The ingredient: Retinol
Also known as: Retinoids, retinoic acid, vitamin A
Found in: Anti-aging products, acne treatments, skin lighteners
Where it comes from: Retinol is a synthetically-made version of vitamin A.
What it does: This powerful antioxidant aids in cell repair and combats the free radicals that can lead to skin damage. In the skin, it inhibits the oil-producing sebum to prevent acne. It also encourages skin cells to replicate, which can help reverse sun damage and fine lines. This action may cause irritation or lead to sun sensitivity in certain people.
Expert source: Art Georgalas, a cosmetic chemist in Warwick, New York, and owner of Georgalas Endeavors, LLC
Plus, find out how to pamper your skin.