Dear Mr. Tisserand,

I was treating a young woman with back pain recently. This young woman is on selective serotonin re-uptake inhibitor (SSRI) type of anti-depressant medication. Because her pain was acute I used a 10% blend on the specific site of pain that included German chamomile, black pepper, ginger and everlasting. About 30 minutes after the application she vomited and told me she suspected the essential oils may have caused her to be sick. She mentioned serotonin syndrome which is caused by an overload of serotonin in her system.

I referred to quite a few texts (including your book) and could not find any contraindications listed. I did find some notes that my aromatherapy lecturer gave me that states chamomile, lavender, marjoram, and neroli have the action of releasing seratonin in the system when used.

Are there any active chemicals (eg linalool or some other) that might have this effect that you are aware of? I would appreciate any help you could provide.

Kind regards
-Liliana

Dear Liliana,

Tough question. I wonder how much total oil you applied to her body? And what proportions you used of each oil? Only about 10% of that would be absorbed by the skin, so 10% EO applied becomes 1% EO absorbed. It’s then a matter of whether enough oil got into her bloodstream to provoke such a strong non-local reaction. It’s not impossible.

Some oils do affect serotonin directly, but not massively. It’s more likely that an oil/constituent increased the SSRI effect (so indirectly causing a further increase in serotonin), if indeed the essential oils were responsible for her vomiting. The only ones known to interact badly with SSRI drugs are eugenol-rich oils (such as clove) and myristicin-rich oils (such as nutmeg), and you used none of those. These two constituents are monoamine oxidase (MAO) inhibitors, which can cause this interaction with SSRI drugs.

If it was something you used, I would guess that it’s not the black pepper or ginger, which are rich in terpenes.

-Robert

Hi Robert

Thank you so much for your quick reply!

What you have said makes a lot of sense. In answer to your question: I did not give her a full body massage. I massaged the oils directly on the area, about 25 x 30 cm of her back to treat muscular inflammation. In 15 ml of carrier oil I mixed 12 drops German chamomile, 6 drops ginger, 6 drops black pepper and 6 drops everlasting (and not all of the oil was used up).

Thank you so much for your assistance.

Kind regards
-Liliana

In conclusion – very little essential oil, equivalent to 1 or 2 drops maximum, would enter the bloodstream from this treatment. If one of the oils did interact with the SSRI medication, it must be quite a potent MAO inhibitor.