For years, the topical antioxidant big dog has been vitamin C. And for good reason: Products containing it often flaunt enticingly bright and sunny packaging, and the sensorial experience of rubbing it into your skin is undeniably luxurious.

But most importantly, vitamin C is well-studied: It has a robust library of scientific literature dating back to the 1990s, and that evidence has proven time and again that the ingredient can effectively help you achieve a brighter, younger-looking complexion, especially when used with other skincare ingredients proven to work.

“Vitamin C remains one of the top skincare ingredients because it delivers multiple benefits in a single ingredient,” explains Marisa Plescia, president of the Society of Cosmetic Chemists and founder of FemChem Beauty. “It not only functions as a potent antioxidant for boosting the skin’s natural defense, but it also supports collagen synthesis and helps reduce the appearance of hyperpigmentation.”

Meet the experts: Marisa Plescia is the president of the Society of Cosmetic Chemists and founder of FemChem Beauty, a cosmetic chemistry consulting company. Perry Romanowski is the vice president of the Society for Cosmetic Chemists and vice president of Element 44, a cosmetic formulating consulting company. Ava Shamban, MD, FAAD, is a board-certified dermatologist and founder of Los Angeles–based practice Ava MD. Erum Ilyas, MD, FAAD, is a board-certified dermatologist at Schweiger Dermatology in Pennsylvania.

That said, vitamin C is not without its shortcomings, Plescia says. Namely, its instability in formulations can potentially render many vitamin C products useless. Given such a major pitfall, you might be wondering whether this ingredient truly deserves its spot on beauty shelves across the globe.

To get to the bottom of the answer, Women’s Health spoke with cosmetic chemists and dermatologists to break down everything they want you to know about vitamin C—including its benefits for the skin, the downsides of using it, and how it stacks up against other topical antioxidants on the market.

What, exactly, is vitamin C?

Vitamin C is an antioxidant, which means it helps neutralize free radicals, or unstable molecules, that are generated by environmental stressors such as UV rays and pollution and attack and damage skin cells. As such, you can find the ingredient in serums, skin brightening products, face moisturizers, under-eye skincare, and face masks, experts say.

The vitamin occurs in nature—you can find it in foods such as citrus fruit, bell peppers and other produce—but the variations we use in products are generally made synthetically in labs and purified for cosmetic use, experts say.

The most commonly used and most thoroughly researched version of vitamin C in skincare is called L-ascorbic acid. It’s considered the purest, most biologically active form of the ingredient, experts say. However, frustrated formulators quickly learned that this version is difficult to keep stable in products because its prone to degradation when exposed to water, oxygen, and light. In response to these challenges, “the industry did what it always does: It created more versions” of the ingredient, says Perry Romanowski, vice president of the Society for Cosmetic Chemists and vice president of Element 44, a cosmetic formulating consulting company.

In an attempt to strike the perfect balance of stability, efficacy, skin compatibility, and shelf-life, formulators developed various forms of vitamin C that you’ll find on the ingredients list of your products. Common examples include sodium ascorbyl phosphate, magnesium ascorbyl phosphate, ascorbyl glucoside, ethyl ascorbic acid and tetrahexyldecyl ascorbate, Romanowski adds.

What are the benefits of vitamin C for the skin?

When formulated well, vitamin C is a biological multitasker that can be a power player for both skin tone and texture, especially when used daily, says Ava Shamban, MD, FAAD, a board-certified dermatologist and founder of Los Angeles–based practice Ava MD. For instance, by protecting your skin from the sun’s ultraviolet rays, it helps prevent collagen—a protein responsible for keeping skin firm and bouncy—from breaking down over time. It can also help boost its production, she says. This, in turn, delays the onset of signs of aging such as sunspots, fine lines, wrinkles, and inelasticity.

Now don’t get it twisted, vitamin C isn’t a sunscreen in and of itself, Romanowski adds, so it’s still important to wear your SPF every single day. But vitamin C can complement sunscreen by further reducing oxidative stress from ultraviolet radiation and pollution exposure, he says. “It functions as a defense mechanism,” Dr. Shamban adds.

