2.Glycolic Acid

Glycolic acid, a type of alpha-hydroxy acid, is one of our favorite secret weapons for chemical exfoliation. It battles both acne and wrinkles and it also offers a slew of other skin-loving benefits.When applied to the skin, acne products containing glycolic acid weaken the “glue” that holds dead skin cells together.In a nutshell, by eliminating the buildup of oils and dead skin cells, glycolic acid ensures the pores are less likely to become clogged and acne breakouts are less likely to occur.
Dr. Cheung says. Production of collagen slows as we age. In fact, according to Scientific American, after age 20, that production will begin declining by an estimated 1 percent annually.

Where can buy – you can get it from drug stores and beauty stores in different versions like cleansers, serums, peels and moisturizer.but if you need something more powerful you consult your dermatologist for an peel type.