Common Names

  • Vitamin H
  • Vitamin B7
  • Coenzyme R
  • D-Biotin
  • W Factor

For Patients & Caregivers

How It Works

Biotin is widely available in foods. Biotin supplements are used to promote nail, skin, and hair health, but evidence is limited. Some people also use it for nerve, muscle, and diabetic symptoms. Patients should discuss use of this supplement beforehand with their doctor.

Biotin is an important coenzyme involved in sugar and fat metabolism. It is found in a variety of foods such as meat, vegetables, and eggs, and is also made in the intestines by bacteria.

Some studies show that taking biotin can benefit patients with multiple sclerosis or may improve diabetic nerve pain. Patients with diabetes may have a greater chance of being biotin-deficient. Consuming large amounts of egg whites or taking epilepsy drugs may also lead to biotin deficiency. However, there is no evidence for using biotin supplements in general, and deficiency in this nutrient is otherwise quite rare. In addition, too much biotin may weaken immune response and reduce the number of white blood cells. It may also cause inaccurate lab test results. Therefore, patients should consult with their doctor to determine the source of a true deficiency, or to discuss proper use of this supplement.

Purported Uses
  • To treat multiple sclerosis Preliminary data from a long-term study suggests that biotin is safe and may reduce symptoms in some patients. However, this study is ongoing and the final result is still not known.
  • To treat diabetic peripheral neuropathy A small clinical study supports this claim. Larger studies are needed to confirm the effects.
  • To treat brittle nails A small survey indicates that biotin may be effective. Further studies are needed.
  • To treat hair loss Evidence is limited. According to one study, some women with hair loss may have lower biotin levels in their blood, but this does not mean it is the cause of it. In addition, there may be more than one cause. It is unclear if biotin is effective in preventing or treating hair loss in otherwise healthy people or in cancer patients due to chemotherapy.
  • To treat infantile seborrheic dermatitis (a skin disorder) A small study showed that biotin was not effective in treating itchy, scaly skin.
Patient Warnings
  • Taking high doses of biotin can incorrectly affect the results of many types of lab tests, including some used to detect heart or thyroid disease. It may also produce invalid results with some types of pregnancy tests. Therefore, it is important to tell your healthcare provider about any use of biotin supplements.
Do Not Take If
  • You are undergoing lab tests such as blood or thyroid tests: There have been cases of biotin supplementation causing inaccurate test results. Therefore, it is important to tell your healthcare provider about any use of biotin supplements.
  • You are taking a pregnancy test: Taking biotin supplements may cause an invalid test result.
Side Effects

Taking biotin supplements can interfere with certain lab tests. This may result in the masking of disease states, inaccurate measures of response to therapies, or unnecessary diagnostic procedures. Therefore, it is important to tell your healthcare provider about any use of biotin supplements.

Special Point
  • Consumers may be unaware that biotin is also included in many commercially available multivitamin supplements. 
Back to top

For Healthcare Professionals

Scientific Name
Cis-hexahydro-2-oxo-1H-thieno[3,4-d]-imidazole-4-valeric acid
Clinical Summary

Biotin is an essential B vitamin that acts as an important coenzyme in carbohydrate and lipid metabolism. It is often taken alone or in combination with other vitamins for skin, nail, and hair health. It is also thought to help diabetes and neuromuscular disorders.

A small study suggests biotin supplementation may be effective in strengthening brittle nails (3). Low serum biotin levels have been associated with hair loss in some women but causes may be multifactorial (16), and evidence is limited  (23) (24).

Other preliminary data suggest that high-doses of biotin may decrease symptoms of multiple sclerosis (17). Biotin may benefit patients with severe diabetic peripheral neuropathy (4). When taken with chromium, it may improve glycemic control in patients with type 2 diabetes (5). There are reports that biotin can reduce skin rash from gefitinib or erlotinib (18), but it did not reduce seborrheic dermatitis in infants (2). More studies are needed to confirm these observations. There is also not enough evidence to show that biotin is effective in preventing or treating chemotherapy-induced hair loss.

Biotin is abundant in foods including meat, vegetables, and eggs. True deficiency is rare but can be caused by a genetic disorder (13) or by malabsorption syndromes. Long-term use of certain anticonvulsant drugs can also induce biotin deficiency (11). These conditions can be treated by biotin supplementation. 