Beyond that, vitamin C is also known to inhibit the activity of a pigment-producing enzyme called tyrosinase, allowing the ingredient to brighten the skin, fade dark spots, and create a brighter, more even complexion, Dr. Shamban says. And another plus: Vitamin C works synergistically with other skincare actives, enhancing the effectiveness of other ingredients such as vitamin E, ferulic acid, and sunscreen, experts say.

Given the long list of perks the ingredient can offer your skin, it’s no surprise that there’s an overabundance of vitamin C products on the market. Here are a few that areWomen’s Health approved:

Vitamin C Products to Try

Best for Aging Skin

La Roche-Posay Pure 12% Vitamin C Serum

If you’re looking to turn back the clock by fading wrinkles, boosting radiance, and achieving softer, smoother skin, give this serum a whirl. Other than 12% L-ascorbic acid, this serum includes salicylic acid to clear pores, and hyaluronic acid to offer long-lasting hydration.

Best for Dull Skin

SkinMedica Vitamin C+E Complex

This gel product combines both vitamin C (in the form of tetrahexyldecyl ascorbate, a more stable version of the vitamin) as well as vitamin E to give you brighter, more youthful-looking skin. It’s formulated for all skin types, and is small enough to be TSA-friendly.

Best for Dry Skin

Olay Regenerist Vitamin C Face Moisturizer Cream

This lightweight, refreshing moisturizer boasts vitamin C in the form of 3-O-Ethyl ascorbic acid, a highly stable version of the ingredient, alongside other powerhouses like glycerin and niacinamide. Plus, it’s citrus-scented, making the sensorial experience just as enjoyable as the skin-rejuvenation benefits.

What are the pitfalls?

Vitamin C’s primary challenge lies in its lack of stability in cosmetic formulations. It quickly oxidizes when exposed to oxygen, light, heat, or metal contaminants, Plescia says, and once the integrity of the ingredient is compromised, its efficacy drops dramatically.

Oftentimes, a vitamin C serum is clear or a pale yellow color when fresh. It’ll also have a pretty benign scent that’s either neutral or slightly metallic. But when exposed to the elements after opening, the serum may turn a darker yellow, orange or even a brown color instead, Romanowski says. It’ll also probably begin to smell differently—all signs that your product has turned rancid.

Since vitamin C is so finicky, storing products containing it with more intention than other ingredients in your routine is paramount: Airtight containers are a must, and dark, cool environments are preferred to reduce the risk of oxidation, experts say. And as a general rule of thumb, toss vitamin C products three to six months after opening it: Even the best formulations have short shelf lives due to the ingredients inherent instability, Romanowski says.

Another downside is the fact that vitamin C can anger the skin when used in higher concentrations: Cosmetic formulas with vitamin C in concentrations over 20 percent tend to be particularly irritating, according to one study in the Journal of Clinical And Aesthetic Dermatology.

Plus, L-ascorbic acid needs to be formulated with a very low, or acidic, pH in order to benefit the skin, research suggests. And when a substance disrupts our skin’s natural pH (which is closer to neutral, rather than highly basic or acidic) the skin barrier can become compromised—leading to excess sensitivity and irritation, Women’s Health previously reported. This is especially true in patients with sensitivity, rosacea, or eczema-prone skin, adds Erum Ilyas, MD, FAAD, a board-certified dermatologist at Schweiger Dermatology in Pennsylvania.

And as previously mentioned, cosmetic chemists developed other versions of vitamin C in an attempt to resolve the stability problem. Even though those derivates are indeed more stable and gentler on the skin, they don’t always work as well as plain ol’ L-ascorbic acid, Romanowski says. These alternatives must undergo chemical conversions on the skin before they can become the active form of the ingredient and work their magic. “And how well that happens is not always clear,” Romanowski explains.

As such, its possible to find yourself stuck between a rock and a hard place when using vitamin C: You may use a product that works but carries a higher risk of irritation, or you may use a gentler product that doesn’t provide your skin much benefit.

So, how does Vitamin C stack up against other antioxidants?

Compared to newer, emerging antioxidants in skincare like glutathione, melatonin, ferulic acid, and pterostilbene, vitamin C has a serious head-start in the metaphorical scientific research race. In fact, there are so many studies on the efficacy of vitamin C that recent research has moved away from testing whether the ingredient works and instead focuses on how to better optimize it in topical formulations, Plescia says. Others are still catching up. For this reason, vitamin C remains the antioxidant best supported by current research, despite its drawbacks.

