The Health Benefits of Biotin

A vitamin believed to stimulate hair growth and reverse hair loss

Biotin (vitamin B7) is an essential micronutrient that's important for energy production and other functions in your body. It is found in foods like oats and egg yolks, and can also be taken in supplement form.

Biotin supplements and shampoos are often promoted for improving hair health and regrowing lost hair. However, research suggests they're only effective in people whose hair problems are caused by a biotin deficiency.

This article discusses the possible benefits of biotin for your health and hair, its possible side effects and safety information, the proper dosage, and how to select the right biotin product for you.

biotin-rich foods

Verywell / JR Bee

What Is Biotin?

Biotin is an essential vitamin—meaning your body needs it to function properly but doesn't produce it on its own. You need to get biotin from your diet or supplements.

Biotin helps your body:

  • Turn dietary protein, carbohydrates, and fat into energy
  • Regulate signals sent by your cells
  • Regulate the activity of your genes

Biotin is available in many common foods and you don't need a lot of it.

Biotin Supplement Benefits

Biotin is often mentioned in the context of hair loss treatment. Despite this, research backing up such a benefit is scant. The same goes for other possible benefits of biotin.

Where biotin supplementation is likely effective is in the treatment of biotin deficiency. This, however, is rare in the United States.

If you're not deficient in biotin, taking a supplement would likely offer no benefits.

Hair Growth

Some proponents claim that biotin-containing products can make your hair thicker, stronger, shinier, and more voluminous. Science doesn't support these claims.

A handful of research studies have shown that biotin supplementation may help stimulate hair regrowth in people who have a clinical biotin deficiency or alopecia (hair loss).

In people with temporary hair loss, studies have shown that supplements containing biotin significantly improved hair growth after 90 days. Some case reports suggests biotin supplementation is beneficial for people who have an underlying medical condition causing their hair to thin.

Even so, researchers also note that hair regrowth is often caused by many factors and may not be due to biotin supplementation at all.

Other Purported Benefits

Other possible benefits of biotin include treating:

However, the evidence that biotin can treat any of these conditions is insufficient.

Do You Need More Biotin?

Though biotin deficiency is not common in the U.S., it does occur. Certain health conditions, medications, and lifestyle choices can make someone prone to a deficiency.

A healthcare provider can diagnose a biotin deficiency with lab work. Biotin supplementation and/or dietary increases may be an important part of correcting the deficiency.

Symptoms of Biotin Deficiency

Symptoms of a biotin deficiency include:

  • Thinning hair
  • Brittle nails
  • Dry skin
  • A red, scaly rash, usually around the eyes, nose, and mouth
  • Conjunctivitis (pink eye)
  • Depression
  • Exhaustion
  • Hallucinations
  • Numbness and tingling in your arms and legs

If you notice any symptoms of biotin deficiency, see your healthcare provider for a diagnosis. Many other things can cause similar symptoms but require different treatments.

Causes and Risk Factors

You are more likely to experience biotin deficiency if you:

  • Consume a lot of raw egg whites, such as in smoothies: Uncooked eggs contain a protein called avidin, which blocks the absorption of biotin.
  • Have inflammatory bowel disease or other conditions involving an imbalance of intestinal bacteria
  • Drink a lot of alcohol or have cirrhosis (a liver disease often related to alcohol)
  • Have the rare genetic disorder biotinidase deficiency, which prevents biotin absorption

Medications that can lead to biotin deficiency include:

  • Beta-blockers (blood pressure medications)
  • Blood thinners
  • Anticonvulsants (seizure/epilepsy medications)
  • Retinoids (topical medications for acne and reducing wrinkles)

Click Play to Learn More About Biotin Hair Growth

This video has been medically reviewed by Casey Gallagher, MD.

Possible Biotin Side Effects

Biotin supplements can cause problems if you take too much. Side effects of biotin can include: 

  • Trouble sleeping
  • Skin rashes
  • Digestive upset
  • Problems with insulin release
  • Kidney problems

According to a report published in the New England Journal of Medicine, biotin treatment was said to interfere with laboratory tests and mimic Graves' disease—a condition that causes the thyroid to produce too much thyroid hormone.

As with any supplement, the safety of long-term or high-dose use isn't known. Always check with your healthcare provider before starting a supplement regimen.

Dosage and Safety

The Food and Drug Administration (FDA) has not established a recommended dietary allowance (RDA) for biotin.

According to the National Institutes of Health (NIH), 30 micrograms (mcg) is the adequate daily intake for adults 19 years of age and older. People can usually get this amount through their diet.

