Bottom line: Vitamin C serum helps reverse and prevent signs of aging, keeps skin firm and youthful, and protects from UV rays. Invest in a bottle. Now.
“Because vitamin C serum helps protect your skin from free radicals, most dermatologists have recommended applying it in the morning to prevent damage during the day,” says Joshua Zeichner, the director of cosmetic and clinical research at Mount Sinai Hospital in New York City. And chances are the back of your bottle does, too. “But given the newest data, which shows that UV damage continues for hours after you’ve left the sun, perhaps we should also be using antioxidants, like vitamin C, in the evening to fight post-sun sun damage,” he says.
And wearing antioxidants at night still helps you fight sun damage the next day. “Your body builds up a storage of antioxidants as you use them,” says Zeichner, “so using vitamin C serum at night will help guarantee your body has enough ready to go in the morning when you need them most.”
No matter when you layer on your vitamin C, make sure to never use it within a few hours of salicylic acid, glycolic acid, or retinol (yes, that even includes face washes and spot treatments) to avoid burning, stinging, and redness.
You might think of vitamin C as a good ol’ citrusy immunity booster, shelved in your medicine cabinet for when you need to kick a cold. But when applied topically, it’s a powerful addition to an anti-aging skin-care regimen. “Vitamin C is essential in collagen synthesis,” says Dendy Engelman, a dermatologist at Manhattan Dermatology & Cosmetic Surgery. How does the magic work? When applied to the skin directly, the antioxidant neutralizes free radicals (atoms or molecules with an unpaired electron) that age you. “When a free radical steals an electron from one of the proteins in a strand of collagen, it creates a tiny break in the strand,” Engelman explains. The more breaks you retain, the more damage you’ll see as skin begins to sag and wrinkle. Since vitamin C is an electron donor, Engelman says it helps reverse and prevent signs of aging. Use it to keep skin firm and youthful and protect yourself from UV rays.
I didn’t start using Vitamin C on my skin until about 6 months ago and it’s made all the difference in the world. As I’ve gotten older, I’ve noticed my skin is less radiant and just looks more ragged. How joyous. A friend mentioned that she had been using this Vitamin C serum for a few weeks and was loving the results so I decided to give it a try. I’ve had such amazing results with this serum that it will be one of those products that is forever in my medicine cabinet. I put on a dime sized amount before my morning moisturizer every day and as a result my skin is much brighter and more boosted.
Because Vitamin C serum helps protect your skin from free radicals, most dermatologists have recommended applying it in the morning to prevent damage during the day but since UV damage continues throughout the day, I use a serum at night, as well. My nighttime serum is more concentrated since my skin won’t see sunlight.
No matter when you wear Vitamin C serums, make sure to never use it within a few hours of salicylic acid, glycolic acid, or retinol to avoid burning, stinging, and redness.
I highly recommend visiting your local Bluemercury store or trying out some of the Vitamin C serums I’ve listed below to kick start your newest skin obsession.

H-Ole moly — love that you still use this stuff! It’s my favorite :)
It’s amazing! Thank you for the introduction!