Dermelloa
Beginner·Sun protection·4 min read

Sunscreen: The One Non-Negotiable

What SPF and broad-spectrum actually mean, how much to apply, and why daily use is the most evidence-backed thing you can do for your skin.

If you do one thing for your skin, make it daily sun protection. UV exposure is the largest controllable driver of visible aging and a key risk factor for skin cancer. No serum comes close to its proven impact.

Reading the label

  • measures UVB protection — the rays that burn. SPF 30 blocks ~97%, SPF 50 ~98%.
  • Broad-spectrum means it also covers UVA — the rays that drive aging and penetrate deeper. You want both.
  • Water-resistant ratings (40 or 80 minutes) tell you how long protection holds during sweat or swimming.

Mineral vs chemical

Mineral filters (zinc oxide, titanium dioxide) sit on the surface and reflect UV; chemical filters absorb it within the film. Both are effective and safe. The best sunscreen is the one you will actually reapply.

Frequently asked

UVA passes through glass and clouds, so meaningful exposure happens near windows and on overcast days. Daily use is the simplest reliable habit.

Knowledge check

0 / 2 correct
  1. 1. What does "broad-spectrum" indicate?

  2. 2. Why do many people get less protection than the label says?

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