3 Things Your Sunscreen Label Isn't Telling You
SPF 100 isn't twice as strong as SPF 50. Not even close.
Sunscreen is one of the best things you can do for your skin. The label around it is where things get slippery.
1. SPF numbers hit a wall fast
SPF 30 blocks about 97% of UVB. SPF 50 blocks about 98%. SPF 100 blocks about 99%. The number doubles; the protection barely moves. High-SPF labels mostly sell confidence — and often make people apply less, thinking they're covered.
2. "Broad spectrum" is the phrase that matters
SPF only measures UVB, the burning rays. UVA — the deeper, aging rays — isn't in that number at all. If it doesn't say broad spectrum, a high SPF is only guarding half the door.
3. You're probably using a quarter of what's tested
Those SPF ratings assume a thick, even layer — roughly a shot glass for your whole body. Most people apply a fraction of that, which quietly turns an SPF 50 into something much lower.
The move
Look for broad spectrum, pick SPF 30–50, and use more than you think you need. Reapplying beats a bigger number every time.
Ask kiiwii
- What SPF should I actually use?
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- How often should I reapply?
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