Topical skin lightening cosmeceuticals are becoming more popular. They have been used alone and in combination therapy. In medical practice they are sometimes used as maintenance agents, and very seldom used in patients who are unable to tolerate various prescription medications or in place of other properties such as antioxidants, anti-aging products, or moisturizers.
Commonly used depigmenting agents include arbutin, ascorbic acid, bearberry extract, idebenone, indomethacin, licorice extract, melawhite, mercury, and mulberry plant extract (Table 3). No controlled studies investigating the efficacy and safety of these compounds have been conducted, and although insufficient data exist to conclude their efficacy, successful results have been published (26).
Thioactic acid (alpha-lipoic acid) is a disulfide derivative of octanoic acid that inhibits tyrosinase activity and prevents UV-induced photodamage. Clinical data proving its efficacy are minimal (27).