We independently evaluate all recommended products and services. If you click on links we provide, we may receive compensation. Learn more. Beauty Skincare The 17 Best Vitamin C Serums to Brighten Skin And Boost Your Glow, Tested & Reviewed Dull-looking skin? We don't know her. By Emily Orofino Emily Orofino Emily Orofino has over a decade of experience working in beauty. You can find her work on sites such as Harper’s Bazaar, Byrdie, Editorialist, POPSUGAR, & RealSelf. She has also lent her expertise to marketing departments & product development teams of some of the industry’s most prestigious brands. InStyle's editorial guidelines Updated on April 26, 2024 @ 05:20PM In This Article Expand Jump to a Section Our top picks Reviews What to Keep in Mind Your Questions, Answered Why Shop With Us InStyle / Jessica Juliao You’ll hear it from pretty much any dermatologist: If you only use three skincare products, they should be sunscreen, retinol, and vitamin C. But to really soak in all the rewards this powerhouse vitamin has to offer, you can’t just consume it—you have to apply it topically to see its benefits play out on your skin. “Vitamin C is one of very few ingredients that is truly multifaceted,” says Dr. David Kim, a board-certified dermatologist at Idriss Dermatology in New York City. "It can brighten your skin, boost collagen production, and help remove free radicals." You’ll find plenty of vitamin C devotees faithfully applying the ingredient every morning to their skin to protect it against the ravages of UV damage and air pollution, but there are still many skincare lovers that have yet to add vitamin C to their regimen. And we get it: “Vitamin C can be irritating to the skin, so finding the right vitamin C for your skin can be challenging,” says Dr. Kim. And when you’re trying to transform your skin for the better, who wants to test products that may end up making your complexion worse? We tested 44 popular and top-rated vitamin C serums for six weeks, but first we researched ingredients, reviewed medical journals and recent studies for the most current information available, and relied on four board-certified dermatologists, plastic surgeons, nurse practitioners, and celebrity aestheticians, to help us vet formulas and the ingredients within. We evaluated each product across four categories: Easy integration within our skincare routine, level of wearability, noting any annoyances, like smelly formulas or slimy textures, product packaging, and the overall results it gave us. Our editorial team tallied the scores, and these are the vitamin C serums that excelled in each category. Our Top Picks Best Overall: SkinCeuticals C E Ferulic at Dermstore ($182) Jump to Review Best Affordable: L'Oreal Paris Revitalift Vitamin C Face Serum at Target ($27) Jump to Review Best Dermatologist-Recommended: SkinBetter Science Alto Advanced Defense and Repair Serum at Skinbetter.com (See Price) Jump to Review Best for Dark Spots: Comfort Zone Skin Regimen 15.0 Vitamin C Booster at Comfortzoneskin.com (See Price) Jump to Review Best Anti-Aging: RoC Daily Serum at Amazon ($25) Jump to Review Best Fast-Acting: HoliFrog Sunnyside C Glow Serum at Dermstore ($48) Jump to Review Best for Hyperpigmentation: BeautyStat Universal C Skin Refiner Vitamin C Serum + SPF 50 Mineral Sunscreen at Nordstrom ($26) Jump to Review Best for Daytime Use: Drunk Elephant C-Firma Fresh Vitamin C Day Serum at Ulta ($79) Jump to Review Best for Acne-Prone Skin: TruSkin Vitamin C Facial Serum at Amazon ($22) Jump to Review Best Hydrating: Biossance Squalane + Vitamin C Rose Oil at Sephora ($74) Jump to Review Best Overall SkinCeuticals C E Ferulic Bluemercury View On Dermstore $182 View On Skinstore.com $272 View On Skinceuticals.com $182 What We Love: This product is seriously hyped—and it actually lives up to it.What We Don’t Love: Weirdly enough, this smells like boiled hot dog water (there’s no added fragrance), but the aroma fades as soon as it’s applied. This SkinCeuticals formula is quite frequently found at the top of roundups of “the best vitamin C serums,” which may make you suspicious—is it actually that good, or is it a conspiracy by Big Skincare? But this is one of those rare instances where the formula truly delivers. The product legitimately left our skin glowing, not just because it made it more even in tone, but also in texture, smoothing fine lines and wrinkles and making our complexion touchably soft. The antioxidant-rich formula is very fluid (like water) so it quickly absorbs into the skin. However, be aware that