Vitamin C is a well-loved skin care ingredient known for it’s antioxidant protection, as well as its skin brightening and dark spot-fighting potential — not to mention it supports the body’s production of wrinkle-minimizing collagen and elastin. And during the peak of summer, it’s likely become a staple in your beauty routine to prevent sun damage and photo-aging.
Klarna, the all-in-one shopping app, reports that searches for vitamin C serums increased 255% between 2020 and 2021 alone. That’s why it has become a close second to daily SPF in terms of the most vital products to use consistently in your skin care routine (ask your dermatologist and they’ll confirm). But to truly make the most out of this potent ingredient, many skin care experts will advise you to look for formulas that pair vitamin C with other beneficial actives. It’s just about finding the right combination for your skin goals.
For starters, when choosing vitamin C skin care products, you have numerous options. “Vitamin C comes in two main forms — traditional [water-soluble] ascorbic acid, and [oil-soluble] vitamin C-esters,” says New York-based, board-certified dermatologist Dr. Joshua Zeicher. Oil-soluble vitamin C esters, like the ultra-brightening THD ascorbate, are considered more stable and better suited for sensitive skin, but there is a case to be made for water-soluble vitamin C forms, like ascorbic acid, too.
“Specifically, I recommend L-ascorbic acid,” says Birmingham-based, board-certified dermatologist Dr. Corey L. Hartman “This form of vitamin C has the most skin-related research of any form of vitamin C.” Traditional ascorbic acid is water-soluble and absorbs easily into the skin; the problem is, in this form it is highly unstable. As cosmetic chemist Ron Robinson, founder of BeautyStat, explains, “That means that it oxidizes, turns brown or orange and is rendered inactive.” Thus, strategic formulation by cosmetic chemists is the extra step needed to turn them into the everyday formulas you know and love.
This is why vitamin C serums often come paired with other antioxidants — to enhance the stability and shelf-life of this notoriously volatile antioxidant. “Antioxidants have the ability to donate electrons and stop the chain reaction of stolen electrons [that cause oxidation] without becoming highly reactive,” explains cosmetic chemist David Petrillo, founder of Perfect Image Skincare. In addition to preserving vitamin C’s efficacy, antioxidant and certain active ingredient pairings can also work synergistically with your skin type, addressing specific skin concerns from hyperpigmentation, to acne, to prejuvenation, with the potential to also offer enhanced photoprotection, hydration, and anti-inflammatory soothing depending on the blend you choose.
However, not all active ingredient pairings are naturally potent. In many cases, it requires extensive tweaking by cosmetic chemists in a lab to be able to work multiple popular active ingredients into a single, pH-optimized serum that is bio-available and tolerable for most skin types. This is why the best bet is to find a singular product as opposed to layering multiple serums. Petrillo notes, “When you start combining different products, you run the risk of altering the pH and effectiveness of the intended product [which has been made] in such a way to combine specific ingredients at specific concentrations.” By using multiple serums as opposed to one, you are therefore risking the dilution and inactivity of your preferred actives — and you may experience a negative reaction.
Keep reading to learn more about which active ingredients to seek in your vitamin C serums according to your specific needs.
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Vitamin C Pairings To Consider
For Straight-Up Vitamin C
For vitamin C purists that want L-ascorbic acid in its unadulterated, skin-loving glory, always remember look for airtight packages of L-ascorbic acid. For these formulas, it is important that they do not have detachable, dropper lids, which can let air and light in. Accordingly, their packaging should always be sealed from the light entirely — whether opaque or darkly tinted — to prevent UV-induced oxidation.
If You Need Extra Hydration: Hyaluronic Acid
If your skin is dehydrated and dull, a hyaluronic acid and vitamin C combo might be exactly what you needs. HA is a hydrophilic ingredient and comes in multiple molecular weights to impart hydration at different skin depths. The humectant attracts water molecules that also makes it “plumping,” giving your skin that juicy effect. “This may [also] be a helpful combination for sensitive skin because the hyaluronic acid may help reduce potential irritation from a vitamin C product,” Dr. Zeichner adds.
If You Need Brightening & Anti-Aging Benefits: Retinol
“Using both a vitamin C and a retinol in your routine helps to protect and repair the skin from sun damage, to prevent and fade dark spots from sun damage, and to stimulate collagen production,” says board-certified dermatologist Dr. Hadley King. But combining vitamin C and retinol at the same time of day is controversial, with many dermatologists reserving vitamin C for the daytime, and the vitamin A derivative for night. Others, however, consider the conversation to be changing.
“Previously, doctors believed that the acidic pH required for vitamin C absorption contributed to the degradation of retinol, but newer research suggests that combining retinol with vitamin C actually may help stabilize it,” says New York-based, board-certified plastic surgeon Dr. Lara Devgan. Dr. King corroborates this claim, referencing studies showing both that retinol retains its skin care effects paired with vitamin C, and that the presence of oil-soluble vitamin C promoted the photo-stability of retinol. This pairing, however, is not suitable for sensitive skin, which may be better inclined to receive the anti-aging benefits of the retinol-alternative, bakuchiol.
