The Science and Hype of Collagen Supplements

After Sonya Kenkare had a baby, her hairstylist recommended collagen to prevent her hair from falling out. But the board-certified dermatologist was skeptical. “I haven't done it because there isn't a lot of evidence,” says Kenkare, of Rush University in Chicago. Marketing materials and celebrity testimonials insist that collagen is a one-stop solution for aging skin, hair, nails, bones, joints, and more. And plenty of consumers have bought in. People spent $2 billion on collagen supplements in 2025; a total that is projected to keep growing. For now, the hype may be a step ahead of the science. Still, some studies suggest potential benefits, with plenty of details yet to work out. Here’s what we do and still don’t know about collagen for skin health, inflammation, pain, and more. Collagen is the most abundant protein in mammals, making up 30 percent of the proteins in our bodies. It is a key structural element of skin, ligaments, muscles, tendons, bones, blood vessels, the intestinal lining, and other connective tissues, says Julia Zumpano, a registered dietitian at Cleveland Clinic’s Center for Human Nutrition. Shaped like a triple helix with three chains of amino acids twisted together tightly enough to make the protein strong and rigid, collagen has been categorized into 28 types, based on molecular structure and where it is found in the body. Ninety percent of the body’s collagen is Type I, which is found in skin, bones, tendons, and ligaments, according to the Cleveland Clinic. Types I through V are more common than the rest. In our bodies, collagen is primarily made by specialized cells called fibroblasts. To string together amino acids into collagen, these cells also need nutrients such as vitamin C and zinc, Zumpano says. Collagen’s main job is to provide support, strength, and structure. It gives elasticity to the skin and protects organs. It also helps blood clot and new skin cells grow. When the body can’t make sufficient collagen, these processes break down. In people with the genetic disorder Ehlers-Danlos syndrome, which impairs the body’s ability to produce collagen, symptoms can include soft and stretchy skin, excessive bruising, and unstable joints. Autoimmune conditions such as lupus and rheumatoid arthritis can also damage collagen. After age 40, we lose about 1 percent of the collagen in our bodies each year. By age 80, collagen loss can reach 75 percent. With less collagen to support tendons and ligaments, many people develop chronic pain that prevents them from staying active. Meanwhile, as collagen levels decline in the dermis, an inner skin layer, skin sags and becomes wrinkled. A variety of factors can accelerate that process. Studies show that over time, smoking, alcohol, UV light, and high sugar consumption all lower collagen production and make the protein weaker, leading to more wrinkled skin. The market is full of collagen products, but they are not regulated like drugs. As a dietary supplement, collagen does not require premarket review and approval from the U.S. Food and Drug Administration. The FDA's website states: "The FDA does NOT have the authority to approve dietary supplements for safety and effectiveness, or to approve their labeling, before the supplements are sold to the public." Products may advertise collagen derived from beef (bovine), fish (marine), chicken, or other sources. They may specify the form, such as Type I or III. Some labels use the words “collagen peptides” or “hydrolyzed collagen.” Both are short chains of amino acids that are easier to absorb than whole collagen proteins. Supplements may be in the form of pills, powders, gummies, or drinks. It is safe to take collagen daily, Zumpano says. Collagen is a primary ingredient in many of the filler injections used in cosmetic procedures, which can plump up the skin temporarily before getting broken down by the body, Kenkare says. Some studies suggest that collagen supplements might lead to modest improvements in the integrity of your skin, Zumpano says. But all come with caveats. For example, one 2021 review of 19 studies that included 1,125 people, mostly women, found evidence of reduced wrinkles and improved skin elasticity and hydration in people who took collagen supplements. All the supplements, however, included other ingredients that may have contributed to those results, according to an analysis by dermatologists at Harvard Medical School and Massachusetts General Hospital. Randomized controlled trials that look at effects on skin elasticity, hydration, wrinkles, or other measures tend to be small, they added. Studies of hair and nails are limited. “More research is needed,” Zumpano says. Beyond skin, collagen supplements might help strengthen aging joints, according to growing evidence. Studies in young athletes have linked supplemental collagen with reduced pain and a decline in inflammation, which helps accelerate a return to sports after injuries. To see if the supplement might also help people once they reach middle-age, researchers recruited 86 physically active adults in their 40s, 50s, and 60s for a study published in 2023. For at least six months, participants were assigned to take 10 g of hydrolyzed collagen a day, 20 g a day, or no collagen at all. They didn’t know which group they were in. Compared with the placebo group, people who took collagen supplements reported significantly greater reductions in pain over the study period, especially among those who exercised for more than three hours each week. After the study ended, one participant stopped taking collagen and his pain returned, says lead author Michael Ormsbee, an exercise and nutrition physiologist at Florida State University in Tallahassee. The participant told Ormsbee his pain went away when he started taking the supplement again. The study also linked collagen supplementation with improvements in mood. The mental boost could just be linked to a drop in pain, but the findings echoed evidence of anti-depressant effects in mice taking collagen. That research suggests that collagen can cross the blood-brain barrier. Ormsbee mixes 10 g of hydrolyzed collagen into his coffee every morning. He takes it with 50 milligrams of vitamin C, based on research suggesting that the vitamin helps with collagen absorption. And he follows advice by Keith Baar at the University of California, Davis, whose research suggests taking collagen 30 to 60 minutes before a workout. Researchers are still working out the details of how collagen might help connective tissues and why timing matters. But hydrolyzed collagen is primarily made up of three amino acids that also make up the structure of collagen in our bodies: glycine, proline, and hydroxyproline, Ormsbee says. “When you take it and it's in circulation and then you exercise, you have the best chance of getting those specific amino acids to the tendon or to the ligament or to the joint.” There are other ways to reap the potential benefits of collagen without supplements, experts say. Plenty of foods contain collagen, including meat, chicken, fish, eggs, and bone broth. Zumpano also recommends consuming vitamin C, copper, zinc, and the amino acids proline and glycine to supplement collagen production. Retinoids, ingredients in many anti-aging skin creams, work by increasing collagen production, Kenkare adds. Zumpano suggests eating collagen-rich foods and the nutrients for the body to build its own collagen because “we can't say that the supplement is a cure-all.”