The Difference Between Collagen, Keratin, and Biotin—And Which Is Best For You

Collagen, keratin, and biotin are three popular supplements often hailed for their health and beauty benefits, particularly related to hair, skin, nails, and healthy aging. Each of these supplements serves unique functions in the body, making them suitable for a variety of health and beauty goals, whether it’s protecting skin’s firmness, supporting healthy hair, or keeping joints feeling strong and mobile. 

If you’re curious about adding collagen, keratin, or biotin to your routine, you’re far from the only one. Collagen supplements alone are a nearly $10 billion industry! But which one (or combination) is the best fit for your routine? Here’s a breakdown of these nutrients, how they function in the body, their potential benefits, and how to incorporate them into your diet and supplement regimen for the greatest impact.

• ABOUT OUR EXPERTS: Dr. Joshua Axe, D.N.M., C.N., N.M.D., a doctor of natural medicine, nutritionist, co-founder of Ancient Nutrition, and member of The Vitamin Shoppe Wellness Council. Bonnie Taub-Dix, R.D.N., is a registered dietitian and host of the Media Savvy Podcast. Melissa Levin, M.D., is a clinical instructor at Mount Sinai Icahn School of Medicine and dermatologist at Marmur Medical in New York. Karen Linardakis-Cooney, B.C.H.H.P., C.N., is a board-certified holistic health practitioner and nutritionist with The Vitamin Shoppe. 

Collagen: The Building Block of Youthful Skin and Joints

Collagen is the most abundant protein in the human body, found in bones, muscles, skin, and tendons, explains Dr. Joshua Axe, D.N.M., C.N., N.M.D., a doctor of natural medicine, nutritionist, co-founder of Ancient Nutrition, and member of The Vitamin Shoppe Wellness Council. It essentially acts as a “glue” that helps hold the body together and provides structure, he says.

Potential Benefits of Collagen

In the body, collagen helps to maintain the integrity of cartilage and the cushioning between bones (among other things), making it essential for joint health and mobility, according to Axe. 

It also benefits the skin in a couple of ways. “Collagen helps to restore the skin’s moisture balance and improves elasticity and texture, making it an invaluable supplement as you age,” Axe suggests. Collagen supplementation has been shown to ward off wrinkles and dryness. 

“Collagen is important at any age, but it’s particularly relied upon by older adults and those experiencing changes in various parts of their bodies, like their skin and joints,” agrees registered dietitian Bonnie Taub-Dix, R.D.N., host of the Media Savvy Podcast.

Not to mention, collagen also plays a meaningful role in supporting healthy digestion and gut function by promoting the integrity and function of the intestinal lining, making it a powerful potential ally for those experiencing issues like leaky gut, Axe adds.

Collagen Sources 

Collagen comes from animal sources, particularly from the bones, skin, and connective tissues of cattle, fish, chickens, and pigs. Although many modern foods don’t offer much collagen, you will find some in fish and chicken. The real jackpot here, though, is bone broth, which is made by simmering animal parts—namely bones and joints—that naturally contain collagen, according to Axe. He recommends drinking bone broth regularly because of its rich supply of collagen and minerals.

These days, many people obtain collagen through powdered collagen supplements, such as collagen peptides powders.

Also worth noting: “Some dermatologists believe that eating foods that are high in the building blocks of collagen, including amino acids like proline and lysine, and minerals like copper, can help improve your skin,” explains Melissa Levin, M.D., clinical instructor at Mount Sinai Icahn School of Medicine and dermatologist at Marmur Medical in New York. Shellfish, nuts, and red and lean meats are all sources of copper; legumes and lean meats are good sources of lysine; and egg whites, meats, cheese, and soy all contain proline.

While collagen isn’t found in plant foods, plenty of nutrients found in plant foods support the body’s collagen production, including vitamin C and zinc, so consuming plant foods that provide these—like leafy greens, legumes, berries, and citrus fruit—is definitely a good move, says Taub-Dix. Vitamin A, found in sweet potatoes, carrots, and spinach, is another supporter of collagen production, Levin adds. 

