Lactic acid is also an AHA, and you might have guessed from the name that it’s often found in milk. Sour milk, that is, including yogurt, kefir, and cottage cheese. Interestingly, it’s also found in fresh, organic honey.
“Lactic acid is a popular ingredient in anti-aging and rejuvenating skin care products, as it is a relatively mild and gentle on the skin,” said Dr. Gray. It’s also a wonderful ingredient to calm acne-prone skin.
You can purchase mild concentrations over the counter or schedule an appointment with a professional for a more potent facial. For daily use, we recommend about a 10 percent concentration. If you have really irritated, peeling, or highly sensitive skin, consult your dermatologist before using.