What to Know About Collagen Supplements 

Other research shows promise for collagen supplementation as a way to improve bone health. One 2019 meta-analysis showed collagen supplements were associated with in a decrease in stiffness among people with osteoarthritis but didn’t make much of a difference in their pain or functioning. 

As for claims that the supplements support hair and nail health, the research is, well, brittle. One small study found people with weak nails noticed stronger, faster-growing nails after 24 weeks of taking collagen, but the study lacked a control group to which to compare. And research on collagen’s effect on hair health is largely in mice. 

Plus, “whenever you’re taking [a supplement], how do you know your body is going to use it for your skin or your hair?” Vasenina adds. “It’s not something we can tell it to do.” 

Vasenina’s research found that collagen supplements made “absolutely no difference” in muscle recovery. They did, however, seem to help prevent tendons from wearing down. Collagen products don’t “elevate muscle protein synthesis, which is important for muscle growth and tissue remodeling,” she says of her findings, “but [they] might do something with tendons.”

How to be a savvy collagen supplement shopper

To avoid some of the health (and financial) risks of trying a collagen supplement, follow these expert tips before adding a new product to your cart.

1. Prioritize protein-rich foods. Just like taking a multivitamin won’t cancel out a daily fast-food routine, stirring a collagen powder into your coffee (as Kobets does) isn’t worth it unless your diet is already solid.

“If people are already taking enough protein on a daily basis, then maybe taking 5 to 10 grams of collagen a day would be helpful,” Vasenina says. “But if their total protein consumption is low, then all these little things on the side are not going to make a difference.”

2. Beware of drug interactions and side effects. Most, if not all, supplements come with the risk of interacting with drugs and other supplements, so it’s always a good idea to check with your doctor before adding something to your regimen. For example, one supplement company notes that past research indicates high-protein diets, which extra collagen may mimic, might make some blood pressure medications less effective. 

Research suggests 2.5 to 15 grams of collagen daily is safe, but overdoing it can lead to gastrointestinal side effects like bloating and nausea, another company says.  

3. Look for the words “hydrolyzed” and “peptides.” Dr. Glenicia Nosworthy, an internal medicine physician who specializes in aesthetic medicine, says one of the biggest mistakes people make when shopping for collagen supplements is choosing something their bodies can’t absorb. “Many products on the market aren’t [absorbable], and they’re often loaded with synthetic fillers or added chemicals that do more harm than good,” says Nosworthy, founder of Glo By Glen in Brooklyn. 

That’s why she says it’s key that the supplement descriptions include the words “hydrolyzed” and “peptides.” The most effective formulas, she adds, are from marine sources and have about 5 grams per serving.  

4. Look for third-party testing. One 2020 paper from the Organic Consumers Association and the Clean Label Project found 64 percent of popular collagen supplement brands in the U.S. tested positive for measurable levels of arsenic, and more than one-third also had lead.   

But looking for a product that has been certified by an independent party like NSF — which tests supplements for harmful levels of contaminants and makes sure they contain what the labels say they do — can boost your confidence. “You want to stick with brands that at least claim that they test for heavy metals,” Kobets says. 

5. Take with vitamin C. For the body to use collagen most effectively, you need sufficient vitamin C, Kobets says. Nosworthy also suggests taking collagen products that include hyaluronic acid, glutamine and biotin. And if your aim is muscle support, there’s some evidence that taking collagen with whey protein can help. 

But ultimately, experts emphasize, you can’t pill-pop your way out of the practices known to support collagen production and youthful looks, like wearing sunscreen, not smoking, getting enough sleep and eating a whole-foods diet. Collagen, Kobets says, is just one more potential tool in the toolbox.