Visitors at Jordan Lake say SPF is one of the most important things they look for when it comes to choosing a sunscreen.
Dr. Sue Ellen Cox, MD, FAAD is the owner and medical director of Aesthetic Solutions in Chapel Hill. She says having the right level of SPF is important, but there is another number on the bottle you should also check, the expiration date.
The Food and Drug Administration says sunscreen typically expires three years after it is manufactured. But the products can expire sooner if they are left out in the sun or in a hot car because that heat causes the chemicals in them to break down.
"Sunscreens will lose there efficacy. When you think about food, would you eat expired food? Probably not. How about expired medications? They're not going to be as strong or as effective. So you can think about sunscreen in that same way," said Dr. Cox.
When it comes to storing sunscreen, keep it out of direct sunlight and keep it in a cooler if possible.
"You don't want to keep it in a hot car, you want to keep it in a room temperature, ambient temperature you also don't want to use sunscreen that's been opened and multiple people have handled it, there could be bacteria in the sunscreen. If the sunscreen smells bad you don't want to use it if when it comes out of the tube if it's watery, you don't want to use it," Dr. Cox said.
If you are ever unsure how long you've had your sunscreen, the best bet is to toss it out and buy a new bottle.
Some sunscreens include a manufactured date instead of an expiration date so it's important to know which date is listed. If a product doesn't have a date on it, write it on the bottle yourself after you purchase it.