Why Vitamin C Is One of the Most Important Steps in Any Skin-Care Routine

Rebecca Dancer
·7 min read

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The benefits of vitamin C serums are vast. Uneven skin tone, sun damage, rough texture, fine lines, acne scars, general dullness—you can name just about any common complexion concern and there's a good chance that vitamin C (and the skin-care formulations it's featured in) is a recommended treatment. And if Allure's annual Readers' Choice Awards survey is any indication, it's one of the most in-demand ingredients in skin care today. But how exactly does it work on the skin? Are the brighter, smoother results due to the same nutrients found in the orange juice you drink when you have a cold?

Given that interest in the ingredient is seemingly at an all-time high, we felt a deeper dive into the wonders of vitamin C was warranted. We consulted the experts to learn all about the effects of vitamin C (and what makes it such a sought-after skin-care ingredient), as well as the best ways to reap its many benefits.

Meet the experts:

  • Patricia Wexler, MD, a board-certified dermatologist based in New York City.

  • Joshua Zeichner, MD, a board-certified dermatologist based in New York City.

  • Kristina Goldenberg, MD, a board-certified dermatologist based in New York City.

  • Marie Jhin, MD, a board-certified dermatologist based in San Carlos, California.

In this story:

First off, what is vitamin C?

As far as your skin is concerned, vitamin C is "a potent antioxidant that can neutralize free radicals," explains Patricia Wexler, MD, a board-certified dermatologist based in New York City. "Because of its antioxidant properties, vitamin C aids in your skin's natural regeneration process, which helps your body repair damaged skin cells."

So, in the same way that consuming antioxidant-rich foods (including, yep, vitamin C-rich orange juice) aids your body in fighting off free radicals, topical antioxidants do the same for your skin by neutralizing the production of highly reactive molecules called free radicals, which can be trigged by everyday aggressors like UV damage and air pollution. In other words, antioxidants help keep our body and our skin cells healthy—and looking that way.

This free-radical-fighting power isn't just important for helping to keep signs of premature aging at bay. In neutralizing these free radicals, vitamin C may also help protect skin from precancerous changes caused by UV exposure, Joshua Zeichner, MD, a board-certified dermatologist based in New York City, previously told Allure.

How else does vitamin C benefit the skin?

Amazingly, vitamin C's skin-saving benefits aren't only attributed to its antioxidant properties. It has plenty of other skin-healing properties that make it an excellent choice for anyone in pursuit of happy, healthy skin. For one, studies have shown that when vitamin C is used topically, it can help accelerate the skin's production of collagen and elastin. Remember: Collagen and elastin are both naturally occurring protein fibers that help keep skin plump and firm. So, in helping to promote collagen production, topical vitamin C can help prevent signs aging of the skin, including fine lines and lack of elasticity.

Another cool thing about the ingredient: As Allure has previously reported, It inhibits the action of the enzyme tyrosinase — the main enzyme responsible for the conversion of tyrosine into melanin — and therefore decreases melanin formation. And it's melanin formation that causes skin discoloration like dark spots and hyperpigmentation, Dr. Wexler explains. With continued topical use, vitamin C can help prevent dark spots from forming in the first place—and can also reactively treat the ones you might already have acquired.

How can you add vitamin C to your daily skin-care routine?

"The key is not the vehicle that vitamin C comes in, but the form of vitamin C that is being applied," explains Kristina Goldenberg, MD, a board-certified dermatologist based in New York City. The term to look for is ascorbic acid (also known as L-ascorbic acid), which is the most stable and effective form of vitamin C in skin care.

That said, all three dermatologists agree that the best type of vitamin C skin-care product to use is serum, because “serums are more effective than creams or toners” since the thinner texture penetrates the skin more easily, says Dr. Wexler. (That said, there are some of the market that are more lotion-like and could be a good choice for those with drier skin types.) Moreover, adding vitamin E into the mix is like a one-two punch of skin-saving goodness.

"Pure ascorbic acid has consistently been proven to be the most effective at penetrating the skin barrier," Dr. Wexler says. "Vitamin C effectiveness [also] increases when combined with other antioxidants, such as vitamin E. Together, they can double protection against free-radical damage."

This is why you'll very often find the two antioxidants formulated together in serums, such as the legendary and Best of Beauty Award-winning SkinCeuticals C E Ferulic, Naturium Vitamin C Complex Serum, Paula's Choice C15 Super Booster, and L'Oréal Paris Revitalift 12% Derm-Grade Vitamin C, E, Salicylic Acid Serum.

SkinCeuticals C E Ferulic

$182.00, Dermstore

Naturium Vitamin C Complex Serum

$21.00, Amazon

Paula's Choice C15 Super Booster

$55.00, Amazon

L'Oréal Paris Revitalift Vitamin C Vitamin E Salicylic Acid Serum

$30.00, Amazon

You'll also notice that none of these bottles are clear—and that's on purpose. Like retinol, vitamin C breaks down when it's exposed to light or air, so dark glass bottles help maintain its stability (and therefore efficacy). If a vitamin C-based product changes color—often from yellow or orange to brown—it can be a signal that the vitamin is breaking down and therefore not as effective.

If you're new to using the ingredient on your skin, dermatologists advise starting slowly, using just a few drops for a single application every few days. If your skin seems to tolerate it, you can work your way up to using it each morning (which is when you skin will benefit most from its free-radical fighting power) and evening (if you're after a collagen boost). As a general rule, serums should be layered underneath your moisturizer and SPF.

Typically, 5% serums are gentle enough for sensitive skin, and you can go all the way up to 20%, which will work more quickly to brighten and improve skin pigmentation. Other forms of vitamin C you may come across in skin-care products include tetrahexyldecyl ascorbate, magnesium ascorbyl phosphate, and methylsilanol ascorbate.

Who should avoid vitamin C?

"Those with sensitive skin may have allergies or redness from vitamin C," Dr. Goldenberg says. If you tend to have sensitive skin, she recommends starting with a lower concentration and also “trying a test area first to make sure that no allergy exists.”

To avoid side effects, you might also want to tread carefully if you're already using certain active ingredients. Benzoyl peroxide, which is often used to treat acne, does not play well with vitamin C—it causes the ingredient to degrade, rendering it useless. And when paired with vitamin C, alpha hydroxy acids (AHAs) can cause irritation, so consider using the former in the morning and the latter at night—as Marie Jhin, MD, a board-certified dermatologist based in San Carlos, California, has told Allure. You can apply the same method with retinol (apply it at night, then use vitamin C in the morning), or if you want a double dose of both, wait at least 30 minutes before applying retinol over vitamin C, says Dr. Jhin.

Now shop some of our favorite vitamin C products:

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Originally Appeared on Allure