You may think of it as the standout vitamin in your morning glass of OJ, but vitamin C also delivers a whole host of benefits when used topically—and chances are you’ve seen it popping up in your skin-care products more and more, according to Shape.

So what’s all the hype about? Well, skin docs love it for its multitude of anti-aging qualities, making it a smart solution for all kinds of complexion concerns. Here, the expert lowdown on this VIP vitamin.