Different types of chemical peels provide different benefits to the skin. Glycolic and lactic acid are examples of two types of alpha hydroxy acids, which also are known as AHAs. An AHA peel means the peel is derived from fruit acids. When choosing a glycolic or lactic acid peel, consider the desired effects and your skin's current condition.
Glycolic acid is an AHA derived from sugar cane, according to LaraChem Inc. The acid molecules are small, making them ideal for penetrating the skin. Lactic acid is made from sour milk and is considered to be a milder peel than glycolic acid.
When a lactic acid peel is applied to the skin, the lactic acid particles penetrate the skin and help to kill germs and bacteria, according to LaraChem. Lactic acid also helps to reduce the bonds that hold dead skin cells to the skin, which can help to reduce age spots. Glycolic acid works similarly to release dead skin cells, but is slightly smaller in terms of molecule size, which means the peel may penetrate slightly deeper, according to 30 Glycolic. Because of this, glycolic acid reaches the dermis, which is the layer of skin underneath the epidermis. There, the glycolic acid stimulates collagen production, which can make the skin appear tighter.
The amount to which a glycolic or lactic acid peel penetrates and exfoliates the skin often depends upon what percentage of the chemical is used, according to LaraChem Inc. For example, those who have not experienced a glycolic or lactic acid peel before or who have very sensitive skin should start with a mild peel--between 10 and 30 percent.
Those with normal skin may be able to undergo a peel that is between 40 and 50 percent glycolic or lactic acid.
Glycolic acid is suitable for treating a number of conditions, including dark spots, wrinkles, acne, skin scarring, surface wrinkles, large pores and oily skin, according to 30 Glycolic. Lactic acid treats dark spots, wrinkles and sagging areas of skin, and is also effective in treating rosacea, according to LaraChem Inc.
If you have acne or are concerned about sagging or wrinkling skin, glycolic acid may be the more suitable peel ingredient because of its ability to penetrate the skin. However, those with sensitive skin may find glycolic acid too harsh for the skin because irritation can result. Also, those with the skin condition rosacea, which causes the skin to appear reddened, should undergo a lactic acid peel, according to the American Society of Plastic Surgeons. Glycolic acid can exacerbate rosacea.