Biotin (Vitamin B7)

Last Updated: September 12, 2023

Biotin is one of the essential B vitamins used by the body primarily as an enzymatic cofactor. While it is popular as a beauty supplement for hair, skin, and nails and very preliminary evidence suggests it may have a role in these uses, its role is not well-supported. Potential interactions with diabetes are also not well understood.

Biotin (Vitamin B7) is most often used for

What is biotin?

Biotin is an essential vitamin that has been grouped with the B-complex vitamins since it was discovered in yeast alongside other B vitamins. Although it is technically known as vitamin B7, this designation is not too common as it is usually simply referred to as biotin. It was initially found to be a component of nails, skin, and hair to a relatively high degree.

What are biotin’s main benefits?

Biotin has been seen as the go-to vitamin for beauty ever since one pilot study in women with brittle nails showed supplementation to be beneficial. It is currently being marketed for improving nail, skin, and hair aesthetics. These claims, however, were not followed up scientifically so there is not much evidence to support biotin's role here. It can plausibly have these actions mechanistically, but there is simply not much evidence that can be used as support.

Overall, aside from instances where biotin may be deficient (alcoholism, some epileptic drug therapies, and overconsumption of raw egg whites) the supplement does not have any solid evidence for benefits and may have a role as a beauty supplement pending better evidence.

What are biotin’s main drawbacks?

Currently, while there is no evidence to suggest that biotin intake at levels well above the adequate intake levels of 5–35 mcg/day is toxic in humans, there are other risks to consider.[1][2] For one, excessive biotin intake can imitate some of the signs and symptoms of diabetes, such as excessive thirst and urination.[2] Further, biotin supplementation can cause inaccurate results on multiple categories of medical lab tests.
Case studies and comparative tests have shown that biotin may cause inaccurate lab results in, for example, immunoassays that use biotin-streptavidin technology. [3][4][5][6][7][8] Abnormally high or low readings as a result of biotin supplementation of as little as 10 mg/day could lead to misdiagnosis of pregnancy,[7] thyrotoxicosis,[8] Graves’ Disease,[9] and even heart attack.[6] Biotin concentrations are detectable in blood samples, which may help clinicians to assess whether biotin has affected a particular test result. Detectable levels of biotin have also resulted in false labs for serum tests including CK-MB, human chorionic gonadotropin (HCG, a hormone produced in pregnancy and some cancers), troponin, cortisol, ferritin, TSH, T3, T4, PTH, 25OHD, and prolactin; biotin may affect children’s and adults’ tests differently, and its effects on serum labs can also depend on intake levels.[5][6][7][8][10]

How does biotin work?

Biotin's general role as an enzymatic cofactor has also led to some research suggesting it may interact with glucose metabolism in the human body. As a general statement, it seems that in rodents with a higher circulating biotin level in their blood, the amount of insulin released in response to a glucose test is higher, leading to less elevation of glucose over time. This rodent evidence also reports that the higher glucose is not met with higher insulin resistance, suggesting a potentially beneficial role. Not too much evidence has been conducted in humans in regard to diabetes, with one study finding that intramuscular biotin was able to attenuate symptoms of neuropathy in three diabetic subjects.

What are other names for Biotin (Vitamin B7)?
Note that Biotin (Vitamin B7) is also known as:
  • Vitamin B7
  • Vitamin H
Dosage information

The only known supplemental dose of biotin that has been tested orally in humans — for the purposes of enhancing the quality of brittle nails — is 2.5mg taken once daily over six months.

This dose appears relatively safe, although it is much higher than the recommended daily intake (RDI) of biotin which ranges from 25-30mcg (youth) upwards to 100mcg (adults). The biotin dose found in many multivitamins (30mcg or 0.03mg) seems more than sufficient.

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Update History
2023-09-12 17:02:58

More safety information added


We added some more information on the potential effect of biotin on biomarkers such as thyroid hormone.