as it sinks in, you’ll be treated to the serum’s only frustrating feature—its aroma. No joke, it quite literally smells like boiled hot dog water, which isn’t particularly pleasant, but does fade very quickly. Formula: Water-like serum | Concentration: 15%｜Key Ingredients: Vitamin C, vitamin E, ferulic acid｜Fragrance-Free: Technically, yes｜Usage: In the morning｜Size: 1 oz Best Affordable L'Oreal Paris Revitalift Vitamin C Face Serum Target View On Target $27 View On Walgreens $36 View On Lorealparisusa.com What We Love: The innovative metal tube packaging allows you to enjoy every last drop while preserving the integrity of the vitamin C inside.What We Don’t Love: The formula has a thick, paste-like consistency that can be tricky to spread (but don’t fret, it melts into the skin relatively quickly to give the skin a matte finish). It’s not always the easiest task to find a skincare product that’s both effective and budget-friendly, so we were thrilled by this formula from L’Oréal Paris. We were actually shocked by how quickly it made our skin look firmer, brighter, and more rejuvenated—in just a few days—and felt like we needed to wear makeup less frequently as a result. It’s also packaged in a sustainable tube that helps keep the vitamin C inside stable and allows you to squirt out every last bit. If you prefer lightweight serums, be aware that this one feels a bit heavier, even thick, which makes it a little difficult to massage into the skin. However, once you’ve applied, the formula gives your skin a silky, matte finish that makes it a great makeup priming step (or just helps smooth the look of fine lines and pores). Formula: Thick serum | Concentration: 10 percent｜Key Ingredients: Vitamin C, glycerin, hyaluronic acid｜Fragrance-Free: Yes｜Usage: Twice daily｜Size: 1.01 oz InStyle / Samantha Jones Best Dermatologist-Recommended SkinBetter Science Alto Advanced Defense and Repair Serum SkinBetter View On Skinbetter.com What We Love: This formula is seriously packed with antioxidants to deliver dramatically visible results in just four weeks—and the packaging keeps the formula stable.What We Don’t Love: Be careful if you apply it closely to your brows or hairline—it can leave a yellow residue behind. We’re big fans of SkinBetter Science products—which are formulated with the guidance of dermatologists and facial plastic surgeons—and that includes this powerhouse of an antioxidant serum. A gentle form of vitamin C, tetrahexyldecyl ascorbate (THD) is one of the star ingredients, but it’s supported by more than 15 additional free-radical fighters, including brightening licorice root, hydrating niacinamide, and reparative plankton extract. The lightweight, creamy formula applies easily and is packaged in an airless pump to keep the formula stable. If you’re consistent with your application, you’ll see your skin get brighter, smoother, and more even in about a month’s time—pretty impressive, if you ask us! We adore this formula and don’t really have any complaints about it, you’ll want to be sure to really massage the serum in to ensure it’s fully absorbed, especially around your hairline. The product has a yellow tinge that can be noticeable if it’s sitting on the skin’s surface. Formula: Creamy serum｜Concentration: Not listed｜Key Ingredients: Vitamin C, niacinamide, licorice extract｜Fragrance-Free: Yes｜Usage: Twice daily｜Size: 1 oz Best for Dark Spots Comfort Zone Skin Regimen 15.0 Vitamin C Booster Comfort Zone View On Comfortzoneskin.com What We Love: This serum uses a powerful dose of vitamin C in its purest form to give skin a glow.What We Don’t Love: Because of how active the formula is, you’ll have to use it up within a month before it destabilizes. Vitamin C is a notoriously unstable ingredient—even small amounts of exposure to light, air, and fluctuating temperatures will cause it to degrade, rendering it weaker or even completely ineffective. When you’re treating especially stubborn skin concerns, like dark spots, that just won’t do, which is why this formula from Comfort Zone is such a find. It comes in two parts: You receive a bottle of serum fortified with plant extracts and a concentrated dose of ascorbic acid (vitamin C) in powder form, which you mix into the serum right before you use it for the first time. Though it sounds crazy, our skin appeared immediately brighter after our initial application and just kept looking better and better from there. Because the product is so pure, you have to use it in its entirety within a month, lest it becomes ineffective. If you’re not a habitual skincare user, this product may not be for you. If you are reliable with your regimen, consider storing this one in your fridge to keep the serum extra fresh. Formula: Watery serum｜Concentration: 15%｜Key Ingredients: Vitamin C, spinach leaf extract, wild indigo extract｜Fragrance-Free: Yes｜Usage: Twice daily｜Size: 0.71 oz Best Anti-Aging RoC Daily Serum Ulta View On Amazon $25 View On Ulta $25 View On Walmart $27 What We Love: It’s clinically proven to tighten skin and improve elasticity in under four weeks.What We Don’t Love: This dropper can be a bit finicky, so it takes a few tries to get the right amount of serum out. This lightweight serum is beloved by dermatologists for its gentle formula and supreme moisturization benefits, making it a great first product for beginners. During our six-week trial, we found that our skin felt smooth, plump, and healthy, while the formula absorbed quickly with no oily or sticky residue. The glass bottle looks and feels luxe, but note that the dropper can be a little fussy; it will likely take you a few attempts to get it to suck up the optimal amount of serum. Once you get the hang of it, though, using this vitamin C is a breeze. Formula: Gel serum｜Concentration: 10%｜Key Ingredients: Vitamin C, peptides, glycerin｜Fragrance-Free: Yes｜Usage: Twice daily｜Size: 1 oz InStyle / Katherine Polcari InStyle / Katherine Polcari InStyle / Katherine Polcari Best Fast-Acting HoliFrog Sunnyside C Glow Serum Revolve View On Dermstore $48 View On Revolve View On Jcpenney.com $34 What We Love: This formula is fortified with a powerhouse blend of skin brighteners.What We Don’t Love: It leaves a slightly tacky finish to the skin. When you want to combat dull, discolored skin ASAP, you’ll want a product that’s packed with hardworking brightening ingredients, like this one from HoliFrog. In addition to containing 15 percent vitamin C, it features three percent tranexamic acid and two percent niacinamide—all ingredients that can fade hyperpigmentation, including stubborn melasma. In just a week of testing it, we noticed an improvement to our complexion. This is a fantastic product, but if you have sensory issues with some serums, be aware that this product can leave something of a sticky feel to the skin. While that can be a bit inconvenient when applying makeup, it doesn’t bother us when using it during our nighttime routine. Formula: Creamy serum | Concentration: 15%｜Key Ingredients: Vitamin C, niacinamide, tranexamic acid｜Fragrance-Free: Yes｜Usage: Twice daily｜Size: 1.01 oz Best for Hyperpigmentation BeautyStat Universal C Skin Refiner Vitamin C Serum + SPF 50 Mineral Sunscreen Ulta View On Nordstrom $26 View On Ulta View On Beautystat.com What We Love: This genius formula treats and prevents dark spots at the same time.What We Don’t Love: If you’re using the correct amount of sunscreen, you’ll burn through this bottle quickly. While vitamin C is one of the best hyperpigmentation-fading ingredients out there, the best way to combat discoloration is to prevent it entirely—which is what makes this formula so fantastic. It combines the powerhouse antioxidant with fellow free radical-fighter green tea and a mineral SPF 50 to simultaneously treat and prevent sun damage in one fell swoop. It has a silky texture with a subtle tint that helps it blend into richer skin tones (though keep in mind that it may still be a little ghostly on very deep complexions). Our only gripe with this formula is the size of the bottle. Though it’s on par with other vitamin C serums, it’s kind of small for a sunscreen. Considering that you should use about a half of a teaspoon’s worth of SPF on your face and neck—and there are six teaspoons in a fluid ounce—you can expect to use up this product very quickly. However, that’s not necessarily a bad thing: You’ll know that the vitamin C will be at its most potent. Formula: Fluid serum｜Concentration: 20%｜Key Ingredients: Vitamin C, green tea extract, mineral sunscreen｜Fragrance-Free: Yes｜Usage: In the morning｜Size: 1 oz Best for Daytime Use Drunk Elephant C-Firma Fresh Vitamin C Day Serum Amazon View On Ulta $79 View On Sephora $79 What We Love: This serum offers both instant and long-term benefits.What We Don’t Love: It smells kind of funky upon application. The “fresh” in Drunk Elephant C-Firma Fresh Vitamin C Day Serum refers to the active itself: It comes in powder form and is packaged separately from the serum, then mixed in the fluid formula once you’re ready to use it. This extra step means that the 15 percent vitamin C is especially potent, so you’ll see