Menthol is a covalent organic compound made synthetically or obtained from peppermint or other mint oils. It is a waxy, crystalline substance, clear or white in color, which is solid at room temperature and melts slightly above. The isopropyl group is stereochemically of trans- orientation to both the methyl and alcohol groups.

Menthol has local anesthetic and counterirritant qualities. It is contained in non-prescription products for short-term relief of minor sore throat and minor mouth or throat irritation. Menthol is also contained in combination products used for relief of muscle aches, sprains, and similar conditions. It is also used as an additive in certain cigarette brands, both for flavor and to reduce the throat and sinus irritation caused by smoking.

Menthol is believed to interfere with the effects of homeopathic remedies, and its use is strongly discouraged for those seeking homeopathic cures -- to the point of prohibiting use of mint flavored toothpaste. Currently no other reported nutrient or herb interactions involve menthol. Menthol is available as a dietary supplement or natural medicine in the form of peppermint oil. It is used in Eastern medicine to treat indigestion, nausea, sore throat, diarrhea, colds, and headaches.