The Best Inventions of 2021
November 10, 2021 6:08 AM EST

Vitamin C skin-care products, which are proven to help fade dark spots and even out skin tone, are more popular than ever. But after surveying customers, Supergoop! founder Holly Thaggard found few users were aware that the active ingredients in vitamin C treatments are rendered ineffective by the sun and, as a result, need to be paired with an SPF. “We wanted to create a formula that could solve that problem in one fell swoop,” she says. Combining the two is harder than it sounds: both SPF and vitamin C require specific pH environments in order to stabilize, Thaggard explains, which makes them difficult to formulate together. Making the final result scentless and transparent also proved tricky. The Daily Dose Vitamin C + SPF 40 Serum ($46) took more than three years and 15 iterations to perfect—but it’s since become the brand’s most successful direct-to-consumer product launch to date. —Taylor Bryant

Buy Now: Daily Dose Vitamin C + SPF 40 Serum

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