Retinol, which is a vitamin A derivative, is the most effective topical ingredient for anti-aging—and the only one that is clinically proven. But for it to be effective, it has to reach a concentration in the skin of at least 0.60- 0.70%.

Typical over the counter retinol products, even the best selling one, only contain about 0.15%—not enough to make a meaningful difference. No matter how much you put on—you can put it on all night—you’ll never reach 0.60%

With a 1% concentration—like the Obagi tretinoin, you can activate and stimulate your skin cells so that they begin producing collagen and accelerate cellular turnover.

Retinol was first used to treat acne but is now frequently used to treat sun damage and signs of aging. Because it works underneath the surface of the skin, retinol creams can help fix deep wrinkles and damage those traditional moisturizers and creams cannot do much to improve. After a few weeks of use, skin will gradually begin to feel firmer and softer. Complexion will improve, and wrinkles, fine lines, and age spots will be reduced. Dead cells will be sloughed off as new cells begin to grow underneath and push their way towards the surface of the skin. Pigmentation will begin to look more even.