According to a new study from Consumer Reports, nearly half of sunscreens have a lower sun protection factor (SPF) than they claim on their bottles.

So, should you start buying sunscreen with a higher SPF to protect your skin from sun damage and lower your skin cancer risk?

Not necessarily, says Saira George, M.D., a dermatologist at MD Anderson in Sugar Land. But it’s a good reminder to use more sunscreen more often.