Ingredients such as menthol, peppermint, camphor, and mint are counter-irritants (Sources: Archives of Dermatologic Research, May 1996, pages 245–248; and Code of Federal Regulations Title 21—Food and Drugs, revised April 1, 2001, CITE: 21CFR310.545, www.fda.gov). Counter-irritants are used to induce local inflammation for the purpose of relieving inflammation in deeper or adjacent tissues. In other words, they substitute one kind of inflammation for another, which is never good for skin. Irritation or inflammation, no matter what causes it or how it happens, impairs the skin’s immune and healing response (Source: Skin Pharmacology and Applied Skin Physiology, November–December 2000, pages 358–371). And although your skin may not show it or doesn’t react in an irritated fashion, if you apply irritants to your skin the damage is still taking place and is ongoing, so it adds up over time (Source: Skin Research and Technology, November 2001, pages 227–237).