When it comes to sun protection, there's apparently a lot of fake news going around.

By Renee Cherry
Organic beauty cosmetics on marble, home spa flatlay background
Credit: anneleven/Getty Images

There are some things you just shouldn't DIY. Sunscreen, which plays an important role in lowering your skin cancer risk, is one of them.

What's more, Pinterest is full of homemade natural sunscreen recipes and misleading info on sun protection, according to a new study published in the journal Health Communication. (Related: The Best Face and Body Sunscreens for 2019)

Researchers searched "homemade sunscreen" and "natural sunscreen" on Pinterest and sampled every fifth pin for a total of 189 pins. What they found was a bit concerning: Of those, 95.2 percent included claims that homemade sunscreens are effective, and 68.3 percent included recipes for sunscreens that would provide inadequate UV protection, the researchers found. (Popular DIY beauty ingredients like coconut oil, shea butter, and essential oils were common.) About one-third of the pins claimed the recipe would provide a certain level of sun protection, ranging from SPF 2 to SPF 50. A lot of pinners had not only seen but bookmarked the info; the number of saves ranged from one to 21,000.

So here's why this is kind of alarming: The FDA has approved 17 active ingredients to be used in sunscreens, and for a formula to be effective and long-lasting, you need a combination of those ingredients, says Lara McKenzie, Ph.D., co-author of the study. Many of the Pinterest recipes in the study included zinc oxide, which is on the FDA's list, but that alone doesn't provide broad-spectrum protection, says McKenzie. "The recipes that we saw just had a couple of ingredients," she explains, "and you couldn't tell from the formulas if they would be effective, if they had been tested, and what level of SPF they would actually offer." (Related: Why Sunscreen May Not Be Enough to Protect Your Skin)

On the bright side, Pinterest isn't blind to the fake news its users occasionally share. It adopted a health misinformation policy in 2017 promising to remove pins with harmful health claims. "We don’t allow advice when it has immediate and detrimental effects on a pinner’s health or on public safety," the policy reads. "This includes promotion of false cures for terminal or chronic illnesses and anti-vaccination advice."

Recently, Pinterest cracked down on misleading anti-vax pins in light of the current measles outbreak. Time will tell if it gives SPF claims the same critical eye given the rising rate of melanoma in the U.S. (Related: How Often Should You Really Have a Skin Exam?)

If you prefer to opt for clean beauty products, you can go with a commercially available mineral (AKA physical) sunscreen. Their ingredients do go through a chemical processing during formulation, but they are overall more natural than chemical sunscreens. As for Pinterest DIYs, it's probably best to stick with hair masks and chunky blankets.

"I definitely think that there's a misconception that natural, organic, or homemade is safer or better," says McKenzie. "In this case, we're saying for sure that this is not better, this is not a safe option."