Vitamin C was one of the most-searched-for beauty products of 2017. There’s just one problem: Vitamin C can lose its potency just by opening the bottle of serum or moisturizer that contains it.

Enter vitamin C powder, a powdered version of vitamin C that has all the above benefits without the instability. You just add the mix-as-you-go ingredient into your favorite serum or moisturizer, and presto!—the powder stays more powerful, lasts longer, and supercharges products you already have.

Here’s what you need to know before adding vitamin C powder to your beauty routine: