Derms Say to Look for These 4 Things Before Buying a Vitamin C Serum

We’ve learned the hard way: What’s effective for someone else’s skin—read: the latest influencer you swiped-up for—might lead to a less-than-ideal result on your own. Rather than investing in a vitamin C serum because of how it performed on someone else’s complexion, Miami dermatologist Dr. Deborah Longwill suggests shopping based on your specific skin needs for the best glow-boosting results. Ahead, four steps to finding the perfect vitamin C for your skin.

Understand the Numbers Game

“In theory, anyone can use and can benefit from vitamin C or one of its derivates,” says Miami dermatologist Annie Gonzalez, MD. “Better-tolerated forms usually contain a concentration of between 10 and 15%, although some very sensitive skin types may have to start off with lower concentrations.”

Shop by Skin Type

“If you have dry skin, I would recommend looking for vitamin C products that contain moisturizing ingredients like hyaluronic acid,” says Dr. Longwill, noting that a lower concentration of vitamin C might also be beneficial. Along with brightening vitamin C, Dr. Barbara Sturm’s The Good C Serum ($145) contains hydrating hyaluronic acid and glycerin to brighten and quench thirsty skin.

For sensitive skin, Dr. Gonzalez notes that generally, THC tetrahexyldecyl ascorbate, a derivative of vitamin C, has been found to be better tolerated by finicky skin types than traditional vitamin C. “I find [it] is more skin-friendly in general and may even have deeper penetration than its hero counterpart, L-ascorbic acid (LAA) due to the pH of the formula being a little higher compared to LAA,” she says. Another sensitive-skin approved derivative: ascorbyl glucoside, found in Avène A-OXitive Antioxidant Defense Serum ($44).

For oily skin, Dr. Longwill suggests a formula that contains ascorbic acid. While shopping, Dr. Gonzalez also says to be mindful of one particular ingredient. “Vitamin E—aka tocopherol—is often added for greater stability and antioxidant power, but can be problematic for oily patients,” she says, noting that oily patients should also avoid formulas that contain oil in its base.” Her go-to recommendation: SkinBetter Science Alto Defense Serum ($155).

For blemish-prone skin, opting for a vitamin C that also contains salicylic acid—we’re partial to La Roche-Posay 10% Pure Vitamin C Serum ($40)—can help keep breakouts at bay while maintaining that glow.

Pairing Plus

While claims of pure vitamin C might seem more potent and thus worth an investment, Dr. Longwill says that’s not always the case. “Vitamin C is an antioxidant and works best with complementing antioxidants such as vitamin E and ferulic acid. These antioxidants will boost the vitamin C molecules.” Dermatologist-loved SkinCeuticals CE Ferulic ($166) put the efficacious duo on the map; Fan-favorite MaeLove The Glow Maker ($28) also perfects the pair.  

Packaging Matters

Once you find your perfect formula, Dr. Longwill says its packaging is just as important as the juice inside. “Vitamin C can lose its antioxidant properties when exposed to air, light and other chemicals,” she says. “To prevent your products from oxidizing make sure the packaging is air tight.”