols could feasibly cool the planet by reflecting sun directly, and also indirectly by making clouds whiter. However, water droplets do not form and grow unless they are at least 100 nanometers in size, and models of the CLAW hypothesis later showed that particles would not reach even close to this size. In addition not enough dimethyl sulfoxide is released to make a difference.

In 2004, scientists at the University of Helsinki proposed an alternative model involving pine trees instead of algae (Kulmala et al 2004). They hypothesized that increased temperatures and atmospheric CO2 would lead to increased photosynthesis and forest growth, leading to an increase in pine oil emissions. Pine oil is mostly composed of monoterpenes such as limonene and pinene. These terpenes rise above the trees, and combine with sulphur dioxide and other aerosols to form especially large cloud droplets. Clouds with larger droplets are whiter, reflecting more sunlight back into space, cooling the land below, and thus counteracting the effects of global warming. (More trees also means more CO2 absorption, so there is a double benefit.) Even if forest growth did not increase, in warmer weather, pine trees emit significantly more essential oil (Fuentes et al 2000).

Global warming offset
This hypothesis now looks like a reality – not so much in terms of increased forest growth, but warmer temperatures do result in greater pine oil emissions, which do cause whiter and larger clouds. A research team at Manchester University has demonstrated that, as aerosols and water accumulate, the presence of terpenes changes the chemistry of the drops, allowing them to attract more water, and this can substantially increase the  number of droplets (Topping et al 2013). A cloud with a greater concentration of droplets is a whiter, fluffier cloud.

The clincher comes from a study involving 11 weather stations around the planet. A team including Markku Kulmala and Paul Paasonen, also at Helsinki, sampled the air at these stations, counting the number of aerosols of 100 nanometeres or larger, and also the level of terpenes. They found a clear pattern (Paasonen et al 2013). The effect is strongest in places such as eastern Siberia and Finland, where the air is clean. “But in more polluted areas, the feedback is not significant” says Paasonen.

The extent of the effect is not known, but it may not be very big. It could offset global warming by as much as 10%, or it might be less than 1%. And, where there is significant atmospheric pollution, pine oil evaporation makes no difference. But it’s one reason to preserve existing pine forests, and also applies to spruce, larch and similar species. Russia, Scandinavia and Canada take note. In theory, it will also apply to any large plantation of aromatic plants, but in reality pine forests may be the only significant contributor because of their mass.

The terpenes are only able to contribute to cloud formation because, once in the atmosphere, they are oxidized by ozone and other gases into slightly larger particles, and this is an important step in the process. So more ozone could also lead to whiter, larger clouds, again supporting the Gaia hypothesis. This is somewhat ironic because high ozone at ground level also oxidizes these terpenes, which of course come from essential oils too, and inhaling the resulting oxidation products can cause respiratory problems. So what is good for the planet above tree level is not so good for people with respiratory problems below. Fortunately, this only happens where there are high ozone levels.

Battersby S 2013 Call in the Clouds. New Scientist issue 2923: 32-35

Charlson RJ, Lovelock JE, Andreae MO, Warren G 1987 Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate. Nature 326 (6114): 655–661 doi:10.1038/326655a0

Fuentes JD, Lerdau M, Atkinson R et al 2000 Biogenic hydrocarbons in the atmospheric boundary layer: a review. Bulletin of the American Meteorological Society 81: 1537-1575

Kulmala M, Suni T, Lehtinen KR et al 2004 A new feedback mechanism linking forests, aerosols, and climate. Atmospheric Chemistry & Physics 4: 557-562

Lovelock JE, Margulis, L 1974 Atmospheric homeostasis by and for the biosphere: the Gaia hypothesis. Tellus Series A 26: 2–10

Paasonen P, Asmi A, Petaja T et al 2013 Warming-induced increase in aerosol number concentration likely to moderate climate change. Nature Geoscience 6: 438-442

