What is Menthol?  

Menthol is an organic compound naturally occurring in mint plants. It is also synthetically manufactured. Menthol is widely used in a number of products and features certain therapeutic qualities. It was first isolated from peppermint oil in 1771 in the West, but it may have been in use in Japan for much longer.

Most of menthol's uses are related to its stimulation of the skin's cold receptors. This property makes menthol produce a cooling effect when inhaled or applied to the skin. Similarly to the capsaicin chemical found in hot peppers, which stimulates heat receptors, menthol does not actually change the skin's temperature, but merely produces the sensation of temperature change.

Because of its cooling effect, menthol is used in products meant to relieve skin irritation, sore throat, or nasal congestion. It may be used to treat sunburn, fever, or muscle aches as well. In traditional Asian medicine, menthol may be prescribed for nausea, diarrhea, indigestion, headache, cold, or sore throat. When used as a supplement for health reasons, menthol is usually taken in the form of peppermint oil. Products that commonly contain menthol include toothpaste, cough drops, lip balm, mouthwash, gum, and cigarettes