Eugenol is a member of the phenylpropanoids class of chemical compounds, which are synthesized by plants from the amino acids phenylalanine and tyrosine. It is a colorless to pale yellow, aromatic oily liquid extracted from plant essential oils. It is found in high concentrations in clove oil, nutmeg, cinnamon, basil, and bay leaf.
In cosmetics and personal care products, eugenol is primarily used as a fragrance ingredient. It has a pleasant, spicy, clove-like odor. Eugenol is also used as a local antiseptic and anaesthetic. However, since it is a volatile fragrance chemical, it is known to cause sensitivity reactions, especially with leave-on products.