Sunscreeen 101 - Your Guide to SPF

April 17, 2025

Christopher Schmidt, MD

Co-Founder & Dermatologist

chris@dermasport.com

With longer days, stronger sun, and more activity, you need an SPF that can keep up with you. But with so many terms on sunscreen labels, it’s easy to get confused. That’s why we’re breaking down the basics—so you can feel confident you're choosing the best with Dermasport.

Sunscreen Glossary

SPF = sun protection factor, a measure of how well sunscreen protects skin from sunburn

UVB rays = invisible, high-energy ultraviolet (UV) radiation that causes sunburns and skin cancer

UVA rays = longer-wavelength UV that penetrates deeper, causing wrinkles, dark spots, and aging

Pro tip: Remember this, UVA = Aging. UVB = Burning

Broad Spectrum = protects against both UVA & UVB rays (the gold standard)

Water resistant = keeps protecting even after swimming, sweating, and drying off—typically for 40–80 mins.

Mineral SPF = utilizes zinc oxide or titanium dioxide to physically block UV rays (great for sensitive skin).

Chemical SPF = absorbs UV rays and converts them into heat to protect skin.

Fun Fact: SPF is based on how much solar energy it takes to burn protected vs. unprotected skin—not how long you can stay in the sun.

What Athletes Are Saying
about Dermasport

"I've tried just about every sunscreen there is and Dermasport is the only one that stays on for the entirety of my workouts." - Sarah H.

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Designed by Dermatologists - Our dermatologist, Dr. Christopher Schmidt, has been swimming for over 50 years. His first-hand experience battling dry skin, sunburns, and goggle marks propelled him on a decade-long scientific journey to develop the best skincare technology for his fellow athletes.