Here’s How to Use Vitamin C Serums for the Best Results

Even if you only dabble in skin care, you’ve likely seen vitamin C serum touted as a beneficial beauty product. But what does vitamin C do for your skin, exactly? In short: Vitamin C is a “potent antioxidant” that can potentially help brighten dark spots, aid in smoothing fine lines, and neutralize skin-harming free radicals from the environment, including pollution and U.V. radiation, Sara Hogan, MD, board-certified dermatologist and fellow of the American Academy of Dermatology, tells SELF.

Before you run out and buy the first delightfully orange serum you see, though, there are some important things to consider, as not all vitamin C products are created equal. Depending on the product’s specific formulation and your personal skin needs, vitamin C can even be irritating or finicky in some cases, Angela Lamb, MD, board-certified dermatologist and director of Westside Mount Sinai Dermatology Faculty Practice, tells SELF.

But don’t let that deter you from giving this impressive, science-backed ingredient a try. Keep reading to find out why and how you should incorporate a vitamin C serum into your skin-care routine.

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1. What does vitamin C do for your skin?

What, exactly, does vitamin C do for your skin, you ask? Well, it has the potential to help with a lot of issues, especially when applied topically in serum form. “Vitamin C has a wide range of protective and anti-aging effects for the skin,” Annie Chiu, MD, a board-certified cosmetic and general dermatologist on faculty at Cedars-Sinai Medical Center, tells SELF. “Serums typically offer the highest concentrations of active vitamin C and tend to have better skin penetration compared to other vitamin C products, like creams and cleansers.” Here are a few of the biggies when it comes to benefits:

Vitamin C can help reduce the appearance of fine lines and wrinkles.

That’s because the antioxidant can help your skin produce collagen—a protein that gives your complexion a firmer, bouncier feel, which in turn helps to improve the look of fine lines and wrinkles, Dr. Chiu explains.

Vitamin C can help brighten your skin.

With consistent use, your skin can become more even in tone—and downright glowy!— because vitamin C inhibits the over-production of melanin, the substance in your body that produces pigmentation in your hair, eyes, and skin. Some areas of the skin will create too much melanin which is what leads to hyperpigmentation. This often manifests as darkened skin discoloration, says Dr. Chiu.

Vitamin C can help protect your skin.

Yep, it may help prevent skin damage that can be caused by environmental aggressors, like U.V. rays, pollution, or smoke, among others. “Vitamin C is an antioxidant, which helps fight free radicals (unstable molecules in the body) that age the skin,” says Dr. Chiu. It has some possible healing effects, too. “Vitamin C has anti-inflammatory properties and boosts wound healing by helping cells migrate to the area of the skin injury,” she says.¹

2. What are the possible side effects of vitamin C serum?

The most common side effects of using a vitamin C serum include skin irritation like tingling upon application, redness, and itching, but this mostly happens to “sensitive or reactive skin,” Dr. Chiu says. Always patch test an area of skin before you try any new product, especially a potent one like a serum. Many derms recommend applying a small dollop (a dime-sized amount should do) to your inner arm for a day or two to see how your skin reacts before slathering it all over your face.

Dr. Chiu warns that stronger formulations can sometimes have a low pH, which can be especially irritating for those with dry and/or sensitive skin. To be safe, she recommends starting with a gentler formula at first—one that contains less than 5% vitamin C—and then working your way up, if you’d like. Most people can benefit from going up to 10% once their skin can handle it, and some can go up to 20%, as long as it’s applied only once per day.

3. Is vitamin C good for acne-prone skin?

People with acne can potentially benefit from adding a vitamin C serum to their routines, but there are a few nuances to consider. A 2013 research review in the Indian Journal of Dermatology, Venereology, and Leprology suggests that topical vitamin C can improve acne lesions in up to 77% of patients.²

As for acne scars, it’s good for that, too, thanks to those collagen-boosting and skin-brightening powers that were mentioned earlier. (You’ll just want to avoid any vitamin C formulas that are heavy or pore-clogging like oils or rich creams that often further exacerbate acne.)