significant results. We saw dramatically more radiant skin after a few weeks of using this product, to the point that we couldn’t stop checking ourselves out in the mirror. We even got a few compliments from friends and family. The product absorbs nicely and feels very light on the skin, but remember that vitamin C can often have an unpleasant aroma. This serum does—it’s reminiscent of bacon—but the scent dissipates just a few seconds after you slather it on. Formula: Fluid serum | Concentration: 15%｜Key Ingredients: Vitamin C, ferulic acid, licorice root extract｜Fragrance-Free: Yes｜Usage: In the morning｜Size: 0.94 oz InStyle / Julia Sayers Gokhale InStyle / Julia Sayers Gokhale InStyle / Julia Sayers Gokhale InStyle / Julia Sayers Gokhale Best for Acne-Prone Skin TruSkin Vitamin C Facial Serum Amazon View On Amazon $22 View On Walgreens $25 View On Riteaid.com $24 What We Love: This serum is hydrating, glow-inducing, and friendly to acne-prone skin.What We Don’t Love: Though the formula features jojoba oil, it can be too drying on some complexions. Experimenting with facial serums can be tricky for the acne-prone—adding in too many different oils can cause blockage and breakouts. But we were quite pleased with this formula as it uses jojoba oil, which functions similarly to our skin’s sebum, to nourish skin, while infusing it with skin-balancing and -brightening vitamin C as well as hydrating hyaluronic acid. At no point did it cause breakouts or clog our pores, and we were impressed by how bright it made our skin look, even after we stepped off a 13-hour flight. With regular use, it continued to improve our complexion, fading dark spots left behind by old breakouts. This formula is pretty lightweight, which makes it ideal for those with acne-prone skin—if you have this skin type, you may find that this formula is nourishing enough to skip your moisturizer step. However, if your skin is on the dry side, be prepared to really layer on your richest creams after using this serum. Solely using this serum will not be enough to hydrate your skin if it’s dry or dehydrated, which may be due to the inclusion of witch hazel in the formula. Formula: Fluid serum｜Concentration: Not listed｜Key Ingredients: Vitamin C, hyaluronic acid, jojoba oil｜Fragrance-Free: Yes｜Usage: In the morning｜Size: 1 oz InStyle / Emily Cieslak Best Hydrating Biossance Squalane + Vitamin C Rose Oil Sephora View On Sephora $74 View On Biossance.com View On Kohls.com $40 What We Love: This oil creates such a serious glow, you won’t even need foundation.What We Don’t Love: If you have oily skin, this could make you look a little greasy. Those who are looking for a serious dose of nourishment in addition to brighter skin will adore this formula from Biossance, which has earned us countless compliments on our glowy complexion. The squalane in this formula works to lock in moisture and provide long-lasting hydration, while the vitamin C boosts luminosity and the rose oil adds extra hydration (and a lovely aroma). The deep moisturizing effects of this product’s squalane made our skin look so healthy and fresh—like we’ve gotten an amazing night’s sleep—that we ended up skipping foundation quite frequently to show off our radiant face. If you have oily skin, this product likely won’t be for you—it’s not so much a serum as it is a true oil, so it may leave your skin looking a little slick. If you have a dry or normal skin type, you will greatly appreciate the major glow that comes courtesy of this treatment. Formula: Face oil｜Concentration: Not listed｜Key Ingredients: Vitamin C, squalane, rose oil｜Fragrance-Free: Free of artificial fragrances｜Usage: Twice daily｜Size: 1.01 oz InStyle / Madison Yauger Best for Sensitive Skin Paula's Choice 25% Vitamin C + Glutathione Clinical Serum Sephora View On Amazon $62 View On Sephora $62 View On Kohls.com $62 What We Love: Though this formula features a seriously potent dose of vitamin C, it’s made with a blend of gentler forms of the ingredient, so it won’t irritate skin.What We Don’t Love: You may not like the scent. If other vitamin C serums have made you break out or irritated your skin, give this one from Paula’s Choice a go. The silky, creamy formula feels like a very lightweight moisturizer, yet absorbs quickly to deliver a dose of ultra-concentrated yet gentle vitamin C. The forms used in this serum are highly stable and less sensitizing—and the addition of antioxidants leave skin feeling extra soothed and bright. With regular use, we noticed our skin looking supple, smooth, and radiant (and nourished