The Enemy: Free Radicals

If you’re unfamiliar, free radicals are unpaired (and therefore, unbalanced) oxygen atoms that haphazardly seek other atoms to stabilize themselves. They’ll latch onto anything—your skin cells being a ready target—and cause a chain event of damage that leads to premature aging. As their name implies, antioxidants are the “antidote to oxidation” and help combat that damage directly. And Vitamin C is a powerful antioxidant.

Vitamin C: The Skincare Hero We All Deserve

“A topical daily vitamin C serum is one of the best inventions the skincare community has made in regard to slowing down visible skin aging, such as fine lines, wrinkles, and brown spots,” says celebrity esthetician Renée Rouleau. “This is especially true when it’s applied on a daily basis.” Vitamin C also has the benefit of brightening your overall complexion for skin that looks even-toned and radiant. “I usually recommend applying vitamin C serum in the morning under moisturizer and sunscreen, as it can then work to combat exposure to free radicals and ultraviolet light throughout the day,” advises Dr. Steven Mandrea, a board-certified dermatologist and co-founder of Lakeview Dermatology in Chicago.

Why Vitamin C Should Be Paired With Sunscreen

“Combining vitamin C serum and broad-spectrum sunscreens that protect well against UVA rays has been shown to be more effective at neutralizing free radical damage from sun exposure than just using sunscreen alone,” Mandrea says. According to this study from 2013: “Sunscreens block only 55 percent of the free radicals produced by UV exposure…To optimize UV protection, it is important to use sunscreens combined with a topical antioxidant…Under laboratory conditions, it has been shown that application of 10 percent topical vitamin C showed [a] statistical reduction of UVB-induced erythema by 52 percent and sunburn cell formation by 40-60 percent.” In other words, when sunscreen and vitamin C are applied together, their benefits multiply. Just like your favorite duos (Chip and Joanna Gaines or peanut butter and jelly), they’re good alone, but better together.

Try These Vitamin C and Sunscreen Pairings

Skinceuticals is a pioneer of vitamin C product formulation. The brand’s C E Ferulic with 15% L-ascorbic acid ($169, skinceuticals.com) may cost a pretty penny, but it’s a tried-and-true favorite of dermatologists, estheticians, and beauty editors. Pair it with the brand’s award-winning Physical Fusion UV Defense SPF 50 ($36, skinceuticals.com), a broad-spectrum mineral sunscreen. Another noteworthy vitamin C serum is PCA skin C&E Strength Max ($110, amazon.com). It boasts a potent, pure vitamin C and pure vitamin E formula that squeezes out of the tube as a thick cream and transforms into a sheer, almost powder-like substance on your skin. Because of the unique formulation, it pairs beautifully with pretty much any liquid or cream sunscreen. Try it with Supergoop! Unseen Sunscreen SPF 40 ($20, sephora.com), which has a similar texture and doubles as a makeup primer. As the name implies, it’s completely clear, so it works on any skin tone. Vitabrid C¹² FACE Brightening Powder ($68, vitabrid.com) is a powder version of vitamin C that mixes easily with moisturizer formulations. We recommend pairing it with a creamy, hydrating product like Juice Beauty SPF 30 Oil-Free Moisturizer ($34, ulta.com) or Kiehl’s Ultra Facial Cream ($22, kiehls.com). There are also a handful of products that are already pre-mixed. These include The Body Shop’s Vitamin C Glow-Protect Lotion SPF 30 ($23, thebodyshop.com) and Supergoop! PLAY Antioxidant Body Sunscreen Mist SPF 50 ($21, sephora.com). Whatever pairing you choose, vitamin C products are an integral addition to your daily skincare routine, especially when paired with broad-spectrum sunscreen.