What Is It?
Health Benefits

Dosage Information

Guidelines for Use

General Interaction

Possible Side Effects

Evidence Based Rating Scale


What Is It?

Although biotin is one of the lesser-known B vitamins, it plays an essential role in a number of important body processes. Taking its name from the Greek word bios, meaning "life," this nutrient assists the body in metabolizing Protein, fats, and carbohydrates from food. It plays a special role in enabling the body to use glucose (blood sugar), a major source of energy for the body’s cells. Biotin also helps produce certain enzymes.

Adults rarely suffer from a deficiency of biotin, in part because it's found in so many foods, including rice, barley, oatmeal, whole wheat, soy products, nuts, and mushrooms. Vegetables, with the exception of cauliflower and sea vegetables, do not provide significant amounts. Biotin is water soluble; so the body does not store it. When low levels do occur, problems such as brittle nails and lackluster hair can develop. Scaly dermatitis, especially around the eyes, nose and mouth; lethargy; hallucinations; and numbness or tingling can occur with severe deficiency. (1)

Interestingly, one notable cause of low biotin levels has been linked to the chronic consumption of raw egg whites—“Egg white injury”—which interferes with biotin absorption. (2) It is also seen with long-term anticonvulsant therapy for epilepsy where it can be severe enough to interfere with protein metabolism. (3)

Health Benefits

Biotin has been used to treat hair loss, brittle nails and skin problems, such as eczema. And the role of biotin in lowering blood glucose levels may be beneficial in treating diabetes. 

Specifically, biotin may help to:

Control diabetes. Some evidence indicates that diabetes causes a biotin deficiency. (4) In addition to potentially raising biotin levels, supplementation may actually help to lower blood glucose concentrations. In fact, while this effect has been shown in patients with and without diabetes, the blood glucose levels decrease more drastically in those with diabetes. (5) However, it’s unclear whether biotin as a single agent is effective for this purpose or whether this effect occurs only in combination with other supplements. A 2004 study in 24 patients with type 2 diabetes and 30 non-diabetic subjects found biotin did not produce significant changes in blood glucose or insulin levels in either group of subjects. (6) However, in a small study that combined biotin with chromium picolinate (Diachrome, Nutrition 21), blood glucose and hemoglobin A1c levels were lowered in patients with type 2 diabetes for whom conventional hypoglycemic drugs had not been effective. (7-9) More large, high-quality trials are needed to confirm these preliminary results.

Preliminary evidence also indicates that taking biotin orally or intramuscularly may help to decrease the numbness and tingling associated with peripheral neuropathy in diabetic patients. In a small, two-year trial of three diabetic patients with severe diabetic peripheral neuropathy, high doses of biotin were helpful in preventing and managing peripheral neuropathy. (10) More evidence is needed.

Improve hair problems. A deficiency in biotin can result in thinning of the hair. Replenishing biotin levels might help to slow hair loss, strengthen hair, and stimulate new hair growth. Preliminary evidence indicates that taking biotin in combination with zinc and topical clobetasol propionate (Olux, Temovate) may help to treat hair loss in children with alopecia areata, a condition in which the immune system attacks the hair follicles. (11) However, evidence is limited. Biotin-enhanced shampoos that promote the ability to improve hair problems are available to consumers, but studies have not evaluated the efficacy of these products. More research is needed. 

Strengthen nails. Low levels of biotin can cause nails to become weak and break easily. Preliminary evidence indicates biotin supplementation may help to strengthen brittle nails. In a 1993 study of 35 patients with brittle nails, daily biotin supplementation led to improved nail thickness in 63 percent of patients while 37 percent of patients reported no change in the condition of their nails after supplementation. (12) A 2007 review of vitamins and minerals used for nail health and disease found that taking 2,500 mcg of biotin daily seems to alleviate brittle nail syndrome. (13)

Boost female fertility. Because the B vitamins play a key role in reproductive health and in early fetal development, experts recommend that women trying to conceive take a vitamin B complex supplement that contains biotin, along with vitamin B12, folic acid, and all other B vitamins, plus extra vitamin B6. The role of biotin alone to treat female fertility, however, is not clear. Preliminary studies in animals have shown that biotin deficiency decreases fertility rates, and biotin supplementation seems to improve fertility and viability of eggs. (14, 15) Studies in humans are needed to determine the role of biotin in boosting female fertility.

