Last Updated: September 28 2022

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 is most often used for


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. 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.

Beyond that, 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.

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 else is Biotin known as?
Note that Biotin 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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1.^Chapman-Smith A1, Cronan JE JrMolecular biology of biotin attachment to proteinsJ Nutr.(1999 Feb)
5.^Knowles JRThe mechanism of biotin-dependent enzymesAnnu Rev Biochem.(1989)
6.^Tong L1, Harwood HJ JrAcetyl-coenzyme A carboxylases: versatile targets for drug discoveryJ Cell Biochem.(2006 Dec 15)
7.^Huang CS1, Sadre-Bazzaz K, Shen Y, Deng B, Zhou ZH, Tong LCrystal structure of the alpha(6)beta(6) holoenzyme of propionyl-coenzyme A carboxylaseNature.(2010 Aug 19)
9.^Depeint F1, 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)
10.^Hymes J1, Wolf BHuman biotinidase isn't just for recycling biotinJ Nutr.(1999 Feb)
11.^Pispa JAnimal biotinidaseAnn Med Exp Biol Fenn.(1965)
14.^Kuroishi T1, Rios-Avila L, Pestinger V, Wijeratne SS, Zempleni JBiotinylation is a natural, albeit rare, modification of human histonesMol Genet Metab.(2011 Dec)
16.^Healy S1, Heightman TD, Hohmann L, Schriemer D, Gravel RANonenzymatic biotinylation of histone H2AProtein Sci.(2009 Feb)
17.^Eng WK1, Giraud D, Schlegel VL, Wang D, Lee BH, Zempleni JIdentification and assessment of markers of biotin status in healthy adultsBr J Nutr.(2013 Jul 28)
23.^Cowan TM1, Blitzer MG, Wolf B; Working Group of the American College of Medical Genetics Laboratory Quality Assurance CommitteeTechnical standards and guidelines for the diagnosis of biotinidase deficiencyGenet Med.(2010 Jul)
25.^Kresge N, Simoni RD, Hill RLThe Discovery of Avidin by Esmond E. SnellJ Biol Chem.(2004 Oct)
30.^White HB 3rd, Dennison BA, Della Fera MA, Whitney CJ, McGuire JC, Meslar HW, Sammelwitz PHBiotin-binding protein from chicken egg yolk. Assay and relationship to egg-white avidinBiochem J.(1976 Aug 1)
31.^Vesely DL, Kemp SF, Elders MJIsolation of a biotin receptor from hepatic plasma membranesBiochem Biophys Res Commun.(1987 Mar 30)
33.^Wuerges J1, Geremia S, Randaccio LStructural study on ligand specificity of human vitamin B12 transportersBiochem J.(2007 May 1)
34.^Horn MA1, Heinstein PF, Low PSBiotin-mediated delivery of exogenous macromolecules into soybean cellsPlant Physiol.(1990 Aug)
35.^Russell-Jones G1, McTavish K, McEwan J, Rice J, Nowotnik DVitamin-mediated targeting as a potential mechanism to increase drug uptake by tumoursJ Inorg Biochem.(2004 Oct)
37.^Chauhan J, Dakshinamurti KRole of human serum biotinidase as biotin-binding proteinBiochem J.(1988 Nov 15)
39.^Said HM1, Redha RBiotin transport in rat intestinal brush-border membrane vesiclesBiochim Biophys Acta.(1988 Nov 22)
41.^Balamurugan K1, Ortiz A, Said HMBiotin uptake by human intestinal and liver epithelial cells: role of the SMVT systemAm J Physiol Gastrointest Liver Physiol.(2003 Jul)
42.^Prasad PD1, Wang H, Kekuda R, Fujita T, Fei YJ, Devoe LD, Leibach FH, Ganapathy VCloning and functional expression of a cDNA encoding a mammalian sodium-dependent vitamin transporter mediating the uptake of pantothenate, biotin, and lipoateJ Biol Chem.(1998 Mar 27)
43.^Subramanian VS1, Marchant JS, Boulware MJ, Ma TY, Said HMMembrane targeting and intracellular trafficking of the human sodium-dependent multivitamin transporter in polarized epithelial cellsAm J Physiol Cell Physiol.(2009 Apr)
