I’ve tested dozens of vitamin C serums that promise the moon on a string, but this powder is the only one that delivers
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Vitamin C serums are a staple in any good morning skincare routine. The antioxidant pairs well with sunscreen, minimizing free-radical damage from UV exposure that can lead to skin issues down the line. It can also boost collagen and prevent the formation of dark spots by stopping an enzyme responsible for melanin production. That’s why so many of us reach for a vitamin C serum every day: it fades existing dark spots and prevents new ones from forming, leaving skin brighter and plumper.
But as I’ve previously reported , vitamin C is a notoriously fickle active ingredient. It’s unstable and spoils easily—no matter how you store it—which is why I’ve found myself frustrated with nearly all of the vitamin C serums I’ve tested. They leave my skin feeling perfectly lovely, but as for dark spots? Skin clarity? Overall tone and texture? They overpromised and underdelivered.
So when the founder of Exponent Beauty poured a dose of white powder into my palm and told me it was a vitamin C serum, I was immediately intrigued. The entire brand is built around the idea of ingredient stability—what good is vitamin C or retinol if it’s barely active by the time you open the bottle? The brand points to third-party data showing that active ingredients degrade by 40 percent in just six weeks.
Exponent’s solution is to keep the 10 percent pure L-ascorbic acid in a stabilized powdered form until you’re ready to use it. One pump of powder in your palm gets mixed with one pump of a hyaluronic acid serum. Swirl it around and sweep it over your skin. It’s easy, and even a little fun, recalling the childhood whimsy of potion-making.
Using the product is easy. Stamp the powder into your palm, then add a pump of the serum. Swirl it with your finger or rub your palms together, then apply it to slightly damp skin each morning.
I finished the Brightening Boost Vitamin C Power Serum set in about a month, but the results blew me away. My skin looked brighter, firmer, and healthier each morning. It never turned red or flushed after applying the serum, which is another huge bonus for me (vitamin C can be irritating). But the results go beyond just what my eyeballs saw in the mirror. Exponent, being run by science nerds after my jaded heart, put the serum through independent, instrument-measured clinical testing on 28 women. The results: 100 percent experienced a decrease in fine lines and wrinkles in one week; 72 percent experienced an increase in skin firmness in four weeks; and 66 percent experienced an increase in brightness and a decrease in discoloration in four weeks. Put simply, it just works.
I had a similar positive experience with Exponent’s retinol serum (no irritation, visible results), and I look forward to putting some of their other powdered products—a CoQ10 serum and green tea resveratrol serum—to the test.
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