Plenty of experts swear by the perks of protein powder. Not only can it help you build muscle and slim your waistline, but you can also use it to make the best post-workout snacks for refueling.
Fitness junkies have taken the advice to heart, too. Fifty percent of female recreational endurance athletes and 100 percent of female bodybuilders report using protein supplements, according to a 2013 survey published in The FASEB Journal. What’s more, a 2015 study found that one in five men regularly eat protein drinks or bars instead of meals.
But there’s one worrisome downside to protein powders, aside from eating too much. Shakes and smoothies that contain whey protein could cause more acne breakouts, just like these notorious foods that cause acne.
Dermatologist Dr. Mona Gohara and her colleagues have seen increases in acne breakouts in women who put whey protein in their drinks, Women’s Health reported, and research even supports Dr. Gohara’s theory. After following 30 participants who ate whey every day for two months, one study found that female participants were more likely to experience breakouts. Another small study of five male subjects suggests that cutting whey protein from their diet cleared their skin.
While no one really knows why this link exists, some researchers suggest that whey might increase the production of insulin, which can cause breakouts. Others say there might be a connection between acne and dairy, because whey is a part of milk.
Still, these studies are small, and not every expert is on board. “The hardcore evidence is skimpy,” Hilary Baldwin, M.D., acne expert and medical director of the Acne Treatment and Research Center told SELF. But if acne is a consistent problem for you, and you also drink shakes with whey protein, you might consider switching to pea or hempseed protein powder instead. You’ll get the same perks—without harming your skin.
That’s not the only way to pack in your protein. Here’s how to eat more protein without even trying.