But picking one can be confusing. There are different types and different ingredients, and sunscreen labels are changing.
As if that weren't enough, you may have also heard warnings from some groups that some sunscreen ingredients are dangerous.
So what are you to make of all that? What about the risk of skin cancer? And what's in the bottle, anyway? Here are answers.
You may have heard that some sunscreens contain potentially dangerous ingredients, including the ones listed below -- all of which are approved by the FDA and supported by the American Academy of Dermatology (AAD).
Retinyl Palmitate: Derived from vitamin A, retinyl palmitate is added to some sunscreens to help reduce the signs of aging. It is not a UV filter, so it's not an essential sunscreen ingredient.
Some dermatologists feel that the research suggesting a connection between retinyl palmitate and skin cancer -- in lab tests on mice -- is worrisome.
"I would never use retinyl palmitate. When I give sunscreen suggestions, I always avoid the ones with retinyl palmitate," says Debra Jaliman, MD, FAAD, assistant clinical professor of dermatology at Mount Sinai School of Medicine and the author of Skin Rules: Trade Secrets from a Top New York Dermatologist.
Some sunscreen makers are removing retinyl palmitate from their products. Only about a third of sunscreens contain it.
Other experts say the ingredient is safe.
"Those animals [in lab tests] are prone to develop skin cancer in the first place and the amount [of retinyl palmitate] they were exposed to is significantly higher than what a human would be exposed to," says dermatologist Henry Lim, MD, former vice president of the AAD.
Vitamin A derivatives are used to treat skin cancer as well as acne. "It's been in use for at least 30 years, and there has not been any signal to show that it would result in the development of skin cancer. Bottom line: It's safe," Lim says.
Oxybenzone: Oxybenzone, a common UV filter, has been shown to interact with hormones when fed to animals in large amounts. Dermatologists say this is no reason to toss your sunscreen.
"If you covered your entire body with oxybenzone in the concentrations that are in sunscreens and used it every day, it would take over 30 years to get to the point of what these rats were fed in these studies," says dermatologist Darrell Rigel, MD, FAAD, who is a clinical professor of dermatology at New York University Langone Medical Center.
Nanoparticles: Zinc oxide and titanium dioxide offer broad-spectrum protection in what's called "mineral sunscreens." People who find chemical sunscreens irritating may prefer these mineral forms.