Topping D, Connolly P, McFiggans G 2013 Cloud droplet number enhanced by co-condensation of organic vapours. Nature Geoscience 6: 443-446

Sniffing Rosemary Can Increase Memory By 75%

Published 8-April-2013 by Jenny Hope at

Rosemary herb

Useful and attractive: Research has found the essential oil from rosemary helps long-term memory and alertness

Why a whiff of rosemary DOES help you remember: Sniffing the herb can increase memory by 75%

• The Tudors believed rosemary had powers to enhance memory
• In Hamlet, Ophelia says ‘There’s rosemary that’s for remembrance’
• Researchers have found the oil helps alertness and arithmetic

Shakespeare was right in saying rosemary can improve your memory.

Researchers have found for the first time that essential oil from the herb when sniffed in advance enables people to remember to do things.

It could help patients take their medication on time, it is claimed, or even help the forgetful to post a birthday card.

In a series of tests rosemary essential oil from the herb increased the chances of remembering to do things in the future, by 60-75 per cent compared with people who had not been exposed to the oil.

Other studies have shown the oil increases alertness and enhances long-term memory.

Rosemary has been long been linked to memory, with the most famous literary reference found in Hamlet when Ophelia declares: ‘There’s rosemary, that’s for remembrance: pray, love, remember.’ It is used in modern-day herbal medicine as a mild painkiller and for migraines and digestive problems.

A team of psychologists at Northumbria University, Newcastle, tested the effects of essential oils from rosemary.

Dr Mark Moss, who will present the findings today at the British Psychology Society conference in Harrogate, said the benefit of aromas was becoming clear through scientific investigation.

He said ‘We wanted to build on our previous research that indicated rosemary aroma improved long-term memory and mental arithmetic.

‘In this study we focused on prospective memory, which involves the ability to remember events that will occur in the future and to remember to complete tasks at particular times. This is critical for everyday functioning, for example when someone needs to remember to post a birthday card or to take medication at a particular time.’

Rosemary essential oil was diffused in to a testing room by placing four drops on an aroma stream fan diffuser and switching this on five minutes before people entered the room.

Altogether 66 people took part in the study and were randomly allocated to either the rosemary-scented room or another room with no scent.

In each room participants completed a test designed to assess their prospective memory functions.

Herb lore: William Shakespeare referred to rosemary’s power to enhance the memory in Ophelia¿s line in Hamlet

This included tasks such as hiding objects and asking participants to find them at the end of the test and instructing them to pass a specified object to the researcher at a particular time.

All the tasks had to be done with no prompting but if the task was not performed then different degrees of prompting were used.

The more prompting that was used the lower the score.

The volunteers, all healthy adults, also completed questionnaires assessing their mood.

Blood was taken from volunteers and analysed to see if performance levels and changes in mood following exposure to the rosemary aroma were related to concentrations of a compound known as 1,8-cineole present in the blood.

The compound is also found in the essential oil of rosemary and has previously been shown to act on the biochemical systems that underpin memory.

The results showed that participants in the rosemary-scented room performed better on the prospective memory tasks than the participants in the room with no scent.

This was the case for remembering events, remembering to complete tasks at particular times, and the speed of recall.

The results from the blood analysis found that significantly greater amounts of 1,8-cineole were present in the plasma of those in the rosemary scented room, suggesting that sniffing the aroma led to higher concentrations.

Rosemary is also used as a painkiller and for migraines and digestion

Power of herbs: Rosemary is also used as a painkiller and for migraines and digestion

Previous research suggests volatile molecules from essential oils can be absorbed into the bloodstream through the nose.

The chemicals also stimulate the olfactory nerve in the nose directly, which could have effects on brain functioning.

Researcher Jemma McCready said ‘The difference between the two groups was 60-75 per cent, for example one group would remember to do seven things compared with four tasks completed by those who did not smell the oil, and they were quicker.