Prevent seizures.  The B vitamins play an important role in the production of neurotransmitters—brain chemicals that help transmit nerve impulses. In a normally functioning brain, these impulses flow from one nerve cell to another in a controlled manner. In epilepsy, episodes of uncontrolled discharges from many brain cells all at once trigger seizures. Patients on long-term anticonvulsant therapy to treat epilepsy have been shown to have low serum biotin levels. (16) Some anticonvulsants, such as carbamazepine or primidone, may hinder the absorption of biotin in the intestine. (17, 18) Biotin supplementation may help prevent deficiency when using these drugs. (19)


  • capsule
  • intramuscular
  • lozenge
  • tablet 

Dosage Information

For diabetes: 2,000 mcg (2 mg) plus 600 mcg of chromium picolinate (Diachrome, Nutrition 21) daily has been used to maintain healthy blood glucose levels: to treat peripheral neuropathy, 5,000 mcg of oral biotin daily for up to 130 weeks or daily intramuscular treatment for 12 weeks has been used.

For epilepsy: 5,000 to 10,000 mcg daily has been used.

For female fertility: Doses have not been established for humans.

For hair problems: The adequate intake (AI) for biotin is 30 mcg daily for adults. Recommendations for children range from 7 mcg to 25 mcg daily; check with a pediatrician for specific dosages by age and weight.

For nail problems: 2,500 mcg daily has been used.

Guidelines for Use

Most multivitamins and B-complex vitamins contain biotin: it is also available as an individual supplement, primarily in a form known as d-biotin.

General Interaction

  • Persons with diabetes should consult a physician before taking biotin doses greater than 8,000 mcg) as the biotin may alter insulin requirements.

  • Raw egg whites contain a protein that binds to biotin in the intestine and prevents its absorption. Eating two or more uncooked egg whites daily for several months has led to biotin deficiency.

  • Long-term use of antibiotics (particularly sulfa drugs) and of anticonvulsant medications such as carbamazepine (Carbatrol, Tegretol), phenobarbital, phenytoin (Dilantin), or primidone (Mysoline) may decrease biotin levels: they hinder the production of this nutrient in the intestine. 

Note: For information on interactions with specific generic drugs, see our WholeHealthMD Drug/Nutrient Interactions Chart.

Possible Side Effects

Biotin is well tolerated when used at recommended daily dosages of up to 2000mcg orally and 20mg intravenously.


The government has established that most adults over age 18 require 30 mcg of biotin a day. But there is still too little information to determine the safe maximum dose of this Vitamin Consult a physician before taking biotin supplements to treat a specific ailment. 


