Read The Label: All Your Vitamin C Questions Answered

Feel like you need a dictionary every time you look at the ingredient list of a beauty product? Still unsure of the difference between retinol and retinoids? What about the unique benefits of vitamins B, C, and E? Are alpha and beta hydroxy acids the same thing? The skincare aisle can be overwhelming, but you don’t need a PhD in cosmetic chemistry to navigate it. With expert help, The AEDITION is demystifying and simplifying the beauty industry — one label at a time.

If there's one skincare truth it is this: pigmentation, dull skin, and wrinkles are virtually unavoidable. There is, however, a very strong probability that vitamin C can improve the appearance of many of those skin concerns. Found on skincare ingredient labels under names like L-ascorbic acid and tetrahexyldecyl ascorbate, vitamin C is an antioxidant that is widely praised for its ability to brighten skin, lighten pigmentation, and protect against UV damage.

Often associated with citric fruits (oranges and lemons did, after all, help sailors with scurvy at sea), it’s a water-soluble vitamin that is not naturally produced by the body. Instead, it is something we absorb through topical products, supplements, or foods. While vitamin C supplements are known for their immune-boosting powers (look no further than COVID-19 patients being treated with large doses of the natural remedy), an orange a day will not keep the wrinkles away. Instead, you'll need a well-formulated skincare product with vitamin C.

What Is Vitamin C?

“Vitamin C is an antioxidant that has a number of proven benefits for the skin,” says board certified cosmetic dermatologist Sejal Shah, MD, of SmarterSkin Dermatology in New York City. “It is known for anti-aging, brightening the complexion, evening out skin tone, preventing free radical damage, and restoring and regenerating the skin.”

Like its fellow antioxidants, vitamin C defends against environmental stressors (think: free radical damage), in addition to improving the appearance of the skin. “It protects the skin from any of the bad elements you come into contact with on a daily basis, like UV rays or air pollution,” says Bella Schneider, clinical skincare pioneer and founder of Bella Schneider Beauty and the La Bella Spas in California. “It also evens out and brightens skin tone, texture, fine lines, acne scars – you name it.”

Benefits of Vitamin C in Skincare

While there is no silver bullet in skincare, vitamin C certainly has a lot to offer thanks to its preventative and corrective benefits.

• It’s Anti-Aging: “It decreases the activity of metalloproteins (MMPs), which are enzymes that break down collagen,” says board certified cosmetic dermatologist Julie Russak, MD, of the Russak Dermatology Clinic in Manhattan. This helps improve skin texture and decrease the appearance of fine lines. And, because the efficacious formulation has acidic properties, Schneider explains that a topical vitamin C “encourages skin tissue to heal quickly by turbo-charging the production of collagen and elastin, which are key elements to keeping skin plump and youthful-looking.”

• It’s Protective: Because it is a potent antioxidant, vitamin C is great for “decreasing the effects of UV and environmental damage,” Dr. Russak says. The oxidative damage caused by the sun leads to premature aging and has potential skin cancer dangers that vitamin C aids in preventing.

• It Evens Skin Tone: “Vitamin C inhibits melanin synthesis and has anti-inflammatory activity,” Dr. Shah shares. As a result, topical application helps brighten and lighten hyperpigmentation and skin discoloration concerns such as scars, dark spots, and stretch marks.

Finding the Right Vitamin C Product

Despite its workhorse classification, vitamin C is actually a very difficult ingredient to formulate with. The best vitamin C products are usually housed in dark, airtight environments, though technological advancements have been made to better stabilize the antioxidant. To ensure you are using the best the market has to offer, our experts recommend keeping the following points in mind:

• The Name: L-ascorbic acid is the most active and studied form of vitamin C, but that doesn’t mean it is for everyone. “It is very unstable and has poor penetrability into the skin,” Dr. Russak says. “To improve penetration, it has to be at a very specific pH (below 3.5) and at a high enough concentration to have a meaningful amount to penetrate the skin.” A more stable alternative can be found in tetrahexyldecyl (THD) ascorbate, which is “a chemically modified form of L-ascorbic acid that gets converted into an active form intracellularly,” Dr. Russak explains. The result? It is more easily absorbed by the skin. Schneider warns that those with extremely sensitive skin should look for milder and less acidic forms of vitamin C like magnesium ascorbyl phosphate for a gentler experience.

• The Form: “Serums keep vitamin C the most stable and have the best delivery system,” Dr. Russak shares. “Creams are good for more sensitive skin because they tend to have more ingredients that decrease irritation.” Gel-based formulas, however, may be a bit too aggravating for most. “Gels have more alcohol-based content and are more irritating when combined with ascorbic acid,” she adds.

• The Package: Because vitamin C oxidizes on contact to the air and exposure to light can degrade its benefits, Schneider recommends formulations in airtight, dark or opaque glass jars or vials for longer term potency and stabilization.

When to Use Vitamin C

Unlike certain active ingredients that are only safe to use in the morning or at night, vitamin C can be incorporated into both morning and evening skincare routines. Here’s how to make it work for you:

• A.M. Usage: “I typically recommend using it as a serum underneath moisturizer/SPF in the morning, daily,” says Dr. Shah. Schneider agrees, adding that “while vitamin C does help protect against free radicals, it’s not a sunscreen replacement.” You still need a SPF for sun protection.
• P.M. Usage: When adding it to your evening routine, be mindful of other nighttime ingredients, such as bedtime favorite vitamin A. “For sensitive skin, using a strong retinol can make the skin very sensitive to vitamin C,” Dr. Russak warns. “Also, if using any strong acid peels before applying a vitamin C serum, the skin can become very irritated.”

So, what actives play well with vitamin C? “Ingredients such as vitamin E and ferulic acid help boost a vitamin C serum’s potential,” Schneider says. And, if you are prone to skin sensitivity, ingredients like niacinamide can help to temper the potent antioxidant. “Lipophilic formulations that tend to have anti-inflammatory ingredients or additives, such as niacinamide, are better for sensitive skin,” Dr. Russak explains. Some of our favorite hybrid formulas include the SkinCeuticals CE Feurlic and Saint Jane Beauty C-Drops. The latter combines vitamin C with 500 milligrams of full-spectrum CBD.

Best Candidates for Vitamin C

“I tell all my clients to use vitamin C daily and never stop,” Schneider shares. “It doesn’t matter whether they’re 18 or 80.” Just remember to not get overzealous if you have sensitive skin. As with any new ingredient or product, take your time introducing it into your routine.

Dr. Shah recommends that those with sensitive or reactive skin should “test the product on your skin first and gradually introduce it into your skin regimen.” While it targets skin concerns such as fine lines and pigmentation, she adds that the anti-inflammatory properties “may even help conditions such as rosacea and acne.”

The Takeaway

Vitamin C benefits the dermis with its skin-brightening attributes, collagen-boosting elements, and toning qualities. It can help with everything from correcting hyperpigmentation to preventing UV damage, but it’s important to find the right formula. Fickle when exposed to light and air, the powerhouse antioxidant tends to work best in serum form — combined with a moisturizer and SPF during the day and non-retinol products at night.