‘We deliberately set them a lot of tasks, so it’s possible that people who multi-task could function better after sniffing rosemary oil.’ Miss McCready said ‘There was no link between the participants’ mood and memory. This suggests performance is not influenced as a consequence of changes in alertness or arousal.

‘These findings may have implications for treating individuals with memory impairments.

‘It supports our previous research indicating that the aroma of rosemary essential oil can enhance cognitive functioning in healthy adults, here extending to the ability to remember events and to complete tasks in the future.

‘Remembering when and where to go and for what reasons underpins everything we do, and we all suffer minor failings that can be frustrating and sometimes dangerous. ‘Further research is needed to investigate if this treatment is useful for older adults who have experienced memory decline’ she added.

Florian Birkmayer: aromatherapists & psychiatrist

Florian BirkmayerFlorian Birkmayer, M.D., founded the Birkmayer Institute in 2009 to offer holistic person-centered psychiatry and addiction medicine as well as seminars and workshops on a wide range of holistic topics to facilitate self-transformation and continued self-development. This approach has been inspired by C.G. Jung’s ideas about Individuation, which is the journey of the limited ego to the Higher Self. His emphasis in holistic psychiatry is on Equine-assisted therapy, person-centered psychotherapy and holistic medication management including aromatherapy.

I met Dr. Birkmayer in February 2013, when he attended a weekend seminar I gave at the College of Botanical Healing Arts in Santa Cruz. The Birkmayer Institute is located in Albuquerque, New Mexico.

Robert: Not many psychiatrists use essential oils in their practice, in fact I can’t think of any others. What have been your main reference points for how to proceed using essential oils?
Dr. Birkmayer: You are correct that not many psychiatrists use essential oils and I feel like any pioneer in that I’ve had to proceed carefully. My main reference points for using essential oils have been holistic providers, many of whom recognize the interactions between emotional and physical symptoms. Also I have learned a lot from my clients, who are really the experts on their own well-being. Essential oils fit nicely into a client-centered and self-empowering approach. Sylla Sheppard-Hanger’s book The Aromatic Mind has been a very useful guide, as well as Salvatore Battaglia’s Complete Guide to Aromatherapy. There are also several books about the safety, including your Essential Oil Safety, that are very valuable. Unlike many psychiatrists, my clients are generally very interested and willing to try essential oils and report benefits and that is what has kept me going.

Are there different rationales for essential oil use in psychiatry?
I see several rationales: First and foremost, many medications and the approach of many psychiatrists is disempowering to clients, and essential oils restore a client’s sense that there’s something they can do, that empowers them to change their emotional state and cope better. Also, many clients that seek me out have experienced serious side effects and limited benefit from their psychiatric medications and are seeking gentler approaches. However I don’t want to ‘throw the baby out with the bath water,’ and for many clients we use a combination of medications and essential oils. I use the oils both to alleviate symptoms and enhance well-being and coping, but also to counteract side effects of medications.

Are you looking for specific effects from specific oils, or is it all basically ‘feel-good’, or do you use fragrance to anchor feelings?
I use essential oils for specific effects, such as enhancing mood or alleviating anxiety or insomnia as well as to counteract certain side effects of medications. What you refer to as ‘feel-good’ I see as the enhanced sense of well-being that clients get from regaining a sense of resilience and improved coping skills with regards to their symptoms and life stressors. This also allows clients to shift from being symptom-focused to being ‘strengths based’ or ‘recovery oriented.’ In many cases, I tell clients to think of an intention or positive thought when they apply the essential oils, so in addition to the specific effects, the oils can thereby anchor feelings and intentions, or, more broadly, an enhanced sense of self-efficacy.

What type of complaints do you see most?
The most common complaints I see are related to traumic experiences, as well as anxiety, depression, insomnia and side-effects from medications.

