Aromatherapy is a practice based on the use of aromatic materials, including essential oils and other aroma compounds, with claims for improving psychological well-being.

[2][3] The use of essential oils for therapeutic, spiritual, hygienic and ritualistic purposes goes back to ancient civilizations including the Indians, Chinese, Egyptians, Greeks, and Romans who used them in cosmetics, perfumes and drugs.

[8] In the era of modern medicine, the name "aromatherapy" first appeared in print in 1937 in a French book on the subject: Aromathérapie: Les Huiles Essentielles, Hormones Végétales by René-Maurice Gattefossé, a chemist.

[9] Jean Valnet, a French surgeon, pioneered the supposed medicinal uses of essential oils, which he used as antiseptics in the treatment of wounded soldiers during World War II.

[13] This does not make it possible to determine whether each component is natural or whether a poor oil has been "improved" by the addition of synthetic aromachemicals, but the latter is often signalled by the minor impurities present.

[21] Aromatherapy carries a number of risks of adverse effects; combined with the lack of evidence of its therapeutic benefit, the practice is of questionable worth.

[22] Many studies have explored the concerns that essential oils are highly concentrated and can irritate the skin when used in undiluted form, often referred to as neat application.

[31] Another article published by a different research group also documented three cases of gynecomastia in prepubertal boys who were exposed to topical lavender oil.

[34] A few reported cases of toxic reactions like liver damage and seizures have occurred after ingestion of sage, hyssop, thuja and cedar oils.

In late 2021, an aromatherapy spray was recalled after it was found to be contaminated with Burkholderia pseudomallei, the bacteria that causes melioidosis, which led to four cases of the disease and two deaths.