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  1. ^Institute of Medicine Food and Nutrition Board. Dietary Reference Intakes: Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline.National Academy Press.(1998)
  2. ^Bistas KG, Tadi P.Biotin StatPearls.(2023)
  3. ^Barbesino GMisdiagnosis of Graves' Disease with Apparent Severe Hyperthyroidism in a Patient Taking Biotin Megadoses.Thyroid.(2016-Jun)
  4. ^Piketty ML, Polak M, Flechtner I, Gonzales-Briceño L, Souberbielle JCFalse biochemical diagnosis of hyperthyroidism in streptavidin-biotin-based immunoassays: the problem of biotin intake and related interferences.Clin Chem Lab Med.(2017-May-01)
  5. ^Li D, Radulescu A, Shrestha RT, Root M, Karger AB, Killeen AA, Hodges JS, Fan SL, Ferguson A, Garg U, Sokoll LJ, Burmeister LAAssociation of Biotin Ingestion With Performance of Hormone and Nonhormone Assays in Healthy Adults.JAMA.(2017-Sep-26)
  6. ^Ali M, Rajapakshe D, Cao L, Devaraj SDiscordant Analytical Results Caused by Biotin Interference on Diagnostic Immunoassays in a Pediatric Hospital.Ann Clin Lab Sci.(2017-Sep)
  7. ^Goodrum JM, Nair VS, Moore C, Crouch AK, Eichner D, Miller GDImpact of Biotin Supplementation on Human Chorionic Gonadotropin Immunoassays Utilizing Biotin-Streptavidin Binding Methods in Urine.Clin Chem.(2023-Jul-05)
  8. ^James A, Stalan J, Kuzhively JBiotin induced biochemical hyperthyroidism: a case report and review of the literature.J Med Case Rep.(2023-Jun-28)
  9. ^Elston MS, Sehgal S, Du Toit S, Yarndley T, Conaglen JVFactitious Graves' Disease Due to Biotin Immunoassay Interference-A Case and Review of the Literature.J Clin Endocrinol Metab.(2016-Sep)
  10. ^Harley K, Bissonnette S, Inzitari R, Schulz K, Apple FS, Kavsak PA, Gunsolus ILIndependent and combined effects of biotin and hemolysis on high-sensitivity cardiac troponin assays.Clin Chem Lab Med.(2021-Jul-27)
  11. ^Depeint F, Bruce WR, Shangari N, Mehta R, O'Brien PJMitochondrial function and toxicity: role of the B vitamin family on mitochondrial energy metabolismChem Biol Interact.(2006 Oct 27)
  12. ^Selhub JFolate, vitamin B12 and vitamin B6 and one carbon metabolismJ Nutr Health Aging.(2002)
  13. ^Chen AC, Martin AJ, Choy B, Fernández-Peñas P, Dalziell RA, McKenzie CA, Scolyer RA, Dhillon HM, Vardy JL, Kricker A, St George G, Chinniah N, Halliday GM, Damian DLA Phase 3 Randomized Trial of Nicotinamide for Skin-Cancer ChemopreventionN Engl J Med.(2015 Oct 22)
  14. ^Brasky TM, White E, Chen CLLong-Term, Supplemental, One-Carbon Metabolism-Related Vitamin B Use in Relation to Lung Cancer Risk in the Vitamins and Lifestyle (VITAL) CohortJ Clin Oncol.(2017 Oct 20)
  15. ^White E, Patterson RE, Kristal AR, Thornquist M, King I, Shattuck AL, Evans I, Satia-Abouta J, Littman AJ, Potter JDVITamins And Lifestyle cohort study: study design and characteristics of supplement usersAm J Epidemiol.(2004 Jan 1)
  16. ^Kim YIFolate and colorectal cancer: an evidence-based critical reviewMol Nutr Food Res.(2007 Mar)
  17. ^Kok DE, Dhonukshe-Rutten RA, Lute C, Heil SG, Uitterlinden AG, van der Velde N, van Meurs JB, van Schoor NM, Hooiveld GJ, de Groot LC, Kampman E, Steegenga WTThe effects of long-term daily folic acid and vitamin B12 supplementation on genome-wide DNA methylation in elderly subjectsClin Epigenetics.(2015 Nov 14)
  18. ^Corbin JM, Ruiz-Echevarría MJOne-Carbon Metabolism in Prostate Cancer: The Role of Androgen SignalingInt J Mol Sci.(2016 Jul 27)
Examine Database References
  1. Blood glucose - Revilla-Monsalve C, Zendejas-Ruiz I, Islas-Andrade S, Báez-Saldaña A, Palomino-Garibay MA, Hernández-Quiróz PM, Fernandez-Mejia CBiotin supplementation reduces plasma triacylglycerol and VLDL in type 2 diabetic patients and in nondiabetic subjects with hypertriglyceridemiaBiomed Pharmacother.(2006 May)
  2. Multiple Sclerosis Symptoms - Bruce A C Cree, Gary Cutter, Jerry S Wolinsky, Mark S Freedman, Giancarlo Comi, Gavin Giovannoni, Hans-Peter Hartung, Douglas Arnold, Jens Kuhle, Valerie Block, Frederick E Munschauer, Frédéric Sedel, Fred D Lublin, SPI2 investigative teamsSafety and efficacy of MD1003 (high-dose biotin) in patients with progressive multiple sclerosis (SPI2): a randomised, double-blind, placebo-controlled, phase 3 trialLancet Neurol.(2020 Dec)
  3. Multiple Sclerosis Symptoms - Tourbah A, Lebrun-Frenay C, Edan G, Clanet M, Papeix C, Vukusic S, De Sèze J, Debouverie M, Gout O, Clavelou P, Defer G, Laplaud DA, Moreau T, Labauge P, Brochet B, Sedel F, Pelletier J, MD1003 (high-dose biotin) for the treatment of progressive multiple sclerosis: A randomised, double-blind, placebo-controlled study.Mult Scler.(2016-11)
  4. Multiple Sclerosis Symptoms - Sedel F, Papeix C, Bellanger A, Touitou V, Lebrun-Frenay C, Galanaud D, Gout O, Lyon-Caen O, Tourbah AHigh doses of biotin in chronic progressive multiple sclerosis: a pilot study.Mult Scler Relat Disord.(2015-Mar)
  5. Multiple Sclerosis Symptoms - Tourbah A, Gout O, Vighetto A, Deburghgraeve V, Pelletier J, Papeix C, Lebrun-Frenay C, Labauge P, Brassat D, Toosy A, Laplaud DA, Outteryck O, Moreau T, Debouverie M, Clavelou P, Heinzlef O, De Sèze J, Defer G, Sedel F, Arndt CMD1003 (High-Dose Pharmaceutical-Grade Biotin) for the Treatment of Chronic Visual Loss Related to Optic Neuritis in Multiple Sclerosis: A Randomized, Double-Blind, Placebo-Controlled Study.CNS Drugs.(2018-07)
  6. Triglycerides - Marshall MW, Kliman PG, Washington VA, Mackin JF, Weinland BTEffects of biotin on lipids and other constituents of plasma of healthy men and womenArtery.(1980)
  7. Nail Quality - Colombo VE, Gerber F, Bronhofer M, Floersheim GLTreatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopyJ Am Acad Dermatol.(1990 Dec)