Menthol is a naturally occurring organic compound that is used in cosmetics and personal care products as a denaturant, topical analgesic, fragrance ingredient, and flavoring ingredient.
Menthol is an organic compound that can be obtained from peppermint, corn mint, or other mint oils. Mentha arvensis (wild mint) is the primary species of mint used to make natural menthol crystals and natural menthol flakes. Menthol can also be synthetically produced. It is a waxy, crystalline substance, clear or white in color, which is solid at room temperature and melts slightly above.
In addition to use in the cosmetic industry, menthol is also a component of several over-the-counter (OTC) medications because it has local anesthetic and counterirritant properties. A counterirritant is a substance which creates irritation or mild inflammation in one location with the goal of lessening discomfort and/or inflammation in another location. For this reason, menthol is used in OTC cold medications as a topical antitussive, as well as in OTC anorectal drug products as an analgesic, anesthetic, and antipruritic.
In cosmetics and personal care products, menthol functions as a denaturant, topical analgesic, fragrance ingredient, and flavoring ingredient.
Menthol is classified as a denaturant by the U.S. Bureau of Alcohol, Tobacco, and Firearms. Denaturants are used in products that contain ethanol, which is the same alcohol found in beverages such as liquor, wine, beer, etc. In the United States, alcoholic beverages are heavily taxed. In order to avoid paying beverage taxes on alcohol that is not meant to be consumed (i.e. for use in cosmetic and personal care products), the alcohol must be denatured per specific formulations given by the U.S. Government’s Alcohol and Tobacco Tax and Trade Bureau (TTB). The process adds a small amount of a denaturant to the alcohol to make it taste bad, thus creating alcohol that is not suitable for drinking, but is otherwise similar for other purposes.
Menthol can also function as a topical analgesic (pain reliever) in certain skin care products. Upon topical application, menthol produces a cooling sensation. Rather than lowering the temperature of the skin, the cooling effect occurs when menthol blocks the calcium current along the nerves responsible for detecting temperature. The nerve endings translate a message to the brain that the skin is cooling. The cooling sensation provided by menthol makes it a very useful ingredient for after-sun products, such as creams, lotions, and gels, because it alleviates the hot, painful sensation caused by overexposure to the sun. Menthol is also found in products that can be applied topically to the forehead in order to relieve pain due to headaches.
Other uses for menthol in cosmetics and personal care products include as a fragrance and flavoring ingredient. Menthol has a characteristic minty taste and smell. Lastly, menthol is used in lip care products because it improves blood flow to that area, resulting in a temporary plumping effect.
The United States Food and Drug Administration (FDA) includes menthol on its list of substances considered Generally Recognized As Safe (GRAS) for use in food. It is also an approved direct food additive. The FDA has also determined that menthol is safe and effective in OTC cold drug products as a topical antitussive and in OTC anorectal drug products as an analgesic, anesthetic, and antipruritic. Studies by the US National Toxicology Program have determined that menthol is not genotoxic or carcinogenic.
The safety of menthol has also been evaluated and rated on EWG’s Skin Deep Cosmetic Database. According to the Cosmetic Database, menthol is rated as a 1 on a scale of 1 to 10, with 1 being the lowest risk to health and 10 being the highest.
References: Wikipedia “Menthol”, Wikipedia “Counterirritant”, SkinStore “Everything You Need to Know About Menthol”, Cosmetics Info “Menthol”, EWG’s Skin Deep Cosmetic Database “Menthol”