Since collagen is the body’s most abundant protein and found in connective tissues, joints, and skin, we’d say it’s a pretty big deal.* But what exactly does collagen supplementation do for your mane? After all, hair is made of the protein keratin—not collagen. Well, we tapped some top experts to get the scoop on collagen and hair health including what collagen does for the hair, what to look for in a hair supplement, and whether it can, in fact, help with hair growth.* Keep reading to learn more. There’s pretty substantial evidence in connection with the skin and joints, and increasing studies about bone, muscles, and gut health.* However, one area of research that’s not as vast is hair health. (It’s just not a top priority for researchers at the moment, but that doesn’t mean that down the line there won’t be more.) That being said: We found four potential benefits collagen has on hair, including reducing hair shedding and a balanced scalp.* More on this below. Certified trichologist and founder of Advanced Trichology William Gaunitz, FWTS, says the primary amino acid that is most helpful is called proline1. It’s a physical component of keratin and affects new hair growth. So, in short, collagen peptides that contain proline can help create the protein that makes hair and supports growth.* mbg’s vice president of scientific affairs Ashley Jordan Ferira, Ph.D., RDN, provides this pragmatic tip: “Check out the collagen brand’s amino acid profile to see the breakdown of these protein building blocks with more transparency. This will inform proline percentage and all the other amino acid contributions too.” And as the hair follicle goes into the catagen stage, it sheds two layers of collagen encompassing it. “As our bodies create more collagen, the layers regenerate. This supports our hair follicles by assisting them in re-entering the anagen phase and maintaining the hair growth cycle,”* she says. Gaunitz also adds that the consumption of collagen allows the body to have a greater number of available amino acids, which can help strengthen the protection of hair follicles from oxidation.* This, in turn, will improve the productivity of the hair follicle.* “It’s full of antioxidant properties that can help neutralize free radicals2 from UV rays and pollution,”* she says. “It is also theorized that collagen may help protect hair follicles and decrease graying of hair as well."* More research to aid this theory: One study found that free radical accumulation in the hair can manifest in loss of color3, or hair graying. Hair graying is, of course, a natural part of the aging process, but this loss of pigment speeds up in correlation to the amount of oxidative stress the hair follicle is exposed to. However, this is just a theory at this point. No study has confirmed this at this time. She continues that this suboptimal structural support may contribute to hair loss. And since a healthy scalp is the foundation for healthy hair and hair growth, we consider collagen a major factor when it comes to scalp health.* We recommend making sure you get a robust amount of nutrients in your diet—from food and supplementation—in order to optimize your results. So, here are a few other recommendations: Most experts agree that there isn’t enough research to prove one is better than the other when it comes to the hair. Collagen helps hair in the ways we suggested above, and biotin is thought to support healthy hair growth because it is involved in the production of keratin9.* Ferira shares that, “the collagen-versus-biotin competitive sentiment is invented by humans. In reality, this protein and water-soluble vitamin are not going head to head. They each deliver unique health functions relevant to the beauty realm.” So certainly, you can try both, since biotin and collagen come with a load of beauty benefits including improving skin, nail, and hair health.* Gaunitz says if you choose to take collagen or biotin to improve hair growth, it’s best to combine it with vitamin C10, which will enhance its antioxidant capabilities.* And one way you can get those amino acid peptides is through collagen supplementation.* If you are looking for a new option, check out our favorite collagen supplements here.