Collagen is a protein and component in connective tissue in the body, while biotin is a vitamin. Both play important roles in the health of the skin and hair, but it is unclear if either is objectively more helpful for improving their appearance.

Emerging research suggests that taking a collagen supplement may generally improve the appearance of the skin. However, biotin is a vitamin that the human body cannot make on its own, so people must get it from another source.

Taking either substance as a supplement, or getting them from food, may benefit the skin or hair. They are also safe to take together, so people who want to improve skin or health may consider trying both.

Read on to learn more about the differences and benefits of collagen versus biotin.

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Sex and gender exist on spectrums. This article will use the terms “male,” “female,” or both to refer to sex assigned at birth. Click here to learn more.

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Collagen is a protein that helps form the extracellular matrix. This matrix gives skin its shape and structure. The body naturally makes its own collagen, but as a person ages, production slows down. Collagen in the skin begins to break down at a faster rate than the body can produce it.

This can result in the skin losing elasticity and firmness. Loss of collagen plays a role in the development of thinner skin and wrinkles. It may also slow wound healing.

By contrast, biotin is a B vitamin. It is an essential nutrient, but one the body cannot make itself. A person has to get it from food or supplements.

Biotin helps various enzymes metabolize glucose, fatty acids, and the amino acids that build proteins. As a result, a biotin deficiency can lead to hair loss, brittle nails, and skin infections.

Many people take collagen and biotins as supplements to improve skin, hair, and nail health.

One of the key signs of biotin deficiency is hair loss. Supplementing with biotin may reduce hair loss in people with this condition.

Biotin may also work to help regrow hair. For example, in a small 2021 study of 156 females who had weight loss surgery, 72% reported hair loss. 22 people had biotin deficiency and took 1,000 micrograms (mcg) of biotin per day for 3 months. Of these, five people (23%) reported a significant decline in hair loss.

An additional 29 people without biotin deficiency chose to take 1,000 mcg of biotin per day. Of this group, 11 people (38%) reported significant declines in hair loss.

The authors of the study suggest that biotin may improve hair loss in people with and without biotin deficiency, but their study only offers weak evidence for this claim due to its low number of participants.

No recent strong evidence suggests that biotin can make the hair significantly thicker or dramatically reverse hair loss in people who do not have a biotin deficiency. However, supplementing with biotin is unlikely to be harmful if a person takes a supplement at typical levels.

A 2019 randomized placebo-controlled study assessed the effects of a collagen product on skin health in 36 women. All participants were over the age of 35.

Participants used the supplement or placebo for 12 weeks. Researchers then used validated measures of hydration, elasticity, roughness, and density to assess skin health and appearance. The collagen group had significant improvements in all four measures, and these improvements persisted for 4 weeks of follow-up after the initial 12-week period.

However, a collagen nutraceutical manufacturer funded the study. This is a significant limitation that can bias research.

If a person has a biotin deficiency, taking biotin may improve the health of their skin. Otherwise, collagen can be a better option as there is more evidence to suggest it helps improve the skin’s appearance.

A 2019 systematic review of prior studies on oral collagen supplements supports the idea that collagen may improve skin health. The review included 11 studies with 805 participants.

In eight studies of collagen hydrolysate, researchers found evidence that collagen might improve skin aging, cellulite, skin dryness, and ulcers.

Two of the studies found improvements in skin hydration and elasticity with collagen tripeptide, and one found that collagen dipeptide improved the appearance of skin aging proportionate to the quantity of collagen dipeptide a person took.

The analysis reported no adverse events and suggests that collagen could be a useful supplement for reducing the signs of aging.

In contrast, no randomized studies have proven that biotin can improve skin conditions.

Yes. At present, there is no evidence that taking biotin and collagen together is unsafe. For people who want to improve the health of the skin and hair, taking both may be an option.

At typical dosages, biotin and collagen are likely safe.

There is no evidence biotin is toxic at high doses. However, taking biotin at high doses may interfere with some lab tests, including tests for:

  • hepatitis
  • HIV
  • thyroid panels
  • vitamin D
  • b-HCG, which is a hormone present in the blood during pregnancy

A person should tell a doctor about all supplements before having any tests. They may recommend temporarily stopping the supplement until the test is complete.

Collagen naturally exists in the body, so at typical doses, it is unlikely to cause serious side effects. In a small 2019 study of 36 people who took collagen, participants reported no side effects.

The Food and Drug Administration (FDA) does not require companies to test supplements for safety or purity. This means that supplements may contain other ingredients that cause allergic reactions, negative side effects, or that interact with medications.

A person should talk with a knowledgeable doctor before taking any supplements.

A wide range of foods contain biotin, including:

  • eggs
  • meat, such as beef liver and pork chop
  • fish, such as salmon
  • milk
  • almonds
  • whole-wheat bread
  • apples
  • cheddar cheese
  • plain yogurt

Some animal products contain collagen, such as:

  • chicken
  • fish
  • bone broth

A number of plant foods also contain glycine, proline, and hydroxyproline, which are the amino acids that help the body make collagen. Food sources for these amino acids include:

  • nuts
  • legumes
  • seeds
  • soy products

Here are some answers to questions about collagen and biotin.

Can collagen or biotin cause weight gain?

There is no scientific evidence that collagen or biotin causes weight gain.

There are many myths about collagen and biotin on forums, social media sites, and blogs. Some people claim these substances promote weight gain. There is no evidence to support this.

Are there vegan sources of collagen?

Until recent years, there were no vegan collagen options available. However, scientists have found a way to create collagen using genetically modified yeasts and bacteria. Some companies now sell these types of vegan collagen as supplements.

Some vegan foods may also help the body synthesize collagen. These foods include nuts, seeds, legumes, and soy products.

Are there vegan sources of biotin?

Numerous vegan foods contain biotin. They include nuts, seeds, sweet potatoes, apples, broccoli, and spinach. People taking biotin supplements should read the label to assess whether the product is vegan.

Collagen and biotin both play a role in human health. Collagen is an important component in connective tissue, including the skin. Biotin is a mineral that the body needs in order to metabolize fatty acids and amino acids, which are the building blocks of protein.

Biotin deficiency can cause skin rashes and hair loss, so people with this condition may benefit from taking it as a supplement. Limited evidence suggests it may help with hair loss even in those without a biotin deficiency, but more research is necessary to confirm this.

Collagen loss occurs naturally with age and causes a loss of skin elasticity and density. Whether collagen or biotin is better for a person will depend on their individual circumstances and aims.

Hair loss and skin health issues can signal an underlying health problem. Before trying a supplement, a person should talk with their doctor.