SPF Demystified: Why Bigger Numbers Aren't a Free Pass
Dermatologists explain that SPF mainly measures UVB protection; higher numbers don’t double protection (SPF 30 blocks ~97% UVB, SPF 50 ~98%, SPF 100 ~99%). Choose broad-spectrum, water-resistant formulas and reapply every two hours (or after swimming/sweating). Combine with shade, hats, sunglasses, and protective clothing for best sun protection.