Supplementing With Collagen

“As we age, we produce less collagen, which results in loss of elasticity and volume, and the onset of wrinkles,” says Levin. Preliminary studies suggest bioactive collagen peptide supplements show promise here. One study published in Skin Pharmacology and Physiology found that 2.5 grams of bioactive collagen peptide daily reduced the appearance of wrinkles around the eyes in women ages 45 to 65 after eight weeks.

Of course, you might also choose to try out a collagen supplement to support your joints—or even your gut health. 

To get the most from collagen supplements, Axe suggests seeking out hydrolyzed collagen peptides, which contain collagen that’s been broken down into smaller units that are easiest to digest and utilize. This is particularly helpful if you struggle with gut issues. 

Read More: 8 Ways To Enjoy Bone Broth—Because It’s SO Good For You

Collagen powders are easy to incorporate into your daily routine, too. “Adding collagen powder to your morning coffee or smoothie can kickstart your day with a boost of protein that supports skin, joint, muscle, and gut health,” Axe says. Since these powders are basically tasteless, they blend well into all sorts of foods and drinks, including oatmeal, yogurt, baked goods, and more. 

How much collagen should you consume? “The suggested daily intake of collagen varies; generally, doses range anywhere from 2.5 to 15 grams per day,” says Karen Linardakis-Cooney, B.C.H.H.P., C.N., a board-certified holistic health practitioner and nutritionist with The Vitamin Shoppe. 

Keratin: For Strong, Healthy Hair

Keratin is a protective protein and the key structural material of the outer layer of human skin, according to Taub-Dix. It’s also the primary component of hair and nails. In fact, it’s the protein credited for giving hair its thickness and strength. Additionally, “keratin is found on cells in the lining of organs, glands, and other body parts,” she notes.

Potential Benefits Of Keratin

Keratin’s primary function is to protect and strengthen your hair, skin, and nails against external damage, hence why so many people seek it out in supplement form if they’re not feeling great about the quality or health of these parts, says Taub-Dix. Given its presence internally, it seems to play a protective role for many organs, as well.

You’re likely most familiar with keratin hair treatments (used to make hair smoother and shinier) offered at many salons, but some research suggests taking keratin (specifically keratin hydrolysate) orally may have beauty benefits. One recent study published in Journal of Cosmetic Dermatology found that women who supplemented with keratin for 90 days experienced positive changes in their complexion, hair, and nails—specifically regarding skin roughness, elasticity, and moisturization, appearance of wrinkles, nail hardness, and hair glossiness. 

While keratin may be worth a try at any age, particularly if your hair, skin, and nails look and feel lackluster, it could be exceptionally helpful as you get older. “Keratin production declines with age,” notes Taub-Dix. “This can result in changes in your hair and nails over time.” 

Keratin Sources

“The body naturally produces keratin, an effort you can support by eating plenty of high-quality protein,” Taub-Dix says. She recommends prioritizing protein sources such as meat, poultry, eggs, fish, legumes, and beans. 

“You need enough protein in your diet to produce and maintain your hair’s strength,” Axe agrees. He recommends aiming for about 20 to 30 grams of protein per meal to ensure you’re hitting the mark. Otherwise, “be sure you get enough iron, vitamin E, and trace minerals like selenium, copper, and magnesium, which also encourage healthy hair,” he adds.

Of course, if you’re not thrilled with how your skin, hair, or nails look or feel, you can always look for a keratin product to support their strength and resilience, suggest Taub-Dix.

Supplementing With Keratin

If you’re looking to ramp up the keratin in your life, you can take a couple of approaches.

For those with hair damage from chemical processes or excessive styling, topical keratin treatments can help repair and restore hair’s luster and strength, according to Cooney. For example, keratin-enhanced hair-care products like shampoos, hair masks, and conditioners can help smooth frizz, increase shine, and strengthen hair by filling in porous strands, she says.