Although biotin is generally safe, there are reports of interference with lab assays when taken in high doses (19) (20). In some hCG tests, biotin supplementation may also cause invalid test results (25). Surveys suggest that biotin supplement use is prevalent (26) (27), yet users may not report improvements in the condition they took it for, and lack awareness of potential lab test interference with use of this supplement (27).

Food Sources

Liver, kidney, eggs, almonds, sweet potato, soy beans, peanuts, wholegrain cereals, brewer’s yeast, dairy products

Purported Uses
  • Acne
  • Brittle nails
  • Dermatitis
  • Diabetic neuropathy
  • Hair loss
  • Multiple sclerosis
Mechanism of Action

Biotin is an essential part of carbohydrate and lipid metabolism via carboxylase. It is converted into the free active form by the enzyme biotinidase, and can be synthesized in the intestine by bacteria (1).

Biotin induces microtubule formation in neurons (7), and biotin deficiency slows myelination (8) which may result in neuropathy. Biotin may reduce the activity of interleukins and interferons, and reduce the number of leukocytes (9).

Adverse Reactions

Although biotin is generally safe, there have been cases of biotin supplementation interfering with certain lab tests, which may mask disease states, overestimate response to therapies, or subject patients to additional unnecessary diagnostic procedures (29).

Case Reports

Missed diagnosis of heart disease due to high intake levels of biotin: A patient death was related to falsely low troponin test results that were due to the patient’s high intake levels of biotin (22). Other papers also report the susceptibility of cardiac troponin assays to biotin interference at levels achievable with over-the-counter supplements (28).

Herb Lab Interactions

Immunoassay interference caused by high-dose biotin supplementation: Incorrect test results during routine follow-up of a 54-year-old female patient with progressive multiple sclerosis and Hashimoto’s thyroiditis (29).

Inaccurate troponin test results (22): A patient death was related to a missed diagnosis of heart disease, stemming from falsely low troponin test results that were due to the patient’s high intake levels of biotin. Other papers also report the susceptibility of cardiac troponin assays to biotin interference at levels achievable with over-the-counter supplements (28)

Multiple blood test results  (20) (22): Biotin supplementation can affect various test results.

Free Thyroxine and Thyroid Stimulating Hormone (FT4/TSH) assay: Reported false-high values were attributed to high serum biotin levels in a neonate (12).

Qualitative urine hCG tests: Biotin supplementation may cause an invalid test result with some types of pregnancy tests due to absence of a control line (25).

Other immunoassay interferences: Biotin taken in moderate to high doses can result in either false-high or -low values (19).

