How to get the best results from antioxidant products.

Antioxidants can be confusing, especially in your skin care. Most are recommended for use in the morning (green tea, vitamin C), some at night (vitamin A, resveratrol), and still others are more effective when they’re applied together (vitamins C and E). Some forms are more active than others, but more active can mean less stable—and extra-irritating. But overall, they’re absolutely worth applying to your skin to fight free radicals that cause signs of age. So, we put together these golden rules to help you get the best results from these skin-savers. 

1. Your vitamins have a shelf life

Like watching a bunch of bananas turn brown, seeing your skincare products change hues is less than appetizing. And it turns out, it’s the same chemical process at work: Oxidation. However, a sudden change in a formula’s color doesn’t necessarily mean you’ve wasted your hard-earned dough. “When vitamin C becomes brown, it’s still active, although not as potent,” says Elizabeth Tanzi, MD, co-director of the Washington Institute of Dermatologic Laser Surgery. Renee Rouleau, a Dallas-based aesthetician to celebs like Demi Lovato and Anna Faris, agrees: “If a vitamin C serum turns darker in color, you'll get less visible and slower results,” she adds. “So brown spots and post-breakout red or dark marks may fade less quickly.”  

So, what’s the takeaway? Buy your serums in smaller doses: “One ounce is good and it will give you a 2 month supply,” says Rouleau. 

2. A higher concentration isn’t always better

It seems logical to assume that a steep percentage of actives will result in a more effective product, but, according to Rouleau, efficacy depends on the ingredient. “Formulas for vitamin C can range anywhere from less than 1% to 20%,” she says. “But the ones that contain between 10%-20% are acidic and might be really irritating.” Take L-ascorbic acid for example, which can be volatile (translation: more likely to oxidize and become ineffective) and inflammatory for sensitive skin types. Instead, Rouleau recommends looking for ingredients such as magnesium ascorbyl phosphate (MAP), ascorbyl palmitate, and sodium ascorbyl palmitate, which are all versions of vitamin C that are more stable and less harsh than their acidic counterparts. Her Vitamin C&E Treatment contains magnesium ascorbyl phosphate.

3. Sometimes you need a cocktail

Serums often contain multiple antioxidants, particularly vitamins C and E. That’s because antioxidants have been proven to be more effective when used together than on their own. A 2005 study published in The Journal of Investigative Dermatology (by SkinCeuticals co-founder Sheldon Pinnell, MD, chief emeritus of Duke University’s dermatology division) reported that a solution of 15% l-ascorbic acid (vitamin C) and 1% alpha-tocopherol (vitamin E) was four times more effective than either antioxidant on its own. This research prompted Pinnell to create SkinCeuticals C E Ferulic, which is now the gold standard in antioxidant serums. A later Pinnell study at Duke University Medical Center found that adding 0.5% ferulic acid, a plant-based antioxidant, further improved the serum’s ability to provide photo-protection and improved stability as well. 

When it comes to environmental oxidative stress (like smoke or sun exposure), we’re finding that a “combination of antioxidants can often be more effective than just one,” adds Michelle Copeland, MD, assistant professor of plastic surgery at Mount Sinai Hospital in New York and author of Change Your Look, Change Your Life. But there are still ongoing studies being done. “If you look at skin cells treated with one antioxidant versus another or together, you can get cumulative improvement [with the combination].”

Bottom line: in terms of antioxidant diversity, more is more. 


  1. The Journal of Investigative Dermatology
  2. Vitamins C and E Study