If your head is already spinning, don’t worry. The realm of retinoids and retinol can be pretty confusing. The bottom line: “Retinol” is a term for an OTC vitamin A compound, and it may very well be your skin’s new best friend. And as it turns out, retinol works hard to get to those retinol receptors. The retinol molecule “is able to penetrate the skin’s surface and activate a variety of cells in the skin,” explains board-certified dermatologist Melanie Palm, M.D., MBA. “In the second layer of the skin, retinol penetrates cells called fibroblasts—the major collagen builders of our skin.” From there, retinol crosses the fibroblast’s cell membrane, then enters its nucleus where it binds to the receptors. This commands the fibroblast to start building new collagen, contributing to healthier, smoother-looking skin. Retinol’s ability to support cell turnover and exfoliate becomes especially useful as we age. According to board-certified dermatologist Loretta Ciraldo, M.D., FAAD, we actually shed dead skin cells at a slower rate as we get older, but retinol can move things along. Top it off with retinol’s ability to induce glycosaminoglycan3—a compound that retains moisture—and you’ve got the perfect setup for a smoother and brighter complexion. For starters, sun exposure causes oxidative stress, which destroys collagen fibers. However, on a molecular level, retinol combats the effect by inhibiting metalloproteinases4, or collagen-degrading enzymes. Additionally, as it encourages cell turnover, it helps thicken the epidermis and even out hyperpigmentation5. Again, this is important as you get older. Cells in mature skin are slower to respond to wound healing1, which decreases their ability to rapidly grow and multiply. This occurs even if your skin isn’t significantly photodamaged; it’s a normal part of aging. But by adding retinol to your skin care lineup, you can give your skin a much-needed boost. After a pimple has come and gone, retinol can help decrease post-breakout scarring as well. In addition to exfoliating dead skin cells, retinoid blocks the activity of enzymes8 behind melanin synthesis, resulting in a more even skin tone. Retinol is ideal for those with acne-prone skin, too. As it improves the shedding of dead cells, your pores will be less likely to clog up, resulting in fewer breakouts. Retinol, along with its derivatives, can potentially cause unpleasant side effects, known as the “retinoid reaction” or retinoid-induced dermatitis. “Localized skin irritation—often redness and dryness—is the most common side effect of [using] retinol,” explains Palm. This can make it for people with sensitive skin to tolerate, she says. Other possible side effects include peeling, itching, and burning. Retinol can also increase photosensitivity10, says Ciraldo, especially at high concentrations. This means it makes your skin more sensitive to the sun, causing a rash or sunburn-like reaction when you’re exposed to sunlight. “This is why it’s recommended to use retinoids in the evening and protect your skin with a moisturizer with sunscreen during the day, so you get all the benefits and minimize the side effects,” says board-certified dermatologist Keira Barr, M.D. The good news, however, is that these side effects typically subside over time. The key is to be mindful of how you use retinol, especially if it’s your first time. It’s also wise to ease into regular usage. To start, Palm suggests applying it every third night. If you don’t develop a reaction after two weeks, start using it every other night. Then, after another two weeks, you can use it nightly or as tolerated. Don’t forget about the actual amount, too. “Always use, at most, a pea-size amount for the entire face,” advises Palm. It might not seem like enough, but it’s really all you need. As for layering? After cleansing and drying your face, add retinol first, says Palm. “[Follow with] other nighttime topicals, from lightest to heaviest in formulation.” But if you are extra-sensitive to retinol, you can layer retinol over moisturizer to buffer the effects. It might take some experimentation to see what works best for you. Finally, consider the state of your skin before applying retinol, which can make existing issues worse. “Never apply it to areas that are red, puffy, or irritated,” says Ciraldo. You can also try other natural vitamin A ingredients, like rosehip oil, sea fennel extract, seaweed extract, and beta-carotene. They won’t necessarily do the same thing as retinol, but at the very least, they can nourish your skin with similar nutrients.