Menthol Worst Irritant No known benefits Menthol at a glance Plant extract derived from peppermint Used as a fragrance in skin care and cosmetics Offers a unique cooling sensation when applied topically Can cause skin sensitization Menthol description Derived from peppermint, menthol can have the same sensitising effect as peppermint on skin. Despite its documented ability to sensitise skin, menthol is included in a surprisingly large number of products. Unfortunately, the cooling, refreshing sensation menthol causes is direct evidence that your skin is being sensitised, not soothed. Related ingredients: Peppermint Menthone