Dr. Alan Copperman speaks to Well and Good about how chemicals in sunscreen affect your fertility and endocrine system.

We’ve all been told time and time again to wear sunscreen—even when it’s not glaringly sunny. So, of course, we dutifully dab on a daily tinted moisturizer with SPF or slather on tons of sunblock at the beach feeling pretty virtuous.

But lately the skin protectant has been provoking a raised eyebrow (or two). About half of SPFs don’t live up to their claims, those that say “water-resistant” are pretty much lying, and now a very serious concern has been discovered by researchers at the University of Copenhagen: commonly used sunscreen filters could be lowering men’s fertility.