Nevertheless, experts agree there are certain antioxidants worth incorporating into your routine as well. They include:

• Niacinamide: Also known as vitamin B3, niacinamide is much easier to formulate with compared to vitamin C, Romanowski says. But more importantly, there is substantial evidence to support the ingredient’s efficacy for a variety of cosmetic and skin health concerns such as inflammation, pore size, excess oil production, and dark spots, Women’s Health previously reported. It’s also used in topical treatments for acne, melasma, eczema, rosacea, psoriasis, wrinkles, skin laxity, texture changes, sensitivity, and pigmentation, as well as increasing ceramide and fatty acid production in the skin to strengthening the skin barrier. As such, this ingredient may be a better choice than vitamin C for more sensitive skin types.
• Ectoin: Recent research demonstrates this ingredient’s effectiveness against photodamage, Plescia says, making it a tool to combat premature skin aging caused by sun exposure. It’s also thought to help repair the skin barrier in folks with inflammatory skin conditions, and it can offer deep hydration to dry skin.
• Ferulic acid: This plant-based antioxidant is often found in formulas alongside vitamin C to help ward off oxidation, Dr. Shamban says. “Ferulic acid is a great booster, [increasing] the efficacy of C and E while simultaneously acting as a strong agent of protection against UV rays and sun damage.”
• Vitamin E: Like niacinamide, this vitamin earns a mention because it’s easier to formulate with, especially in oil-based formulas, Romanowski says. The ingredient, also called tocopherol, is a potent antioxidant that’s actually produced naturally in our skin, Women’s Health previously reported. It’s often put in formulas alongside vitamin C because studies suggest both vitamins work synergistically to protect skin from elements in the environment. Vitamin E is also an emollient, meaning it’s good for moisturizing and softening the skin.

If you’re looking to supplement your skincare routine with antioxidants other than vitamin C, here are a few worth giving a try:

The Best Antioxidant Skincare for Better Skin

Best for Dry Skin

The Ordinary Rice Lipids + Ectoin Microemulsion

This ultra-light moisturizer is formulated to sooth and hydrate dry skin for up to 24 hours. It contains ectoin, a formidable antioxidant that combats photoaging and skin inflammation, alongside rice lipids, and jojoba oil.

Best for Dark Spots

La Roche-Posay Mela B3 Serum

This serum features a patented pigment-reducing complex called Melasyl, which helps to fade stubborn areas of discoloration. Also in there: 10 percent niacinamide to further reduce hyperpigmentation, and encourage radiance.

Best for Oily Skin

Naturium Niacinamide Face Serum 12% Plus Zinc 2%

Alongside leveraging niacinamide’s ability to fade dark spots, this serum includes zinc PCA to control oil production in the skin. The formula work to reduce signs of aging, the appearance of pores, and promote a more even complexion.

The bottom line: Vitamin C is still the winner.

The skincare industry will always chase the next big thing, and some of those things are genuinely worth watching. But when it comes to antioxidants, vitamin C has earned its cult status, and the research still backs it up.

That doesn’t mean other antioxidants aren’t worth using: Ingredients like niacinamide genuinely give vitamin C a run for its money given its own established body of research. But if you prefer to rely on ingredients supported with the longest-standing, most robust scientific evidence to rejuvenate your skin, vitamin C remains your best bet.

Wendy Rose Gould is a veteran lifestyle journalist who’s covered topics around skin, hair, health, and wellness for over 15 years. Her reporting has appeared in Real Simple, Well+Good, Allure, Martha Stewart, Verywell Mind, and other outlets. Whether on the ground at NYFW or talking trends with industry experts, she’s always excited to report on the next new thing.  

Katie Mogg is the beauty editorial assistant at Women’s Health. Since starting college at Northeastern University in 2020, her bylines have appeared in The New York Times, The Wall Street Journal, NBC News and The Boston Globe. She strives to help readers lead happier and healthier lives through science-backed stories that explain how to care for hair, skin and nails. When she’s not working, Katie enjoys live music, strolling through Central Park, planning her next beach getaway, and sharing hotpot with friends.