Maybe the term acid reminds burning and damaging you, but there are some excellent acids for skin treatments. They are safe enough that they can even be used for sensitive skin. Acids for cosmetics and skin care products are divided into two main groups: 1) Alpha hydroxy acids (AHA) or fruit acids which can help to exfoliate, lighten, improve skin and have anti-ageing applications too, citric acid, glycolic acid, lactic acid, malic acid and tartaric acid are AHAs. 2) Beta hydroxy acids (BHA) are helpful for oily skin and help remove acne. Salicylic acid is a BHA. Also, some other ingredients like hyaluronic acid as a moisturizer and vitamin C (ascorbic acid) as a skin lightener acid with anti-aging effects.