Do you mostly use single oils or blends? Why?
I use both single oils as well as blends of up to four or five oils. In my psychiatric practice I’ve met many clients that are on multiple medications, which increases the chance of drug interactions and side effects and one of my core approaches is to simplify medication regimens as much as possible. Similarly when I use oils I try to use a minimum number – it’s more elegant and it’s gentler on the client’s brain.

Do you allow some clients to pick their own oil or blend?
Most of the oils and blends I offer are customized for the individual client with input from them. During a visit, I select a few oils that I feel might be helpful and let the clients smell them and choose the oils that agree with them. The olfactory nerves go directly to the limbic system, which is the part of the brain that processes emotions, and thus how a client reacts to a smell to me is an indication of what their limbic system may need at that time.

What do you hope for in terms of the effects of the oils?
There are many specific effects related to sleep, anxiety, mood, but above all I hope to restore a client’s sense of self-efficacy, so they can cope better with their lives and that the oils become ‘tools in their toolbox of coping skills.’

What are some of your favorites, and what do you mostly use them for?
I have many favorites, but recently I’ve been particularly fond of a simple combination of melissa (lemon balm) and palo santo essential oils which I have given several clients with anxiety and trauma-related issues and it appears to allow people to center themselves and let go of feeling overwhelmed.

Can you describe one or two of your cases where essential oils have played a major role in mental health improvement?
I have a simple blend that I call Sleep Oil that I developed and started using for myself and then shared with colleagues and then with clients – insomnia is a very common problem – and the response has been overwhelming. People are always asking me for more Sleep Oil, giving it to relatives and raving about it. One of the cool things about using this is that it’s applied to the skin. Many people are used to having to ingest something, a medication or a supplement, to get help with insomnia, so when they use Sleep Oil, they unlearn that they need to ingest something to sleep and that goes a long way towards restoring a natural sleep pattern.

Another example: As you may know, some psychiatric medications cause sexual side effects, which can be very distressing. I’ve had success with several clients in overcoming these side effects by using ylang-ylang diluted in a carrier oil and topically applied.

So how exactly are your essential oils used – does it always involve topical application? To skin?
I’ve been using topical application, which I tell clients to think of as anointing themselves as well as sprays which I tell clients to consider their ‘signature scent’.

Dr. Birkmayer with ShadowApart from treating clients, what are some of your other activities?
One of the goals of The Birkmayer Institute is to offer seminars on a wide range of holistic topics, including aromatherapy. I’ve been teaching a monthly seminar on C.G. Jung’s Red Book for the past year, which has been a remarkable journey. Apart from essential oils and Jung, my greatest passion is equine assisted therapy and I have been blessed that my relationship to horses has gotten deeper and more profound through providing equine assisted therapy and experiencing the healing power of horses. Several times a year, I host a retreat for healers called ‘Horses Healing Healers.’

Do you see any signs that conventional medicine is becoming any more open to the use of unconventional therapy, especially essential oils? Could aromatherapy transform psychiatry?
The clients are very eager for new, more gentle and transformative approaches. However, the field of psychiatry acts reserved and skeptical, even more than providers in other medical specialties, at least on the surface. In private I’ve had several colleagues, especially nurses but also a few physicians, express great interest. My dream is to organize a conference on holistic – especially aromatic – psychiatry in the next couple years, as I suspect there’s a lot of hunger for knowledge.

Dr. Birkmayer received his B.A. from Princeton University and his M.D. from the College of Physicians and Surgeons of Columbia University. He completed his psychiatry residency at the University of New Mexico. He has previously served as the director of the Dual Diagnosis Clinic at University of New Mexico Psychiatric Center and as the director of the Substance Use Disorders program at the Veterans Affairs Medical Center in Albuquerque, NM. He was invited to be a full member of the Group for the Advancement of Psychiatry. He has a long-standing commitment to working with the underserved, e.g. working with Na’anizhozhi Center Inc., a Navajo-tradition based detox and rehab center in Gallup, NM and providing tele-psychiatry to underserved areas. He views himself as a bridge-builder between different medical worlds and works closely and respectfully with a wide range of healers.