Still, people who support its use often recommend taking 2 to 5 milligrams (mg) of biotin in supplement form daily in order to strengthen hair and achieve results.

Although biotin is a water-soluble vitamin (meaning any excess comes out in your urine and feces), the safety of using any amount of biotin in supplement form is unknown.

As with many other supplements, biotin hasn't been tested for safety:

  • During pregnancy and breastfeeding
  • In children
  • In people with chronic conditions
  • In people taking medications

Don't take biotin supplements in lieu of getting medical attention. That can cause dangerous delays in getting a proper diagnosis and treatment.

What to Look For

Bacteria in the intestines usually provide more than the body's daily biotin requirements, and many foods contain biotin as well.

If you're diagnosed with a deficiency, you can correct it with supplements, a biotin-rich diet, or both.

Biotin Supplements

In the United States, supplements are largely unregulated and aren't always tested for quality. That means the content of a product may not match what's on the label.

To ensure you're getting what's on the label, look for supplements that have been voluntarily submitted for testing by an independent certifying body such as:

  • U.S. Pharmacopeia (USP)
  • ConsumerLab
  • NSF International

Certification means the label is correct and the product isn't contaminated. It doesn't guarantee safety or effectiveness. Always talk to your healthcare provider before taking a new supplement.

Biotin-Rich Foods

Food sources of biotin (in micrograms per 100 grams) include:

  • Cooked egg yolks (53)
  • Oats (27.0)
  • Wheat germ (17.0)
  • White mushrooms (16)
  • Spinach (6.9)
  • Cheese, brie (6.2)
  • Milk (3.5)
  • Pork (5.0)
  • Carrot (5.0)
  • Apple (4.5)
  • Tomato (4.0)
  • Beef (3.0)
  • Chicken (2.0)
  • Lettuce (1.9)


There's not enough evidence to prove that biotin supplements are safe or effective for hair thinning or loss.

If you're concerned about your hair health for any reason, talk to your healthcare provider. In most cases, the best way to prevent hair loss is to treat the underlying condition causing it. If you have a biotin deficiency, you can correct it through diet or supplements.

Frequently Asked Questions

  • Does biotin help hair to grow faster?

    It depends. Research suggests that biotin can stimulate hair regrowth in people who have a clinical biotin deficiency. There is no evidence to show biotin can improve hair growth in people without nutritional deficiencies.

  • Can biotin cause a rash?

    Yes, applying a biotin product or taking a supplement can cause skin irritation and rashes in people who are sensitive to the B vitamin or other ingredients. Taking too much biotin can also cause a skin rash. People with sensitive skin should do a patch test on their inner arm before applying biotin to a larger area.

  • Does biotin cause weight gain?

    No, there is no evidence to suggest taking biotin supplements can lead to weight gain. In fact, biotin is sometimes touted as a weight-loss supplement. However, there is no research to support this use.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Ablon G. Clinical study a 3-month, randomized, double-blind, placebo-controlled study evaluating the ability of an extra-strength Marine protein supplement to promote hair growth and decrease shedding in women with self-perceived thinning hair. Dermatol Res Pract. 2015;2015:1-8 doi:10.1155/2015/841570

  2. Patel DP, Swink SM, Castelo-Soccio L. A review of the use of biotin for hair loss. Skin Appendage Disord. 2017;3(3):166-169. doi:10.1159/000462981

  3. Réhault-Godbert S, Guyot N, Nys Y. The golden egg: Nutritional value, bioactivities, and emerging benefits for human healthNutrients. 2019;11(3):6. doi:10.3390/nu11030684

  4. Agrawal S, Agrawal A, Said HM. Biotin deficiency enhances the inflammatory response of human dendritic cellsAm J Physiol Cell Physiol. 2016;311(3):386-391. doi:10.1152/ajpcell.00141.2016

  5. Phillips TG, Slomiany WP, Allison R. Hair loss: Common causes and treatment. Am Fam Physician. 2017;96(6):371-378.

  6. Kummer S, Hermsen D, Distelmaier F. Biotin treatment mimicking Graves' disease. N Engl J Med. 2016;375(7):704-706. doi:10.1056/NEJMc1602096

  7. National Institutes of Health, Office of Dietary Supplements. Biotin.

Additional Reading

By Cathy Wong
Cathy Wong is a nutritionist and wellness expert. Her work is regularly featured in media such as First For Women, Woman's World, and Natural Health.