1. Fugh-Berman A. The 5-Minute Herb and Dietary Supplement Consult. Philadelphia: Lippincott Williams & Wilkins; 2003.
2. Linder MC. Nutritional biochemistry and metabolism, with clinical applications. 2nd ed. East Norwalk, CT: Appleton & Lange; 1999.
3. Mock DM. Biotin. In: Zeigler EE, Filer LJ, eds. Present knowledge in nutrition. 7th ed. Washington, D.C.: International Life Sciences institute Press; 1996.
4. Koutsikos D, Agroyannis B, Tzanatos-Exarchou H. Biotin for diabetic peripheral neuropathy. Biomed Pharmacother. 1990;44:511-4.
5. Coggeshall JC, Heggers JP, Robson MC, et al. Biotin status and plasma glucose in diabetics. Ann N Y Acad Sci. 1985;447:389-92.
6. Baez-Saldana A, Zendejas-Ruiz I, Revilla-Monsalve C, et al. Effects of biotin on pyruvate carboxylase, acetyl-CoA carboxylase, propionyl-CoA carboxylase, and markers for glucose and lipid homeostasis in type 2 diabetic patients and nondiabetic subjects. Am J Clin Nutr 2004;79:238-43.
7. Geohas J, Finch M, Juturu V, et al. Improvement in Fasting Blood Glucose with the Combination of Chromium Picolinate and Biotin in Type 2 Diabetes Mellitus. American Diabetes Association 64th Annual Meeting, June 2004, Orlando, Florida, abstract 191-OR.
8. Singer GM, Geohas J. The effect of chromium picolinate and biotin supplementation on glycemic control in poorly controlled patients with type 2 diabetes mellitus: a placebo-controlled, double-blinded, randomized trial. Diabetes Technol Ther 2006;8:636-43.
9. Albarracin C, Fuqua B, Evans JL, Goldfine ID. Chromium picolinate and biotin combination improves glucose metabolism in treated, uncontrolled overweight to obese patients with type 2 diabetes. Diabetes Metab Res Rev 2007 May 16.
10. Koutsikos D, Agroyannis B, Tzanatos-Exarchou H. Biotin for diabetic peripheral neuropathy. Biomed Pharmacother. 1990;44(10):511-4.
11. Camacho FM, Garcia-Hernandez MJ. Zinc aspartate, biotin, and clobetasol propionate in the treatment of alopecia areata in childhood. Pediatr Dermatol 1999;16:336-8.
12. Hochman LG, Scher RK, Meyerson MS. Brittle nails: response to daily biotin supplementation. Cutis. 1993 Apr;51(4): 303-5.
13. Scheinfeld N, Dahdah MJ, Scher R. Vitamins and minerals: their role in nail health and disease. J Drugs Dermatol. 2007 Aug;6(8):782-7.
14. Bradley JW, Atkinson RL, Krueger WF. Relationship of biotin to reproductive performance of Leghorn-type hens. Poult Sci. 1976 Nov;55(6):2490-2.
15. Landenberger A, Kabil H, Harshman LG, Zempleni J. Biotin deficiency decreases life span and fertility but increases stress resistance in Drosophila melanogaster. Ann Epidemiol. 2004 Oct;15(10):591-600.
16. Krause KH, Berlit P, Bonjour JP. Impaired biotin status in anticonvulsant therapy. Ann Neurol 1982;12:485-486.
17. Krause KH, Berlit P, Bonjour JP. Vitamin status in patients on chronic anticonvulsant therapy. Int J Vitam Nutr Res. 1982;52:375-85.
18. Said HM, Redha R, Nylander W. Biotin transport in the human intestine: inhibition by anticonvulsant drugs. Am J Clin Nutr. 1989;49:127-131.
19. Gaby AR. Natural approaches to epilepsy. Altern Med Rev. 2007 Mar;12(1):9-24.

Evidence Based Rating Scale

The Evidence Based Rating Scale is a tool that helps consumers translate the findings of medical research studies and what our clinical advisors have found to be efficacious in their personal practice into a visual and easy to interpret format. This tool is meant to simplify the information on supplements and therapies that demonstrate promise in the treatment of certain conditions.








Preliminary studies indicate efficacy in lowering blood glucose levels and improving symptoms of peripheral neuropathy. More research is needed. (4-10)

Preliminary evidence indicates potential efficacy to reduce frequency of seizures and maintain biotin levels on anti-convulsant therapy. More research is needed. (16-19
Fertility, female  
Preliminary animal studies indicate potential efficacy. Human studies are needed. (14, 15)

Hair problems  

Preliminary evidence indicates potential efficacy as part of a combination in treating alopecia areata in children. Research is needed on general hair conditions. (11)

Nail problems  
Small studies indicate efficacy in treating brittle nails. More large trials are needed to confirm or refute efficacy. (12, 13)

Date Published: 04/18/2005
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