[Essential oils: good advice by the pharmacist is necessary].

Essential oils are highly concentrated products of a complex composition, obtained from plants. Their therapeutic use relies mostly on tradition and experience. Often few clinical trials are available. The quality and efficacy of only several essential oils are described in the European pharmacopeia and in monographs of the EMA. In addition, essential oils on the Belgian market have different statutes [medicine, food supplement, raw material...]. This results in a complicated legislation. Furthermore, the general public wrongly assumes that essential oils, because of their vegetal origin, can be used at any time without any danger. However, toxicological reactions are described after oral, topical and other routes of administration. Certain precautions need to be taken before using potentially hazardous essential oils. Children and pregnant women are particularly vulnerable populations that need extra attention.