A person wearing black gloves paints a translucent paste on the face of a person who lies back in a chair. Chemical peels are a popular skin-care treatment with a growing market. Credit: Alamy ...

Glycolic acid is a substance that chemically exfoliates a person’s skin by dissolving dead skin cells and oils. Glycolic acid may also help boost collagen production, and support skin moisture.

Citric acid is a weak organic acid that occurs naturally in produce, such as citrus fruits. It is used in food, cosmetics, and cleaning products. Share on Pinterest vkbhat/Getty Images Citric acid is ...