Sun protection without myths: what the SPF numbers mean

SPF shows how many times longer your skin tolerates the sun without reddening when the product is applied correctly, compared to unprotected skin. SPF 30 means about 30 times, SPF 50+ about 50 times and more.

The important part is that the difference between 30 and 50 is not double protection: SPF 30 blocks about 97 percent of UVB rays and SPF 50+ about 98 percent. For the face, however, I recommend 50+, because the skin there is the most exposed and we most often apply less product than needed.

This is the most common mistake: sunscreen should be applied generously. For the face and neck you need an amount equal to two finger lengths of product. With less, the real protection drops drastically below the number on the packaging.

Reapplication is every 2 hours when outdoors and always after swimming, sweating or towelling, even if the product says “water resistant”.

The two types of filters work differently, but both are safe and effective in quality products. Chemical filters absorb UV rays and allow lighter textures without a white cast, which makes them more pleasant for everyday use and under make-up.

Mineral filters reflect the rays and are often the preferred choice for very sensitive skin and for children. For the face in everyday city life I most often recommend a light non-comedogenic formula with SPF 50+ that is comfortable to wear, because the best sun protection is the one you will actually apply every day.

On a cloudy day UV rays still reach the skin, so protection is not skipped. Through glass, UVA rays also pass, so driving and working by a window are also sun exposure.

And finally: sunscreen does not prevent a healthy tan, it makes it safer and more even. And if your skin still gets burnt despite the precautions, see what to do in the first hours after sunburn. If you hesitate which factor suits your skin type, ask me in the chat: I answer personally and free of charge, for information purposes only, without diagnosis and without changes to your therapy.

This article was written by Donka Arabadzhova, Master of Pharmacy, and confirmed by the following sources: European Commission, Recommendation 2006/647/EC on the efficacy of sunscreen products. American Academy of Dermatology (AAD): recommendations on sunscreen selection, amount and reapplication. DermNet New Zealand: "Polymorphous light eruption", clinical review.