AHA stands for alpha-hydroxy acids, which are also commonly referred to as fruit acids. We've already talked about how glycolic acid is the top dog in the alpha-hydroxy family, but it's not the only acid used for AHA peels. Lactic acid and citric acid might be used in combination treatments, and chances are you've already had experiences with both [source: Hilinski]. Lactic acid is responsible for that burning sensation you feel in your muscles when you do something strenuous, and citric acid is found in all citrus fruits, such as oranges and lemons. Another alpha-hydroxy acid commonly used in chemical peels is salicylic acid [source: Levine].
Many AHA peels are sold in over-the-counter kits, but the concentration of acid tends to be low and consequently the results tend to be less noticeable. For more visible results, AHA peels can be administered in higher concentrations by a qualified physician. The solution is usually applied with a sponge, and the amount of time it's left on the skin depends on its concentration. Alpha-hydroxy acids help separate dead skin from healthy skin, and once this process is complete they can be neutralized using water. All in all, it shouldn't take more than 10 days to completely recover from an AHA peel.
The results of an AHA peel aren't necessarily drastic. In fact, it might take multiple treatments to achieve your desired result, but it can be effective in smoothing skin and evening out skin tone. It also tends to be a popular treatment for acne and reducing acne scars [source: Bernstein]. If you have sensitive skin, you'll probably want to stick with an AHA peel as opposed to some of the deeper peels on the market. You doctor should be able to help you decide which type of AHA peel is best for you.
Keep reading to find out about the strongest type of chemical peel.