Peruse any skincare aisle and you will find rows of products boasting anti-wrinkle formulas. If you take the time to check the ingredients, you will invariably find retinoids—derivatives of Vitamin A.What are these wrinkle-erasing elixirs? YouBeauty is here to explain how they work, what they’re in and why one derivative in particular—retinyl palmitate—is accused of causing skin cancer.
Retin-A, in the beginning
Vitamin A is essential for healthy eyes and skin. It exists naturally in liver, butter and eggs, and its precursor, beta-carotene, is in colorful 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.In the late 1960s, Albert Kligman, M.D, Ph.D., a dermatologist at the University of Pennsylvania, started testing 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.”MORE: How Your Skin Ages
How to erase a wrinkle
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 and sunlight
Retinoids degrade in light, which is why most dermatologists recommend nighttime application.The discovery that retinoids were photosensitive was, in part, pure luck. James Leyden, M.D., Kligman’s colleague, tells YouBeauty that their team ran out of brown test bottles during the experiments and had to put some tretinoin mixtures in clear bottles. The mixtures in the clear containers stopped working sooner than their counterparts, showing that tretinoin was unstable when exposed to light.Contrary to Retin-A lore, however, the drug does not increase the skin’s photosensitivity (sensitivity to light) in the strictest sense. Technically, photosensitivity happens when a molecule absorbs light and produces a chemical that damages the skin.
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.”