to boot). While we don’t have an issue with the natural scent of the product—it smells a little citrusy, in our opinion—some might find it to smell artificial or plastic-like. This is a common gripe when it comes to vitamin C serums, however. Your mileage may vary. Formula: Creamy serum｜Concentration: 25%｜Key Ingredients: Vitamin C, glutathione, ergothioneine｜Fragrance-Free: Yes｜Usage: Twice daily｜Size: 1 oz Best for Oily Skin La Roche-Posay Pure Vitamin C Face Serum Amazon View On Amazon $45 View On Ulta $36 View On Laroche-posay.us What We Love: This lightweight serum sinks into skin to combat oily skin, enlarged pores, and blemishes with salicylic acid.What We Don’t Love: This formula is extremely potent and those with easily sensitized skin should steer clear. Because of vitamin C’s collagen-boosting properties, the ingredient is a great pick for enlarged pores—but to really balance skin and make pores look even smaller, you’ll want some salicylic acid in the mix. This La Roche Posay formula combines the two to clarify, illuminate, and even out skin, as well as the brand’s mineral-rich signature thermal spring water to help soothe and amplify the product’s antioxidant properties. We also appreciate how accessible it is. It’s worth noting that vitamin C and salicylic acid can cause sensitivity when applied individually, so the combo of the two could cause irritation if you have especially reactive skin. However, if you have resilient, oily skin, especially if it’s prone to blemishes, you’re going to love this one. Formula: Gel-like serum | Concentration: 10%｜Key Ingredients: Vitamin C, salicylic acid, thermal spring water｜Fragrance-Free: No｜Usage: In the morning｜Size: 1 oz Best K-Beauty Innisfree Green Tea Enzyme Vitamin C Brightening Serum Amazon View On Amazon $26 View On Sephora $32 What We Love: This lightweight formula absorbs easily and leaves skin instantly more radiant.What We Don’t Love: It may irritate very sensitive skin. This formula from K-Beauty brand Innisfree includes every ingredient you’d want in a serum designed to deliver glowing skin. The brightening properties of vitamin C and niacinamide are enhanced by fellow antioxidants vitamin E and ferulic acid as well as a resurfacing enzyme derived from green tea, which instantly helps remove dead skin cells to reveal fresh, luminous skin. Though this combo of potent ingredients might sound drying, but with glycerin, hyaluronic acid, and squalane flooding the skin with moisture, this product is a heroic, do-it-all serum. Though this product is largely well tolerated by most skin types, the light exfoliation provided by the green tea enzyme paired with potent vitamin C may prove to be too sensitizing to some. We recommend patch testing to determine if this formula is a good fit for you. Formula: Gel serum | Concentration: Not listed｜Key Ingredients: Vitamin C, ferulic acid, green tea enzyme｜Fragrance-Free: No｜Usage: Twice daily｜Size: 1 oz Best Multitasking InnBeauty Project Vitamin C + Green Superfoods Jelly Serum Sephora View On Sephora $38 View On Kohls.com $32 View On Innbeautyproject.com What We Love: This serum is a real powerhouse — it helps clear pores, fade dark spots, and much more.What We Don’t Love: The product takes at least 30 seconds to absorb, so be patient when applying. This InnBeauty formula is a cross between a serum and an oil—it’s lightweight, but has a jelly-like consistency that takes some time to fully absorb. For a moment of patience, you will be rewarded with massive glow points. It’s fortified with a blend of vitamin C, pomegranate stem cells, and super-greens (including kale and spinach) to defend skin from free radicals, promote collagen production, smooth fine lines, and fade dark spots. It left our skin looking seriously luminous, firm, and more even in tone—we were especially impressed by the fact that it helped fade hyperpigmentation that we’d been trying to brighten up for years. So long as you commit to waiting for the formula to sink in, it should be smooth sailing—otherwise, you may experience some pilling, especially when applying it under makeup. Formula: Oil-jelly serum | Concentration: 1%｜Key Ingredients: Vitamin C (THD), aloe, proprietary supergreens complex, pomegranate stem cells｜Fragrance-Free: No added fragrance｜Usage: Twice daily｜Size: 1 oz Best for Dry Skin Mara Chlorella + Reishi Sea Vitamin C Serum Sephora View On Sephora $96 View On Themarabeauty.com What We Love: Skin glows instantly after the application of this serum, which is housed in stunning glass packaging.What We Don’t Love: This formula may cause breakouts in very acne-prone skin. Our skin tends to be on the drier side, and it drank up this hybrid face oil-serum in a snap. The ultra-clean formula is packed with THD as well as adaptogens and vitamin C-rich plant extracts that left our skin soft and luminous immediately; over time, it made our skin look fresh, even, and firm. We’ll also note that we’re obsessed with the ombré glass packaging, which looks gorgeous sitting out on our vanity. While we adored the nourishing formula (which uses plant oils and squalane to support the skin barrier), those with skin that breaks out very easily should consider patch testing before committing to a full-face application of this serum as it’s richer than most. Formula: Face oil｜Concentration: 15%｜Key Ingredients: Vitamin C, squalane, reishi mushroom｜Fragrance-Free: Yes｜Usage: Twice daily｜Size: 1 oz Best for Acne Scars Summer Fridays CC Me Vitamin C + Niacinamide Serum Amazon View On Sephora $68 What We Love: Though the exact concentration isn’t listed, this product features a heavy dose of actives.What We Don’t Love: The texture is sticky at first. If you’re looking for a high dose of an ingredient in a formula but the concentration isn’t listed, check out the label—the higher up on the ingredient list it is, the more of it is in the bottle. And in this product from Summer Fridays you’ll find niacinamide and two forms of vitamin C at the top of the list right after water, which gives the product its milky, fluid feel. These actives are known skin brighteners, with niacinamide in particular being great for post-acne marks due to its additional anti-inflammatory properties. With regular use, this serum does an excellent job in evening out overall skin tone and fading discoloration. If you’re particular about the texture of your serums, be aware that this one can be a little sticky before it fully absorbs. However, that’s par for the course with vitamin C, which is just inherently tacky-feeling. We’re confident you’ll appreciate the results of this product once you get used to the sensation of it as it sinks in. Formula: Milky serum｜Concentration: Not listed｜Key Ingredients: Vitamin C, niacinamide, squalane｜Fragrance-Free: Yes｜Usage: In the morning｜Size: 1 oz Best for Mature Skin Alpyn Beauty Vitamin C & Bearberry Instant Glow Serum Sephora View On Sephora $59 What We Love: The formula is pearlescent, so it’ll make skin look instantly radiant upon application.What We Don’t Love: A little goes a long way—apply too much and it may pill up on your skin. This product features mica, an ingredient with a luminizing effect that blurs the look of uneven texture and tone on contact—but the formula features a whole lot more than cosmetic benefits. There are hardworking plant extracts in here—including brightening bearberry and retinol alternative bakuchiol to firm and smooth—as well as resurfacing azelaic, lactic, and glycolic acids to leave skin looking younger and brighter over time. (Be sure to pair this one with SPF, as these chemical exfoliants can leave skin sensitive to sun exposure.) The formula makes your skin so glowy that we found ourselves skipping foundation, but if you do opt to wear it on top of this serum, choose wisely. This product features a creamier texture and a squalane-rich base that can cause it to pill up on the skin, even if you’re not wearing makeup, so you’ll want to be extra cautious when layering it with foundation to make sure everything lays smoothly. Formula: Creamy serum｜Concentration: Not listed｜Key Ingredients: Vitamin C, bearberry, bakuchiol｜Fragrance-Free: Yes｜Usage: Twice daily｜Size: 1.7 oz What to Keep in Mind Type of Vitamin C: Out of the many forms of vitamin C, L-ascorbic acid is the purest and most potent, says Dr. Kim, and tetrahexyldecyl ascorbate (THD) is a close second. Being water soluble, l-ascorbic acid can't reach the deeper layers of the dermis without a supporting cast of hydrators and antioxidants, like vitamin E, ferulic acid, vitamin B, and hyaluronic acid. "Although L-ascorbic acid can be irritating, it's the best option for oily and acne-prone skin," says Dr. Kim.THD is a precursor of vitamin C and known to be more stable and oil soluble so it can penetrate skin easily and without triggering irritation, but it’s newer on the scene and thus there’s less clinical evidence of its efficacy. That said, there are studies that show that the ingredient is less irritating than L-ascorbic acid, says Dr. Kim, who recommends it to his patients with sensitive and dry skin. Like the OG vitamin