The first contraindication is related to a possible allergy to one or more essential oils. In this case, it is better to favor another natural medicine. The other contraindications concern:
Pregnant women, who are prohibited from HE during the first trimester of their pregnancy because they can pass into the placenta and endanger the fetus. Subsequently, certain essential oils (tea tree, basil, lemon, ginger, etc.) containing no toxic molecules are usable (percutaneous, olfactory, sublingual, etc.).
The 3 golden rules of pharmacist Danièle Festy:
First, I do not swallow any HE during my first 3 months of pregnancy, without express advice from a competent professional. Except lemon or ginger against nausea.
Secondly, I follow a short EO-based treatment: either punctually (in a single dose), or for 5 to 10 days maximum.
And third, I never apply HE to my abdominal area.
Nursing mothers, because the essential oils pass into the milk.
Children in whom some essential oils risk causing nervous disorders. They are therefore contraindicated before 7 years of age.
It should also be noted that they can interact with certain treatments (for example in the case of hyperthyroidism or hypothyroidism), have a deleterious effect in people with epilepsy or even reduce or cancel the effectiveness of a homeopathic treatment.