Essential oils and eye safety

There has been much social media discussion recently (February 2012) about the wisdom or otherwise of putting essential oils into your eyes to treat eye problems. This arose from two webpages, here and here. One of these, on the Livestrong website, states: “More and more people are choosing to use alternative medicines to treat minor illnesses rather than taking a prescription. Putting essential oils in or near the eyes isn’t something that is widely known about, but there are several that can aid in the treatment of eye problems. Before using essential oils for your eyes, always contact your doctor.

Clary sage is the essential oil that is most widely used to treat vision problems. It is placed in the eye, so advice from an optometrist is important before use. Clary sage is used as a cleanser for the eyes. It can also be used to clear eye sight due to foggy vision or an injury to the eyes. Clary sage can also be used to brighten the eyes and improve vision. Finally, it can have beneficial results for people with eye issues related to aging” (Eliza Martinez).

Damage to the cornea after inadvertent adminstration of Olbas Oil. Courtesy of Nature Publishing Group

This actually dates from May 2010, but judging from the related comments, has only recently been noticed. The statement that “Clary sage is the essential oil that is most widely used to treat vision problems” is not true, since there are no essential oils commonly used to treat vision problems. The only evidence for any essential oil treating any eye problem relates to tea tree oil and eyelash mites (see below). The reference to clary sage probably derives from 17th century European herbalists, but this refers to using clary sage seeds, or mucilage made from them, and not to clary sage essential oil: “The seed put into the eyes clears them from motes and such like things gotten within the lids to offend them, and it also clears them from any white and red spots which may be on them” (Culpeper 1652). Another common name for clary sage (Salvia sclarea) was “clear eye” because of this common use of the seeds, which probably pre-dated Culpeper by many years. “Clary” may derive from “clear-eye.”

Not only is there no evidence that any essential oil can help with vision problems, age-related or otherwise, but placing any essential oil “in the eye” is extremely dangerous advice. Almost any undiluted essential oil coming into contact with the ocular membranes will be corrosive, possibly causing scarring of the cornea, and certainly causing significant pain.

Eye damage
I could find no reports in the literature of ocular accidents involving single essential oils, but there are several for Olbas oil. This is a mixture of essential oils and menthol:

35.45% Eucalyptus oil
35.45% Dementholized mint oil
18.5% Cajuput oil
4.1% Menthol
3.7% Wintergreen oil
2.7% Juniper berry oil
0.1% Clove oil

A 2009 report from an ophthalmologist in Bristol UK, describes partial loss of corneal tissue (ie erosion) when a 73-year-old man dripped Olbas Oil into his left eye (he had no right eye) because he thought he was using eye drops (see picture above). He was “considerably incapacitated”, but recovered after a week of treatment with “topical antibiotics and lubricants”. On checking, the author found that just his hospital, in the previous 18 months, had seen 12 patients who had mistakenly dripped Olbas Oil into one eye. He describes the result as a chemical burn, though he found that Olbas Oil in tears was pH neutral (most chemical burns are caused by substances that are strongly acid or alkaline). All “Olbas Oil patients” recovered fully within one week following intensive treatment (Adams et al 2009).

Olbas Oil may cause problems even when not applied directly to the eyes. The mother of a 4-month-old boy placed several drops of Olbas Oil in his right nostril in an attempt to help his respiratory infection, not realizing that the product warns against use in infants. The child immediately showed signs of respiratory distress, and was taken to the emergency room. Two hours after admission his eyes became inflamed, and examination revealed bilateral superficial corneal scarring. He also had conjunctivitis, and could not open his eyes. They were flushed with saline over four days, and he recovered with no residual scarring (Wyllie and Alexander 1994).

