Derived from peppermint, menthol can have the same sensitizing effect as peppermint on the skin. Despite its documented ability to sensitize the skin, menthol is included in a surprisingly large number of products. Unfortunately, the cooling, refreshing sensation that menthol causes is direct evidence that your skin is being sensitized, not soothed. https://www.paulaschoice.com/ingredient-dictionary/ingredient-menthol.html?q=Menthol&fdid=ingredients