Sunscreen.

What the gurus are saying

The gurus who tested it praise Polypodium Leucotomos as having strong evidence for preventing sun damage, and one expert noted real-world protection kept their skin noticeably pale during heavy sun exposure. That means it's built on a solid active ingredient backed by research. The main thing to keep in mind is that like any sunscreen, it works best with consistent reapplication every two hours or more often, rather than relying on a single application.