If You Need Extra UV & Free-Radical Protection: Antioxidants
The synergistic effects of multiple antioxidants can enhance the photoprotective abilities of vitamin C while stabilizing the active within skin care formulas. “[For instance,] vitamin C in combination with other antioxidants such as ferulic acid can help form a complex chemical structure that is stable dynamically,” Petrillo says of chemistry’s power couple. As Los Angeles-based, board-certified dermatologist Dr. Ava Shamban, founder of Ava MD, explains, “Antioxidants down-regulate the highly reactive free radical compounds, neutralizing them by donating an electron to stabilize their function protecting the skin.” They can even help prevent the breakdown of collagen and elastin in the skin, with ferulic acid, vitamin E, and CBD becoming popular vitamin C pairings.
For example, Dr. Hartman notes that ferulic acid is a great ingredient for tackling hyperpigmentation, unevenness in skin tone, and texture. Petrillo elaborates, stating that “Ferulic acid is found in the cell walls of plants where it primarily helps to protect and preserve it — and this is exactly the role it serves in skin care: it helps volatile ingredients like vitamin C last longer and work harder to fight free radicals.” Furthermore, pairing vitamin C with antioxidants like vitamin E promotes the stability of the ingredient, rendering the serum more effective on the skin. “Vitamin E, which is fat and oil-soluble, is quite stable and — in combination with ferulic acid especially — aids in boosting the properties of vitamin C, and stabilizes cell membranes, as well,” says Petrillo.
This can all be demonstrated by research. As Dr. King points out, the end result of this pairing can be seen in this study which found that ferulic acid stabilized a solution of vitamins C and E, doubling their free-radical fighting function for the skin. (Note that this is the very same combination found in the industry cult-favorite, SkinCeuticals CE Ferulic.) “Ferulic acid is a potent plant antioxidant that helps lower the pH level and improves the chemical stability of vitamin C by supporting intracellular antioxidant defense systems and protecting cells from the damaging effects of oxidation,” Petrillo says. To understand the function of vitamin E with vitamin C in layman’s terms, Dr. Zeichner says to “think of it like a rechargeable battery to help maintain stability and effectiveness.”
Lastly, cannabidiol (CBD) is frequently touted as an anti-redness, anti-inflammatory active, but it is also an antioxidant and thus stabilizing. Thus, CBD skin care that features vitamin C has the potential to promote free radical protection while also buffering sensitive skin types from the potential for irritation. Dr. Shamban considers the combination of vitamin C and CBD to be particularly effective post sun-exposure, stating, “CBD’s natural anti-inflammatory properties… cool and soothe the skin, while vitamin C helps repair free radical damage from UV exposure.”
If You Have Texture & Discoloration Issues: Exfoliating Acids
Bearing in mind that vitamin C requires an acidic pH to be absorbed by the skin, combining it with exfoliating acids like salicylic, lactic, and glycolic acids can be too aggressive for the skin, and also risks rendering the active ingredient inactive. “You don’t want to mix vitamin C with acids like salicylic acid. The salicylic acid will alter the pH of vitamin C, which will at best reduce its potency, but most likely will render the vitamin C useless.”
That being said, it can be done. “There are a number of products on the market that effectively combine the two, although results will vary by skin type and users should proceed with caution,” Petrillo says. “There are some that layer AHA with vitamin C, but they use a similar pH… Typically they increase the pH so that it is less aggressive on the skin.” He recommends opting for a brand whose formulations you trust, noting that SkinCeuticals has created a product — Silymarin CF — that customers seem to love. For a gentler option than the exfoliating acids, certain enzymes can also impart the intended effect.
If You Want A Firmer, Brighter Complexion: Peptides
Keeping in mind that experts occasionally disagree, Petrillo is opposed to combining vitamin C with peptides. “Generally speaking, it is not recommended to pair vitamin C with peptides, as they work best in their own right and can actually cancel out the function of the other when used together,” Petrillo warns. “This is because the copper in peptides oxidizes the ascorbic acid, which causes it to break down at a rapid rate — leaving it no time to perform properly.” That being said, Dr. Hartman has seen combinations of vitamin C and peptides that work well to brighten the skin’s tone and will often recommend these types of products to his patients.
If You’re Fighting Inflammation & Redness: Niacinamide
In some instances, the ingredient niacinamide is a worthwhile pairing with your vitamin C — but with a couple of warnings. “Pairing vitamin C with niacinamide can actually reduce its effectiveness, so I would recommend incorporating the two separately in your regimen — vitamin C is great to use in the morning, and niacinamide is great to use at night,” says Petrillo.
“Vitamin C also pairs well with niacinamide, and is a great combo for people looking to brighten the skin and to reduce inflammation and redness,” Dr. Hartman advises. The active ingredient — a form of vitamin B — is also known to help optimize skin barrier function, a protective mechanism that also helps to retain moisture in the skin while buffering it from irritation via environmental aggressors. “Safety testing is important here to make sure it won’t irritate sensitive skin types,” Robinson adds. “Use niacinamide at levels of 2-5%.”