Collagen is a structural protein found in connective tissues throughout your body, including skin, bones, tendons, and ligaments. Its primary function is to help tissues withstand stretching. As we age, our bodies make less collagen. Some people attempt to restore collagen by taking a collagen supplement.
Researchers have investigated the effects of collagen supplementation on aging skin, bone density, joint health, and other factors. While results are promising, more research is needed to fully understand whether or not supplementation is effective.
Despite claims that collagen supplements can firm up your skin, fight age-related damage, boost bone health, and provide other benefits, few rigorous independent studies have tested the effects of these supplements.
Many studies investigating the benefits of marine collagen supplements are small or limited in scope. Also, much of the research is funded by collagen suppliers—large corporations that may serve to benefit from positive outcomes.
Here are some findings from the available research.
Collagen makes up 75% of the dry weight of your skin. As you age, your skin’s inner layer loses collagen and becomes less supple and more vulnerable to damage.
In a 2015 study, scientists evaluated whether or not supplementation could improve the collagen density of skin tissue in a lab setting. Their results suggested that supplements could improve both skin hydration and the dermal collagen network with the potential to improve hallmarks of skin aging.
Other studies have investigated skin elasticity, which starts to decline in our 20s. In a 2014 study in Skin Pharmacology and Physiology, for instance, women aged 35 to 55 years took a specific collagen supplement or a placebo once daily for eight weeks. At the study’s end, those who took the collagen had improved skin elasticity compared to those who took the placebo.
A 2018 study published in Nutrition Research investigated the role of a specific brand of oral collagen supplement that also contained other ingredients (chondroitin sulfate, glucosamine, L-carnitine, vitamins, and minerals). Researchers found that the supplement increased skin elasticity and hydration.
Lastly, a 2019 review of studies investigating oral collagen supplements evaluated their effects on wound healing and skin aging. Study authors concluded the supplements are generally safe and can increase skin elasticity, hydration, density. They added, however, that further studies are needed to determine proper dosing and investigate medical applications.
It is unclear whether collagen supplementation can improve bone health.
In a 2010 study published in the journal Maturitas, researchers found that collagen supplements failed to improve bone health in postmenopausal women. For the study, 71 women with osteopenia were assigned to take either hydrolyzed collagen supplements or a placebo every day for 24 weeks. Results revealed that the collagen supplements did not produce any effects on bone metabolism.