Q: Does a sunscreen with a high SPF better than one with a lower SPF? How high should I go?
A: An SPF 30 still allows about 3 percent of UVB rays to hit your skin. An SPF of 50 allows about 2 percent of those rays through. That may seem like a small difference until you realize that the SPF 30 is allowing 50 percent more UV radiation onto your skin. 
At best, high-SPF sunscreens give you only slightly better protection than a sunscreen with SPF 50, according to the annual sunscreen report published by the Environmental Working Group (EWG). At worst, they could give you a and make you spend more time in the sun — upping your risk for burns and skin cancer.
Under ideal conditions (like in a laboratory), a sunscreen with higher SPF protection and broad-spectrum coverage offers more protection against sunburn, UVA damage and DNA damage than comparable products with lower SPF values.
, real life is not like a lab. In real life, products with very high SPFs often create a false sense of security. People who use them tend to stay out in the sun much longer. They may skip reapplying. And they may think they don’t need to seek shade, wear a hat or cover up with clothing. They end up getting a lot more UV damage.
It’s important not to rely on high-SPF sunscreens alone. No single method of sun defense can protect you perfectly. Sunscreen is just one vital part of a strategy that should also include seeking shade and covering up with clothing, including wide-brimmed hats and UV-blocking sunglasses.
In 2011, the FDA even went as far as to call sunscreens with SPF values greater than 50 ” .”
Experts also worry that high SPF products might make people spend more time in the sun because they think they’re getting extra protection.
This is another major downside of higher-SPF products. A product with SPF can protect you from sunburns, but it could still leave you vulnerable to doses of UVA radiation.
To ensure you’re getting equal protection from both types of radiation, check the ingredients list. The product should contain 3% avobenzone or at least 15% zinc oxide. Both ingredients block UVA. Besides , look for +++ in the product label.
Important facts must be mentioned twice: Don’t let sunscreen do all the heavy lifting. Shade, hats, sunglasses, and clothing should be part of your sun protection, too.