Alpha-hydroxy acids hydroquinone

The first one that was recognized as being effective was retinoic acid. This was a prescription ointment drug until the over-the-counter product was approved in the mid-nineties, and proved efFective. Another is glycolic acid, which is available in makeup products or in more concentrated forms from physicians. There is also Kojic acid, alpha hydroxy acid, beta hydroxy acid, and the newest vitamin C products. Hydroquinone is another chemical that is used because it has a bleaching effect on the skin. 

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