Menthol occurs naturally in peppermint and other Mentha species essential oils and is also produced synthetically from thymol or citronellal. The natural form (L-menthol or (-)-menthol) is the most commercially important enantiomer, responsible for the classic cooling sensation via activation of TRPM8 receptors. Commercial grades include natural crystalline menthol (extracted from Mentha arvensis) and synthetic L-menthol.
Its melting point of approximately 42–44°C allows it to be incorporated into both solid confectionery and liquid formulations. Used at levels of 0.01–0.5% in food applications, higher (1–3%) in chewing gum and confectionery, and up to 5% in oral care products. Menthol is GRAS (FEMA 2665), FDA 21 CFR 182.20, and globally approved. It has documented antimicrobial, mild analgesic, and decongestant properties.