Skin Care Blogs

Everything You Need to Know About Vitamin C, The Most Underrated Ingredient in Skincare

Vitamin C is the organic substance that gives orange juice its superpowers and amps up your immune system when you feel a cold coming on. So what’s up with slathering it on your face? We asked board-certified dermatologist Dr. Ashley Magovern, MD, medical director of Dermstore

What Does Vitamin C do for Your Skin? 

“Vitamin C is an important building block for collagen synthesis in your skin,” Dr. Magovern says. If you missed that bio lesson, collagen is a structural protein that makes up the skin itself and contributes to its firmness and thickness, she explains. As we age, we lose collagen, which contributes to laxity and results in fine wrinkles. “Encouraging the skin to make more collagen is the cornerstone of everything dermatologists do to combat the signs of aging,” she says. “And the products you use at home make a huge difference.” 

Enter, vitamin C, a common skin serum ingredient that builds collagen in two ways: As a natural antioxidant, it combats the free radical damage that results from everyday exposure to the sun’s UV rays and environmental pollutants by donating electrons to neutralize the free radicals that cause oxidative stress. In turn, this reduces inflammation and reorganizes the skin structure to mimic younger skin, which helps build up lost collagen. And as if vitamin C couldn’t get any more impressive, the stuff actually stimulates collagen synthesis directly, as well. 

“Everyone should be on vitamin C,” Dr. Magovern says. “It has so many benefits backed by scientific evidence.”  

Jump on the bandwagon, and pretty soon, you may see the perks of skin repair and collagen production when you look in the mirror. Your skin may appear brighter and more even with less noticeable dark spots; less inflamed; and tighter.  

How to Use Vitamin C on Your Skin 

In a multi-step skincare routine, Dr. Magovern recommends applying the thinnest products first and progressing to the thickest. Vitamin C serum typically falls into the former category. “I love using serum under moisturizer,” she says—particularly when introducing a new serum to the skin. After all, if your skin is dry or inflamed, any new product can cause some irritation.  

When to Use Vitamin C Serums

Because vitamin C reverses some of the oxidative stress and free radical damage that takes place during the day, it makes sense to apply it at night when skin regenerates, according to Dr. Magovern. “I like to give the skin an extra push by applying a serum that contains vitamin C.”  

That said, there’s no downside to applying vitamin C in the morning, instead, or even twice a day. “I’m OK with whenever you want to put it on,” she says.  

If you opt for the am, don’t confuse the sun damage-reversing benefits of vitamin C with skin protection. “Vitamin C combats oxidative stress and free radical damage that leads to the breakdown of collagen, but it doesn’t protect your skin from UV rays and further damage,” Dr. Magovern warns. In other words, even a generous application of vitamin C serum won’t take the place of a good old SPF, which should be applied after serum and moisturizer but before makeup.

Potential Side Effects of Using Vitamin C

Vitamin C is well-tolerated by most skin types with no known risks for pregnant or breastfeeding women. If you do happen to notice stinging, redness, or dryness after applying a vitamin C serum, layering on a moisturizer should nip these side effects in the bud. And if you’re nervous? Begin with a serum that contains a lower concentration of vitamin C—think 5 to 10 percent rather than the ideal 15 to 20 percent—particularly around the eyes where skin can be more sensitive. 

Should you expect your skin to act up in response to a new vitamin C treatment? “No, not necessarily,” says Dr. Magovern. “Any product you put on skin that’s dry or inflammed can cause a little irritation, but hydrating the skin when using active ingredients can help the skin accept the product.” She recommends layering on moisturizer after vitamin C serum for this reason.

If your skin is acne-prone, you don’t have to worry about vitamin C making things worse. “It doesn’t clog your pores and it can actually improve acne by reducing irritation that can compromise the skin barrier and lead to breakouts,” Dr. Magovern says.  

That said, vitamin C can be a vehicle for other ingredients that do cause breakouts or don’t agree with sensitive skin, so read product labels and ask your dermatologist for recommendations if you’re concerned. Otherwise, slather away. 



Elizabeth Narins

Elizabeth Narins is a freelance writer, editor, and content/social media strategist based in Brooklyn, New York. The former senior director of digital and social content at WW (formerly Weight Watchers), she has held staff positions at Women's Health and Cosmopolitan, and is no stranger to a beauty closet. Elizabeth's work (and too many photos of her curly-haired toddler) can be found on Instagram @ejnarins.