Dr. Dean

Does Sunscreen Have An Expiration Date?

Posting Date: 06/14/1999

Virginia: Does sunscreen expire after a few years? I have a bottle of sunscreen with no expiration date.

Dr. Dean: I'd try the sunscreen and find out. Often, expiration dates are just guidelines, although some medications can be harmful if they're used after the intended date.

The zinc oxide in sunscreen will never expire. Zinc oxide is so stable you can make paint out of it. I'm not sure about sunscreen's other ingredients, but I assume it's a pretty durable product. Storing it in a cool, dark place prolongs its potency.

People who use sunscreen are at a higher risk for cancer, according to several studies. Sun worshippers are lured into staying out in the sun, because sunscreen blocks the B rays that cause burning. Meanwhile, the tanners are soaking up lots and lots of harmful A rays that don't cause sunburn, but can damage the skin. Even with sunscreen, your exposure to the sun should be moderate.

Next week I plan to do a story on the new generation of sunscreens to hit the market. They block UVA, and they have to be used when they're very fresh.

So try the stuff you have, if you're going to be moderate about it. If you plan to bake eight hours in the sun, buy some fresh sunscreen.