Underarm skin may become darker than surrounding skin for reasons as simple as excessive sweating or friction from shaving with a dull blade. It may also be related to more persistent medical issues like hyperpigmentation or acanthosis nigricans, a skin condition resulting from excess insulin. Regardless of the cause, there are several types of skin creams designed to gradually lighten dark and discolored skin, many of which are marketed for the expressed purpose of lightening dark underarms.
Hydroquinone is the only cream approved to use the terms "skin bleaching" and "skin lightening" by the FDA, reports DermaDoctor. Hydroquinone interferes with the natural actions of tyrosinase, an enzyme that assists in the body's production of melanin, its natural pigment. It is available in the United States in both prescription and over-the-counter strengths, but due to some controversy over its possible side effects, some countries have prohibited its sale. Worries over hydroquinone include the potential for skin irritation, complications with fetal development and, with long-term use, the possibility for developing a skin condition called ochronosis, which can give the skin a blue or black discoloration. Despite these risks, the FDA has established hydroquinone as safe and effective, though it recommends that users limit their regimens to six months or less to minimize the chance of side effects.
Mitracarpus Scaber Extract Creams
Mitracarpus scaber extract is a botanical byproduct produced from the tropical plant of the same name and it is also capable of interrupting tyrosinase activity much like hydroquinone. The active substance in mitracarpus scaber extract, hauronoside, is one of two sister molecules of hydroquinone. Hauronoside is described by Dermadoctor as being both less irritating and more effective at skin lightening than hydroquinone, and creams that include this active ingredient are sometimes marketed specifically as alternatives of hydroquinone creams.
Bearberry Extract Creams
Dermadoctor identifies hydroquinone's other sister molecule as arbutin, which is the active substance in bearberry extract. Bearberry is the more common name for arctostaphylos uva ursi leaf, an herb with numerous applications in natural medicine, according to Herbwisdom.com. Ingredient labels on creams containing this substance may identify it as either bearberry extract, uva ursi leaf extract or simply arbutin. Like mitracarpus scaber extract, bearberry extract has been marketed as a safer alternative to hydroquinone.