By Emily Wood, NEWS 9

OKLAHOMA CITY -- If you're heading outside this summer, even for a few minutes, you'll want to wear sunscreen. But do you know what's really in that lotion or cream you're putting on your kids?

Many of the popular sunscreens may not be blocking you and your family from the sun's cancer-causing rays.

Parents like Sarah Pierson slather on the sunscreen to keep the kids from getting burned. Pierson uses one with an SPF of 50 and so do many other parents.

Dermatologist Brandon Rhinehart says labels can be misleading.

"The SPF of 75 or 100 is greatly exaggerated and is not better than 30 and often costs quite a bit more," Rhinehart said.

Labels can be confusing. Dermatologists say you should focus less on the number on the front and more on the ingredients listed on the back.

The sun hits us with two types of rays, UVA and UVB. Most sunscreens protect the skin from UVB, but Rhinehart says it's just as important to block UVB. Ingredients such as titanium or zinc, avobenzone or mexoryl are the ones proven to do the blocking.

"We know UVA causes skin cancer," said Rhinehart. "We know UVA causes aging, wrinkles and dark spots."

Rhinehart says most sunscreens do not block the cancer-causing UVA rays, even if the front of the bottle says they do.

Dermatologists say no sunscreen product will block the sun out completely and say the best thing to do is wear a T-shirt and a hat to protect skin from the sun.