44.^Subramanya SB1, Subramanian VS, Kumar JS, Hoiness R, Said HMInhibition of intestinal biotin absorption by chronic alcohol feeding: cellular and molecular mechanismsAm J Physiol Gastrointest Liver Physiol.(2011 Mar)
46.^Wang H1, Huang W, Fei YJ, Xia H, Yang-Feng TL, Leibach FH, Devoe LD, Ganapathy V, Prasad PDHuman placental Na+-dependent multivitamin transporter. Cloning, functional expression, gene structure, and chromosomal localizationJ Biol Chem.(1999 May 21)
47.^Said HM1, Horne DW, Mock DMEffect of aging on intestinal biotin transport in the ratExp Gerontol.(1990)
49.^León-Del-Río A1, Hol-Soto-Borja D, Velázquez AStudies on the mechanism of biotin uptake by brush-border membrane vesicles of hamster enterocytesArch Med Res.(1993 Summer)
51.^Grafe F1, Wohlrab W, Neubert RH, Brandsch MTransport of biotin in human keratinocytesJ Invest Dermatol.(2003 Mar)
52.^Makino Y1, Osada K, Sone H, Sugiyama K, Komai M, Ito M, Tsunoda K, Furukawa YPercutaneous absorption of biotin in healthy subjects and in atopic dermatitis patientsJ Nutr Sci Vitaminol (Tokyo).(1999 Jun)
53.^Gilby ED, Taylor KJUltrasound monitoring of hepatic metastases during chemotherapyBr Med J.(1975 Feb 15)
57.^Bogusiewicz A1, Stratton SL, Ellison DA, Mock DMBiotin accounts for less than half of all biotin and biotin metabolites in the cerebrospinal fluid of childrenAm J Clin Nutr.(2008 Nov)
58.^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)
59.^Beinlich CJ1, Naumovitz RD, Song WO, Neely JRMyocardial metabolism of pantothenic acid in chronically diabetic ratsJ Mol Cell Cardiol.(1990 Mar)
60.^Baur B1, Wick H, Baumgartner ERNa(+)-dependent biotin transport into brush-border membrane vesicles from rat kidneyAm J Physiol.(1990 Apr)
62.^Said HM1, Korchid S, Horne DW, Howard MTransport of biotin in basolateral membrane vesicles of rat liverAm J Physiol.(1990 Nov)
64.^Prasad PD1, Wang H, Huang W, Fei YJ, Leibach FH, Devoe LD, Ganapathy VMolecular and functional characterization of the intestinal Na+-dependent multivitamin transporterArch Biochem Biophys.(1999 Jun 1)
65.^Krause KH, Bonjour JP, Berlit P, Kochen WBiotin status of epilepticsAnn N Y Acad Sci.(1985)
66.^Castro-Gago M1, Gómez-Lado C, Eirís-Puñal J, Díaz-Mayo I, Castiñeiras-Ramos DESerum biotinidase activity in children treated with valproic acid and carbamazepineJ Child Neurol.(2010 Jan)
67.^Castro-Gago M1, Pérez-Gay L, Gómez-Lado C, Castiñeiras-Ramos DE, Otero-Martínez S, Rodríguez-Segade SThe influence of valproic acid and carbamazepine treatment on serum biotin and zinc levels and on biotinidase activityJ Child Neurol.(2011 Dec)
70.^Larrieta E1, Velasco F, Vital P, López-Aceves T, Lazo-de-la-Vega-Monroy ML, Rojas A, Fernandez-Mejia CPharmacological concentrations of biotin reduce serum triglycerides and the expression of lipogenic genesEur J Pharmacol.(2010 Oct 10)
72.^Ha J1, Daniel S, Broyles SS, Kim KHCritical phosphorylation sites for acetyl-CoA carboxylase activityJ Biol Chem.(1994 Sep 2)
74.^Revilla-Monsalve C1, 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)
75.^Sarabu R1, Grimsby JTargeting glucokinase activation for the treatment of type 2 diabetes--a status reviewCurr Opin Drug Discov Devel.(2005 Sep)
76.^Dakshinamurti K, Cheah-Tan CLiver glucokinase of the biotin deficient ratCan J Biochem.(1968 Jan)
77.^Dakshinamurti K, Tarrago-Litvak L, Hong HCBiotin and glucose metabolismCan J Biochem.(1970 Apr)
82.^Chauhan J1, Dakshinamurti KTranscriptional regulation of the glucokinase gene by biotin in starved ratsJ Biol Chem.(1991 Jun 5)
83.^Dakshinamurti K, Cheah-Tan CBiotin-mediated synthesis of hepatic glucokinase in the ratArch Biochem Biophys.(1968 Sep 20)
