Sunscreen 101s, from SPF to how much to apply and how often, to how long you can keep it

Does a vegan diet protect against the sun? How many times can you reapply sun cream? A skin expert provides the facts about sun protection

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Experts recommend applying sunscreen 20 to 30 minutes before sun exposure, and reapplying at least every two hours and especially after swimming and drying off.
Photo: Shutterstock

Published: 11:15am, 13 Jul 2024

With the arrival of summer, hot days lure us to enjoy the outdoors. As always, myths about sun cream are making the rounds.

Does a higher sun protection factor (SPF) offer better protection? Can a vegan diet safeguard your skin? Does reapplying sun cream extend its effectiveness? This fact check reveals the truth.

Germany’s Office for Radiation Protection recommends applying sun cream 20 to 30 minutes before sun exposure. To maintain its protective effect, regular reapplication is crucial: “At least every two hours and especially after swimming and drying off.”

However, dermatologist Christoph Liebich from Munich clarifies that there’s still a limit to how much sun you can take, no matter how much you reapply.

If you use a sunscreen with SPF 10 and have a natural protection time of 10 minutes, your total protection lasts 100 minutes. After that, reapplying SPF 10 or even SPF 50 sunscreen won’t help. Photo: Shutterstock

“For instance, if you use a sunscreen with SPF 10 and have a natural protection time of 10 minutes, your total protection lasts 100 minutes. After that, reapplying SPF 10 or even SPF 50 won’t help,” Liebich explains.