Over 80% of sunscreen performed below their labelled efficacy (2020)

This is a topic where the details matter a lot. A sunscreen which is labeled SPF 50 but performs at SPF 45 is such a minimal difference that it would be impossible to notice in the real world. The variance of your application technique and applied thickness would actually matter more. There is also a lot of testing variability, so if a sunscreen rated to block 98% of certain rays only gets 97% in the test that would be acceptable in the real world, but it would get counted for this clickbait headline.

If a sunscreen comes with a high SPF rating and performs close enough in random testing (which is hard to replicate) then I wouldn’t have any concerns in the real world.

The body of the article has some more details about how the number of majorly deficient brands was much smaller, but that makes for less clickbaity headlines:

> The measured sunscreen efficacy of 4 models were below SPF15, of which 2 were sunscreen products with very high protection i.e. labelled with SPF50+

Knowing which 2 brands were labeled SPF 50 but performed below 15 would have been helpful, but the article is not helpful.

Have you tried living in Australia? I would like SPF 100 sunscreen pronto, please and thank you

SPF is a Sun Protection Factor, meaning it multiplies the time it takes for your skin to burn. For example, if very light skin normally burns in about 10 minutes, SPF 20 stretches that to ~200 minutes, which is already over 3 hours. Since dermatologists recommend reapplying every 2 hours regardless, going beyond SPF 30–50 (which blocks ~97–98% of UVB) doesn’t add much practical benefit. Even for very fair skin, correct application and reapplication are far more important than chasing SPF 100.