85.^De La Vega LA1, Stockert RJRegulation of the insulin and asialoglycoprotein receptors via cGMP-dependent protein kinaseAm J Physiol Cell Physiol.(2000 Dec)
86.^Lazo de la Vega-Monroy ML1, Larrieta E, German MS, Baez-Saldana A, Fernandez-Mejia CEffects of biotin supplementation in the diet on insulin secretion, islet gene expression, glucose homeostasis and beta-cell proportionJ Nutr Biochem.(2013 Jan)
87.^Sasaki Y, Sone H, Kamiyama S, Shimizu M, Shirakawa H, Kagawa Y, Komai M, Furukawa YAdministration of biotin prevents the development of insulin resistance in the skeletal muscles of Otsuka Long-Evans Tokushima Fatty ratsFood Funct.(2012 Apr)
88.^Koutsikos D1, Agroyannis B, Tzanatos-Exarchou HBiotin for diabetic peripheral neuropathyBiomed Pharmacother.(1990)
89.^Krause KH, Berlit P, Bonjour JPImpaired biotin status in anticonvulsant therapyAnn Neurol.(1982 Nov)
91.^THOMPSON RH, BUTTERFIELD WJ, FRY IKPyruvate metabolism in diabetic neuropathyProc R Soc Med.(1960 Feb)
93.^Xu C1, Bai B, Fan P, Cai Y, Huang B, Law IK, Liu L, Xu A, Tung C, Li X, Siu FM, Che CM, Vanhoutte PM, Wang YSelective overexpression of human SIRT1 in adipose tissue enhances energy homeostasis and prevents the deterioration of insulin sensitivity with ageing in miceAm J Transl Res.(2013 May 24)
95.^Mao J1, Yang T, Gu Z, Heird WC, Finegold MJ, Lee B, Wakil SJaP2-Cre-mediated inactivation of acetyl-CoA carboxylase 1 causes growth retardation and reduced lipid accumulation in adipose tissuesProc Natl Acad Sci U S A.(2009 Oct 13)
96.^Fukuwatari T1, Wada H, Shibata KAge-related alterations of B-group vitamin contents in urine, blood and liver from ratsJ Nutr Sci Vitaminol (Tokyo).(2008 Oct)
97.^Mock DM1Skin manifestations of biotin deficiencySemin Dermatol.(1991 Dec)
98.^Gschwandtner M1, Mildner M, Mlitz V, Gruber F, Eckhart L, Werfel T, Gutzmer R, Elias PM, Tschachler EHistamine suppresses epidermal keratinocyte differentiation and impairs skin barrier function in a human skin modelAllergy.(2013 Jan)
99.^Ogawa Y1, Kiba T, Nakano K, Fujiwara K, Taniguchi H, Hosokawa A, Nakashima T, Kimoto S, Kajiume S, Okada Y, Ichiba YProspective study of biotin treatment in patients with erythema due to gefitinib or erlotinibGan To Kagaku Ryoho.(2014 Apr)
100.^Zempleni J1, Hassan YI, Wijeratne SSBiotin and biotinidase deficiencyExpert Rev Endocrinol Metab.(2008 Nov 1)
101.^Korkmazer N1, Vurucu S, Demirkaya E, Unay B, Kul M, Akin R, Gokcay ESerum and liver tissue biotinidase enzyme activity in rats which were administrated to valproic acidBrain Dev.(2006 Sep)
103.^Schulpis KH1, Karikas GA, Tjamouranis J, Regoutas S, Tsakiris SLow serum biotinidase activity in children with valproic acid monotherapyEpilepsia.(2001 Oct)
104.^Luís PB1, Ruiter JP, IJlst L, Diogo L, Garcia P, de Almeida IT, Duran M, Wanders RJ, Silva MFInhibition of 3-methylcrotonyl-CoA carboxylase explains the increased excretion of 3-hydroxyisovaleric acid in valproate-treated patientsJ Inherit Metab Dis.(2012 May)
106.^CUNHA TJ, LINDLEY DC, ENSMINGER MEBiotin deficiency syndrome in pigs fed desicated egg whiteJ Anim Sci.(1946 May)
107.^Colombo VE, Gerber F, Bronhofer M, Floersheim GLTreatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopyJ Am Acad Dermatol.(1990 Dec)
108.^Colombo VE1, Gerber F, Bronhofer M, Floersheim GLTreatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopyJ Am Acad Dermatol.(1990 Dec)
112.^Said HM1, Sharifian A, Bagherzadeh A, Mock DChronic ethanol feeding and acute ethanol exposure in vitro: effect on intestinal transport of biotinAm J Clin Nutr.(1990 Dec)