C, it can protect skin from free radicals, inhibit the formation of hyperpigmentation, and promote new collagen production. Concentration: To reap all the power of vitamin C, Dr. Kim says to look for a product with an active concentration of 10 to 15 percent or higher. “Most studies demonstrate clinical benefits like brightening, decrease in sunburn cells, and more when vitamin C is at that range,” he says, although he adds that it's wise for sensitive skin types to start with a lower dose and increase as your skin tolerates it. Additional Ingredients: Vitamin C serums formulated with soothing and hydrating ingredients can help reduce the risk of potential irritation, especially if your skin is sensitive or the skin barrier is compromised. “Studies show vitamin E and ferulic acid can improve L-ascorbic acid’s stability,” says Dr. Kim. "There’s also evidence that these ingredients make them all work more effectively to fight sun damage." To boost moisture levels, Dr. Kim recommends products packed with hyaluronic acid and glycerin, along with a generous dose of calming ingredients, like allantoin, centella asiatica (also known as cica), colloidal oat, and niacinamide. For even more defense against discoloration, serums made with licorice can help strengthen vitamin C’s abilities to reduce hyperpigmentation. Packaging: How a vitamin C product is stored—both by the manufacturer and you at home—can make all the difference in its efficacy. “Vitamin C is relatively unstable and can oxidize with light or exposure to oxygen,” warns Dr. Kim. “It's ideal for it to be housed in an opaque airless tube or an opaque glass bottle with a dropper." For extra insurance, keep your vitamin C serum in a cool, dark place (a.k.a. not your bathroom or at least not next to your shower). Your Questions, Answered When should I use vitamin C serum? “Vitamin C is best applied to dry, clean skin after you wash your face and before you apply your moisturizer,” says board-certified dermatologist, Dr. Purvisha Patel. “It has been proven to be an especially useful additive to your morning regimen before sunscreen, as it prevents damage caused by UV radiation.” Is it ok to use vitamin C serum everyday? Generally, yes. “Vitamin C serums are safe for daily use for most skin types, but if you notice increased dryness or your skin starts to peel or flake, then the concentration in the vitamin C serum you're using may be too high for you," says Dr. Patel. What are the disadvantages of using vitamin C serum? “Although higher concentrations of vitamin C will yield better visible results, if you're using a serum that contains a concentration of 20 percent or more, it's normal to experience some sensitivity as your skin adjusts to the new product,” says Nicole Frontera, a nurse practitioner. Rest assured, this sensitivity will be short-lived, subsiding within two or three weeks. Can you use a vitamin C serum if you’re acne-prone? Yes, it's generally safe to use vitamin C actives on acne-prone skin, says Joshua Ross, a celebrity aesthetician at SkinLab, but there are several caveats. "If breakouts increase or sensitivity occurs, you should discontinue use," he says. Dr. Patel says anyone with acneic skin should avoid formulations made with strong exfoliating ingredients, like retinol or AHAs, in addition to vitamin C, as it is likely to overwhelm skin and trigger a negative reaction. Instead, choose a vitamin C serum with only one of these ingredients, ideally, alongside hydrating or soothing supporting ingredients. Who should not use vitamin C serum? "Some people, especially those with sensitive skin, can't tolerate strong vitamin C serums, so I always recommend starting with just a small amount of product first to see how your skin responds,” says Ross. "From there, you can increase the amount and frequency as your skin acclimates to the active." If you're prone to eczema or rosacea flare-ups, you should consult your dermatologist before integrating a vitamin C product into your regimen. Why Shop With Us Emily Orofino is a beauty writer, editor, and consultant with more than a decade of experience. For this story, she reviewed testing data from the InStyle editorial team, and interviewed four skincare experts for their insights, including celebrity aesthetician Joshua Ross, cosmetic nurse practitioner Nicole Frontera, and board-certified dermatologists Dr. David Kim and Dr. Purvisha Patel. Sources InStyle uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Telang PS. Vitamin C in dermatology. Indian Dermatol Online J. 2013;4(2):143-146.