Oral supplements containing keratin are also popular options for more widespread benefits. Typically available in capsule and powder form, many of these supplements combine keratin protein with other nutrients like vitamin C, zinc, other antioxidants, and collagen that support healthy hair, Cooney says. There’s no standard dosage here, though research suggests both 500 and 1,000 milligrams of keratin hydrolysate per day is effective.

Biotin: The Beauty Vitamin

Also known as vitamin B7, biotin is an essential nutrient that aids in the metabolism of fatty acids, glucose, and amino acids, explains Cooney. “Biotin also helps the body make keratin, contributing to hair strength and promoting hair growth and thickness,” she says.

Potential Benefits of Biotin

Biotin’s role in keratin production makes it a potentially valuable supplement for promoting the strength and growth of hair and nails, according to Taub-Dix. It’s often recommended for people experiencing hair thinning as it may help support regrowth and follicle strength, she says.

Biotin’s potential hair and nail benefits may also stem from its role in energy production. “Biotin and other B vitamins are needed to convert the food you eat into usable energy,” says Axe. Your body needs ample energy for every process it performs, maintaining healthy locks and nails, included. Biotin, in particular, is also important for cell growth.

Perhaps unsurprising: Biotin deficiency is often identified by brittle hair and nails, notes Levin.

It’s worth noting that study results on biotin supplementation for hair have been mixed. However, “Several studies, including one published in Dermatology Research and Practice and another in the Journal of Clinical and Aesthetic Dermatology, suggest that supplementing with biotin and increasing intake from your diet can help promote hair growth and fullness in about three to six months,” shares Axe. 

Read More: The Top Causes Of Hair Loss In Women

Perhaps this vitamin’s biggest claim to fame, though, is supporting healthy nails. One well-known study, published in Cutis, for example, found that 63 percent of participants with brittle nails saw improvement in nail plate thickness after six months of biotin supplementation.

Biotin Sources

While there isn’t a standard recommended intake of collagen and keratin, there is one for biotin: 30 micrograms per day, according to the National Institutes of Health. The best way to meet your needs? A varied diet containing lots of whole foods.

Since this vitamin is water-soluble, meaning the body does not store it, you need to regularly replenish it via your eats. Thankfully, that’s pretty easy to do considering biotin is found in a wide variety of foods, including eggs (particularly egg yolks), organ meats, dairy products, nuts, seeds, sweet potatoes, bananas, and leafy green vegetables, Taub-Dix says. 

Supplementing With Biotin

In addition to eating biotin-containing foods, you can also take the B vitamin as a supplement, most often in capsule form. “You’ll find biotin in many beauty products and supplements, particularly those geared towards people experiencing thinning hair and brittle nails,” Taub-Dix says. 

Biotin supplements typically contain much higher amounts than the RDA. “Dosages often range from 1,000 to 10,000 micrograms,” shares Axe. 

These potent doses aren’t an issue for most people; however, people prone to breakouts might want to be mindful. “Both biotin and pantothenic acid (vitamin B5) are absorbed through the same intestinal receptors,” explains Levin. “If someone takes an excess amount of biotin, the biotin can saturate these receptors and inhibit B5 absorption. Since B5 plays a role in skin barrier function, hindered absorption may spur worsening breakouts.”

The Bottom Line: Should You Take Collagen, Keratin, or Biotin (Or All Three)?

If you’re looking to improve skin elasticity, gut function, and joint health, collagen may be your best bet. Meanwhile, for those focused on hair and nail health, keratin and biotin supplements can both provide benefits. Whichever you choose, all three are low-risk options that can likely help you to look and feel your best. In many cases, you may choose to try all three for overall beauty perks; many supplements—like The Vitamin Shoppe Keratin for Hair with Biotin and Collagen—are formulated to provide all of these powerhouses in one fell swoop!