Alpha-Hydroxy Acids (AHAs)Alpha-hydroxy acids include glycolic, lactic, tartaric, malic, and citric acids. They have become increasingly popular over the last 20 years. In the U.S. alone, there are over 200 makers of skin care products containing alpha-hydroxy acids. Creams and lotions with alpha-hydroxy acids may help with fine lines, irregular pigmentation, and age spots. Side effects of alpha-hydroxy acids include mild irritation and sun sensitivity.
Beta-Hydroxy Acid (Salicylic Acid)Salicylic acid exfoliates skin and can improve its texture and color. It also helps with acne.
Many skin care products contain salicylic acid. Some are available over-the-counter and others require a doctor's prescription. Studies have shown that salicylic acid is less irritating than skin care products containing alpha-hydroxy acids but has similar results in improving skin texture and color.
Warning: People who are allergic to salycylates (found in aspirin) should not use products containing salicylic acid. Salicylic acid can be absorbed into the bloodstream and may cause an allergic reaction or contact dermatitis. Pregnant or nursing women should not use products containing salicylic acid.
HydroquinoneSkin care products containing hydroquinone are often called bleaching creams or lightening agents. These skin care products are used to lighten hyperpigmentation, such as age spots and dark spots related to pregnancy or hormone therapy (also called melasma). Some over-the-counter skin care products contain hydroquinone. Your doctor can also prescribe a product with a higher concentration of hydroquinone if your skin doesn't respond to over-the-counter treatments. If you are allergic to hydroquinones, you can use products containing kojic acid instead. Pregnant women cannot use hydroquinone.
Kojic AcidKojic acid is a more recent remedy for treating pigment problems and age spots. First developed in 1989, kojic acid has a similar effect as hydroquinone. Kojic acid is made from a fungus, and studies have shown that it is effective at lightening skin.
RetinolRetinol is made from vitamin A, and it's in many non-prescription skin care products. Retinol's stronger counterpart is tretinoin, which is the active ingredient in Retin-A and Renova, available by prescription only. If your skin is too sensitive to use Retin-A, retinol is an alternative, although the effects are less impressive. Retinol may improve mottled pigmentation, fine lines and wrinkles, skin texture, and skin tone and color.
You may also hear about retinyl palmitate. This is in the same family as retinol, but if the skin care product you choose contains retinyl palmitate, you will need to use more of this product than one that contains retinol to get the same effect. Pregnant women or nursing mothers cannot use retinol.