Emergency treatment
More than 65,000 work-related eye injuries and illnesses are reported annually in the USA, a “significant percentage” of these being ocular chemical burns. They require rapid treatment, and severe burns have a poor prognosis. The standard treatment is copious irrigation with saline solution for 1-2 hours. Contact lenses should not be removed initially (Peate 2007). With essential oils, fatty oil has been suggested as an appropriate first aid treatment though the advantage of saline is that the eyes can be continually flushed, and this is less easy with fatty oil.

What about diluted essential oils?
The second article describes using essential oils diluted to (by my estimation) about 3%. It includes the following advice:

“Here is a truly natural solution, which has been shown to benefit your eye health and the only one I will use. Gary Young has used this recipe for his patients at the Ecuador Clinic for macular degeneration, health issues, cataracts, and improving sight. I’ve been using it for a couple of years and love it! I started using this recipe before I had to have a vision exam in order to purchase new contacts. And I knew my vision had deteriorated from my last exam. So I put the drops in my eyes every night for about 6 months prior to the exam and my prescription had not changed according to their records, but I know what I was not seeing and I know what I was seeing as a result of using these drops – clearly my vision had improved! The recipe is as follows:

 7-10 drops of Frankincense
7-10 drops of Rosemary
7-10 drops of Cypress
2 Tbsp of V-6

Put oils in a glass dropper bottle with a lid on it. My experience has been that I can see much more clearly just after putting the drops in my eye so I am also going to experiment with putting a drop in my eyes in the morning” (Diana Ewald).

“V-6” is a proprietary blend of vegetable oils. The above implies that using these oils on a daily basis is likely to have a healing effect in cases of cataract, macular degeneration or failing eyesight. Although the article continues to describe various effects of the essential oils, none of them have any relationship with any of these conditions. So the question arises – how to weigh potential benefits against potential risks?

The word “experiment” in the above seems appropriate. Eyesight problems are difficult to treat, and once damage has occurred, recovery is not always simple. A 3% dilution may not be sufficient to cause corneal erosion, but on the other hand there is no evidence of any benefit. One concern is that the wrong dilution may be used, and the risk of this is substantial. For example, it would be easy to confuse “tbsp” with tsp”, resulting in a dilution of about 10% instead of 3%.

In a Chinese study, an ointment containing 5% tea tree oil was used by patients whose eyelash follicles were infested with “eyelash mites” (Demodex folliculorum). The ointment was applied to the lid margins with eyes closed, daily for 4 weeks after washing the face, and resulted in considerably less itching and fewer mites. Two of the 24 patients experienced slight irritation from the ointment. The 5% concentration was arrived at after preliminary testing using various dilutions on rabbit eyes (Gao et al 2012).

* Undiluted essential oils should not be applied to the eyes.

* It is rash to suggest that essential oils are commonly used to treat eye problems

* Eye injuries and diseases are medical conditions, and any product claiming to treat them is a medicine, subject to drug legislation.

* There is currently no evidence that applying dilutions of essential oil to the eyes will be beneficial in any condition.

* Diluted (5%) tea tree oil may help eradicate eyelash mites, but it should not be placed into the eyes.

Adams MK, Sparrow JM, Jim S et al 2009 Inadvertent administration of Olbas oil into the eye: a surprisingly frequent presentation. Eye (London) 23:244

Culpeper N 1652 The English Physitian, or an Astro-physical discourse of the vulgar herbs of this nation. Being a compleat method of physick, whereby a man may preserve his body in health; or cure himself, being sick. Thomas Kelly, London

Gao YY, Xu DL, Huang IJ et al 2012 Treatment of ocular itching associated with ocular demodicosis by 5% tea tree oil ointment. Cornea 31:14-17

Peate WF 2007 Work-related eye injuries and illnesses. American Family Physician 75:1017-1022

Wyllie JP, Alexander FW 1994 Nasal instillation of ‘Olbas Oil’ in an infant. Archives of Disease in Childhood 70:357-358

This article also appears in the International Journal of Professional Holistic Aromatherapy, Vol. 1 Issue 4

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