Vitamin A is essential for healthy eyes and skin. Naturally found in liver, butter and eggs, and its precursor, beta-carotene, is in vegetables such as carrots, sweet potatoes and spinach. In order for the skin to benefit from Vitamin A, the body converts it to retinoic acid.
Several decades ago, this connection led dermatologists to pinpoint topical retinoids that effectively break down into retinoic acid as effective treatments for various skin ailments.
Albert Kligman, M.D, Ph.D., a dermatologist at the University of Pennsylvania, started testing in the late 1960s, a Vitamin A derivative called tretinoin on acne patients. By 1973, Kligman patented his formula for Retin-A, the first-ever effective acne treatment.
About twelve years later, Kligman and Leyden noticed Retin-A’s other lucrative effects: tretinoin patients had few wrinkles and smooth skintones. Kligman secured another set of patents, and the rest of the cosmetic industry soon followed with an abundance of anti-wrinkle retinoid treatments.
“Retinoids prevent wrinkles,” says Miami dermatologist and retinoid expert Leslie Baumann, M.D. “And, they are the only topical product that gets rid of wrinkles you already have.”
Retinoids bind to corresponding receptors in the skin. This peels off the top layer, which evens skin tone, and thickens the layers below, which smoothes out wrinkles. Retinoids also boost collagen, a protein that keeps the skin firm and springy, by blocking the genes that cause it to break down and increasing other gene activity responsible for its production.
Retinoids degrade in light, which is why most dermatologists recommend nighttime application.
With Retin-A, this is not the case. Instead, tretinoin molecules make the skin more sensitive to light by thinning the outer layer of skin by about a third, the equivalent of lowering its natural SPF by a few points. This means that the skin is more sensitive to sunburn. But, it does not mean that Retin-A produces harmful chemicals in sunlight.
“It’s true that if you used Retin-A and you were a lifeguard in the middle of July in Ocean City, NJ—that would be stupid,” says Leyden, the Retin-A researcher, “But if you apply it, an hour or so passes and then you go out and get in your car, that is not a problem.”