menthol

Menthol is an organic compound belonging to the class of monoterpenoid alcohols. It has the chemical formula C10H20O and occurs as a colorless, crystalline solid at room temperature. Menthol exists in several stereoisomeric forms; the natural form is (-)-menthol, the predominant enantiomer in peppermint and other Mentha species. It can also be produced synthetically.

Menthol is primarily obtained from essential oils of Mentha species, especially Mentha piperita (peppermint) and Mentha arvensis, by steam distillation followed by purification and crystallization. The essential oils contain a mixture of menthol stereoisomers, with (-)-menthol being the most desirable for flavor and cooling properties.

The characteristic cooling sensation of menthol arises from its activation of the transient receptor potential channel TRPM8 in cutaneous sensory neurons. This cooling effect is separate from taste and is widely exploited in consumer products. Menthol can also have mild local anesthetic effects and may provide temporary relief of minor irritations.

Menthol is used in foods and beverages as a flavoring agent and scenting additive in gums, candies, and confectionery. In pharmaceuticals and personal care products, it serves as a cooling agent in cough drops, lozenges, throat sprays, ointments, creams, and topical gels, often alongside analgesics. It is also used as a fragrance component in cosmetics and as a scent additive in various products.

Menthol is approved for use in regulated concentrations in foods and personal care products in many jurisdictions. It can cause skin irritation or an allergic reaction in sensitive individuals and may be harmful if ingested in large amounts. As with all ingredients, usage is subject to regulatory guidelines.