Dosage (OneMSK Only)
  1. Mason P. Dietary Supplements. London: Pharmaceutical Press; 2001.
  2. Keipert JA. Oral use of biotin in seborrhoeic dermatitis of infancy: a controlled trial. Med J Aust. 1976;1:584-5.
  3. Hochman LG, Scher RK, Meyerson MS. Brittle nails: response to daily biotin supplementation. Cutis 1993;51:303-5.
  4. Koutsikos D, Agroyannis B, Tzanatos-Exarchou H. Biotin for diabetic peripheral neuropathy. Biomed Pharmacother. 1990;44:511-4.
  5. Albarracin CA, Fuqua BC, Evans JL, et al. Chromium picolinate and biotin combination improves glucose metabolism in treated, uncontrolled overweight to obese patients with type 2 diabetes. Diabetes Metab Res Rev. Jan-Feb 2008;24(1):41-51.
  6. Debourdeau PM, et al. Life-threatening eosinophilic pleuropericardial effusion related to vitamins B5 and H. Ann Pharmacother. 2001;35:424-6.
  7. Braguer D, Gallice P, Yatzidis H, et al. Restoration by biotin of the in vitro microtubule formation inhibited by uremic toxins. Nephron. 1991;57(2):192-196.
  8. Desai S, Ganesan K, Hegde A. Biotinidase deficiency: a reversible metabolic encephalopathy. Neuroimaging and MR spectroscopic findings in a series of four patients. Pediatr Radiol. Aug 2008;38(8):848-856.
  9. Zempleni J, Helm RM, Mock DM. In vivo biotin supplementation at a pharmacologic dose decreases proliferation rates of human peripheral blood mononuclear cells and cytokine release. J Nutr. 2001;131:1479-84.
  10. Said HM, Redha R, Nylander W. Biotin transport in the human intestine: inhibition by anticonvulsant drugs. Am J Clin Nutr. 1989;49:127-31.
  11. Mock DM, et al. Disturbances in biotin metabolism in children undergoing long-term anticonvulsant therapy. J Pediatr Gastroenterol Nutr. 1998;26:245-50.
  12. Henry JG, Sobki S, Arafat N. Interference by biotin therapy on measurement of TSH and FT4 by enzyme immunoassay on Boehringer Mannheim ES700 analyser. Ann Clin Biochem. 1996;33 (Pt 2):162-3.
  13. Raha S, Udani V. Biotinidase deficiency presenting as recurrent myelopathy in a 7-year-old boy and a review of the literature. Pediatr Neurol. 2011 Oct;45(4):261-4.
  14. Singhi P, Ray M. Ohtahara syndrome with biotinidase deficiency. J Child Neurol. 2011 Apr;26(4):507-9.
  15. Komur M, Okuyaz C, Ezgu F, Atici A. A girl with spastic tetraparesis associated with biotinidase deficiency. Eur J Paediatr Neurol. 2011;5(6):551-3.
  16. Trueb RM. Serum Biotin Levels in Women Complaining of Hair Loss. Int J Trichology. Apr-Jun 2016;8(2):73-77.
  17. Tourbah A, Lebrun-Frenay C, Edan G, et al. MD1003 (high-dose biotin) for the treatment of progressive multiple sclerosis: A randomised, double-blind, placebo-controlled study. Mult Scler. Nov 2016;22(13):1719-1731.
  18. Ogawa Y, Kiba T, Nakano K, et al. [Prospective study of biotin treatment in patients with erythema due to gefitinib or erlotinib]. Gan To Kagaku Ryoho. Apr 2014;41(4):517-522.
  19. Elston MS, Sehgal S, Du Toit S, et al. Factitious Graves’ Disease Due to Biotin Immunoassay Interference-A Case and Review of the Literature. J Clin Endocrinol Metab. Sep 2016;101(9):3251-3255.
  20. Siddiqui U, Egnor E, Sloane JA. Biotin supplementation in MS clinically valuable but can alter multiple blood test results. Mult Scler. Apr 2017;23(4):619-620.
  21. Institute of Medicine Standing Committee on the Scientific Evaluation of Dietary Reference I, its Panel on Folate OBV, Choline. The National Academies Collection: Reports funded by National Institutes of Health. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington (DC): National Academies Press (US), National Academy of Sciences; 1998.
  22. U.S. Food and Drug Administration. The FDA Warns that Biotin May Interfere with Lab Tests: FDA Safety Communication. Statement issued November 28, 2017.
  23. Patel DP, Swink SM, Castelo-Soccio L. A Review of the Use of Biotin for Hair Loss. Skin Appendage Disord. Aug 2017;3(3):166-169. 
  24. Soleymani T, Lo Sicco K, Shapiro J. The Infatuation With Biotin Supplementation: Is There Truth Behind Its Rising Popularity? A Comparative Analysis of Clinical Efficacy versus Social Popularity. J Drugs Dermatol. May 1 2017;16(5):496-500. 
  25. Williams GR, Cervinski MA, Nerenz RD. Assessment of biotin interference with qualitative point-of-care hCG test devices. Clin Biochem. Mar 2018;53:168-170.
  26. Katzman BM, Lueke AJ, Donato LJ, et al. Prevalence of biotin supplement usage in outpatients and plasma biotin concentrations in patients presenting to the emergency department. Clin Biochem. Sep 2018;60:11-16.
  27. John JJ, Cooley V, Lipner SR. Assessment of biotin supplementation among patients in an outpatient dermatology clinic. J Am Acad Dermatol. Aug 2019;81(2):620-621.
  28. Frame IJ, Joshi PH, Mwangi C, et al. Susceptibility of Cardiac Troponin Assays to Biotin Interference. Am J Clin Pathol. Apr 2 2019;151(5):486-493.
  29. Mrosewski I, Neumann I, Switkowski R. Interference of High Dose Biotin Supplementation with Thyroid Parameters in Immunoassays Utilizing the Interaction between Streptavidin and Biotin: a Case Report and Review of Current Literature. Clin Lab. Jan 1 2019;65(1).
Back to top
Back to top
Email your questions and comments to

Last Updated