The Health Benefits of Biotin

Believed to stimulate hair growth and reverse hair loss

Biotin is a B vitamin often recommended for hair health. Since biotin deficiency can lead to thinning of the hair, proponents claim that taking biotin supplements—in pill or tablet form—or using biotin-enriched shampoo and hair products can thicken hair and stimulate hair and nail growth.

Health Benefits

Biotin is an essential vitamin—meaning that your body needs this micronutrient to function properly. The biotin you consume in foods helps your body to turn the food you eat (protein, carbohydrates, and fat) into energy.

biotin-rich foods
 JR Bee / Verywell 

Taking a biotin supplement is likely effective for treating biotin deficiency. But many health products boost other health claims related to biotin supplement consumption and many of these health benefits have not been supported by scientific evidence.

Hair Growth

So does taking a biotin supplement make your hair grow faster or fuller? There isn't enough evidence to rate biotin's effectiveness in the treatment of hair loss, according to the National Institutes of Health (NIH).

Manufacturers claim that shampoo, conditioner, and hair oils, masks, or creams containing biotin can thicken hair, increase fullness, and add shine. Despite these claims, there are no scientific studies to show that biotin shampoo or any other hair product can make your hair grow faster or thicker.

Other Benefits

Other possible benefits of biotin include the treatment of:

  • Brittle finger or toenails
  • Diabetes
  • Diabetic nerve pain
  • Muscular sclerosis
  • Diabetic nerve pain

Note: There is insufficient scientific evidence to know for sure if biotin can treat any of these conditions.

Possible Side Effects

Biotin supplements can cause problems if you ingest too much. Side effects can include skin rashes, digestive upset, problems with insulin release, and 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. As with any supplement, the safety of long-term or high-dose use isn't known. 

Dosage, Preparation, and Safety

The U.S. Food and Drug Administration (FDA) has not established a recommended dietary allowance (RDA) for biotin. According to the Food and Nutrition Board of the Institute of Medicine, 30 mcg is the daily adequate intake for adults 19 years of age and older, which can usually be achieved through dietary consumption.

Although there is no recommended dietary allowance for biotin, proponents often recommend taking 2 to 5 mg (2000 to 5000 mcg) of biotin in supplement form daily in order to strengthen hair shafts and achieve results.

Although biotin is a water-soluble vitamin (the excess is excreted in urine and feces), there is no evidence to support this recommendation and the safety of regular use of this amount isn't known.

As with other supplements, biotin hasn't been tested for safety in pregnant women, nursing mothers, children, and those with medical conditions or who are taking medications. You can find out more about how to use supplements safely here.

Deficiency

Biotin deficiency can occur in people who drink alcohol excessively or consume a great deal of raw egg white (which contains avidin, a protein that blocks the absorption of biotin). Two or more uncooked egg whites daily for several months has been known to result in biotin deficiency.

Genetic disorders of biotin deficiency (such as biotinidase deficiency), renal dialysis, and smoking may also increase your need for biotin. Since biotin is produced in the intestines, people with inflammatory bowel disease or other conditions that can disrupt the balance of bacteria in the intestines may not be able to adequately produce biotin.

If you notice any symptoms of deficiency, consult your health care provider. Symptoms include:

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

What to Look For

It is likely that you get enough biotin naturally in the food you consume. Biotin deficiency is believed to be uncommon. Bacteria in the intestines usually provides more than the body's daily requirements and biotin is also in a variety of common foods. 

Most people can meet their daily biotin needs by consuming biotin-rich foods like bananas, carrots, cooked egg yolks, sardines, nuts, legumes, brewer's yeast, nutritional yeast, liver, cauliflower, salmon, and mushrooms.

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)

Other Questions

What can I do about thinning hair?

Thinning hair and hair loss can be very distressing. If you've noticed that you're losing your hair or that your hair is thinning (called pattern hair loss) and hormone imbalances (such as thyroid troubles), it's important to see your healthcare provider to determine the cause.

Will a supplement help what I think is a deficiency?

Although you may be eager to halt the hair loss, taking biotin tablets or supplements without being properly assessed by a physician poses the risk that diagnosis and treatment of the underlying cause will be delayed. 

Although biotin deficiency is considered rare, it can result in hair loss that can be addressed with supplementation. If you have symptoms of biotin deficiency or are thinking of taking it, be sure to talk with your healthcare provider to assess your levels and discuss what's best for you.

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Article 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. 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

  2. Kummer S, Hermsen D, Distelmaier F. Biotin Treatment Mimicking Graves' Disease. N Engl J Med. 2016;375(7):704-6. doi:10.1056/NEJMc1602096

  3. Mock DM, Quirk JG, Mock NI. Marginal biotin deficiency during normal pregnancy. Am J Clin Nutr. 2002;7. doi:10.1093/ajcn/75.2.295

  4. Zempleni J, Hassan YI, Wijeratne SS. Biotin and biotinidase deficiency. Expert Rev Endocrinol Metab. 2008;3(6):715-724. doi:10.1586/17446651.3.6.715

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

Additional Reading
  • Daniells S, Hardy G. Hair loss in long-term or home parenteral nutrition: are micronutrient deficiencies to blame? Curr Opin Clin Nutr Metab Care. 2010 Nov;13(6):690-7.
  • Kummer S, Hermsen D, Distelmaier F. Biotin Treatment Mimicking Graves' Disease. N Engl J Med. 2016 Aug 18;375(7):704-6. 
  • Rajput RJ. Controversy: is there a role for adjuvants in the management of male pattern hair loss? J Cutan Aesthet Surg. 2010 May;3(2):82-6.
  • Trüeb RM. Serum Biotin Levels in Women Complaining of Hair Loss. Int J Trichology. 2016 Apr-Jun;8(2):73-7.