When it comes to vitamin C in skin care, timing matters. While you'll get benefits when you use your vitamin C serum in the morning or at night, you may be getting even more from this antioxidant powerhouse at one time of day.
A basic skin-care routine should involve cleansing, moisturizing and sunscreen, as TODAY.com explained previously. And when you're ready to add another step, vitamin C is an obvious choice.
But vitamin C is notoriously "finicky," Victoria Fu, cosmetic chemist and co-founder of Chemist Confessions, tells TODAY.com. Not only is it a challenge to keep stable in a skin care formula, the way you use vitamin C — including when you use it — and how you store it can impact its effectiveness.
To get the most out of your favorite vitamin C serum, follow this expert advice.
What does vitamin C do in skin care?
As a powerful antioxidant in the skin, vitamin C helps protect against sun damage, prevent the breakdown of collagen and manage pigmentation issues, Dr. Shari Lipner, associate professor of clinical dermatology at the Weill Cornell Medical Center, tells TODAY.com.
There's even evidence that, with consistent use, vitamin C can help treat melasma, a stubborn skin pigmentation condition, Lipner says.
Because you may not see the preventive effects of using vitamin C until years down the line, it can be hard for some people to "take that leap of faith," Gloria Lu, another cosmetic chemist and Chemist Confessions co-founder, tells TODAY.com.
But all these protective and skin-brightening benefits make vitamin C one of the best skin antioxidants for many people, Lu says.
Should you use vitamin C in the morning or at night?
You can safely use vitamin C products in the morning or the evening, the experts say. Whether you use it in the morning or at night "is actually not too big of a deal," Fu says.
Generally, experts recommend using it in the morning because its antioxidant sun protection pairs well with the benefits of using SPF, she says. But using it once a day — at whatever time you choose — will still provide some benefits.
"For someone who would want to put on the vitamin C at night, I think that's perfectly fine," Lipner agrees. "There's nothing (about using vitamin C at night) that would exacerbate any skin condition."
But, she adds, in the morning, you do get the added benefit of vitamin C giving you some sun protection. And there's some research to back this up, Fu says.
In one clinical trial, researchers applied a vitamin C product and a placebo cream on participants' skin once a day for four days. The researchers then applied UV radiation and measured the how well the vitamin C protected skin. They found that the accumulated four days of vitamin C product protected against skin swelling, as well as the formation of sunburn cells and skin cancer-related DNA mutations.
Interestingly, vitamin C doesn't seem to help after the fact, Fu says. In a small study, researchers looked at whether or not applying vitamin C between 30 minutes and two hours after UV exposure. They found that it didn’t have the same helpful, protective properties as applying vitamin C beforehand, Fu explains.
That means that, while you may get some of the other helpful benefits of using vitamin C, using it in the morning before you go outside will also help protect you from the skin-damaging effects of the sun exposure.
The other factor consider is what other products you're using in your routine. "There's just a lot of actives that end up getting paired in the evening," Fu says, including retinol and exfoliants. While you might not have any issues with any of those products on their own, the combination can be too much for some people — especially those with more sensitive skin.
On the other hand, "there's plenty of space in the daytime routine where (vitamin C) makes sense," Fu says. She recommends most people use it in the morning, before your moisturizer and SPF, "but, honestly, if (you're) applying it at night, that's totally fine as well," she says.
Can you use vitamin C more than once a day?
If you're tackling some hard-to-treat skin hyperpigmentation, you may be tempted to use vitamin C more than once. And, generally, there isn't anything wrong with that.
You can use vitamin C in both your morning and evening skin-care routines, provided it's not irritating your skin, Lipner says.
When it comes to treating pigmentation conditions, some clinical studies do have participants use vitamin C twice a day, Fu says. "But most of the data is actually using it once a day."
So, if you feel like doubling up, go for it. But keep in mind that high-quality vitamin C serums can be quite pricey, Fu says, and you only need to use it once a day to get major benefits.
"You can use it up to twice a day," Lu says. "And it slots right into your morning routine perfectly, since it has a lot of data on photo-damage prevention."