General Dosage
2.5-5 mg (2,500-5,000 mcg) daily
Maximum dose: No established upper limit; doses up to 10 mg/day are used clinically without toxicity
Biotin Dosage Guide
Evidence:Moderate
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Dosage Recommendations
General recommendation: 2.5-5 mg (2,500-5,000 mcg) daily
Timing: Can be taken at any time of day
Dosage by Condition
Brittle nails
2.5 mg daily for 6+ monthsModerate
Hair thinning (with deficiency)
5 mg dailyModerate
General maintenance
30-100 mcg daily (adequate intake)Strong
Biotin deficiency
5-10 mg daily under medical supervisionStrong
| Condition | Recommended Dose | Evidence |
|---|---|---|
| Brittle nails | 2.5 mg daily for 6+ months | Moderate |
| Hair thinning (with deficiency) | 5 mg daily | Moderate |
| General maintenance | 30-100 mcg daily (adequate intake) | Strong |
| Biotin deficiency | 5-10 mg daily under medical supervision | Strong |
Upper limit: No established upper limit; doses up to 10 mg/day are used clinically without toxicity
Timing & Absorption
Can be taken at any time of day
Can be taken with or without food.
References
- ReviewPatel DP, Swink SM, Castelo-Soccio L. (2017). A review of the use of biotin for hair loss. Skin Appendage Disorders. DOI PubMed
- RCTColombo VE, Gerber F, Bronhofer M, Floersheim GL. (1990). Treatment of brittle fingernails and onychoschizia with biotin: scanning electron microscopy. Journal of the American Academy of Dermatology. DOI PubMed
- Lipner SR. (2018). Rethinking biotin therapy for hair, nail, and skin disorders. Journal of the American Academy of Dermatology. DOI PubMed
- U.S. Food and Drug Administration. (2017). The FDA warns that biotin may interfere with lab tests: FDA Safety Communication. FDA Safety Communication.
- Meta-analysisEspiritu AI, Remalante-Rayco PPM (2021). High-dose biotin for multiple sclerosis: A systematic review and meta-analyses of randomized controlled trials.. Multiple sclerosis and related disorders. DOI PubMed
- Chen B, Wang C, Wang YM, Liu JX (2011). Effect of biotin on milk performance of dairy cattle: a meta-analysis.. Journal of dairy science. DOI PubMed
- Lean IJ, Rabiee AR (2011). Effect of feeding biotin on milk production and hoof health in lactating dairy cows: a quantitative assessment.. Journal of dairy science. DOI PubMed
Show 5 more references
- Meta-analysisZhang Y, Ding Y, Fan Y, Xu Y, et al. (2022). Influence of biotin intervention on glycemic control and lipid profile in patients with type 2 diabetes mellitus: A systematic review and meta-analysis.. Frontiers in nutrition. DOI PubMed
- Elston MS, Sehgal S, Du Toit S, Yarndley T, et al. (2016). Factitious Graves' Disease Due to Biotin Immunoassay Interference-A Case and Review of the Literature.. The Journal of clinical endocrinology and metabolism. DOI PubMed
- Agrawal R (2026). Thyrotropin Controversy in Subclinical Thyroid Disorders.. The Journal of the Association of Physicians of India. DOI PubMed
- Hao Y, Sun D, Jiang X, Zhang A, et al. (2026). Integrated proteomics and metabolomics profiling reveal mechanisms for the improvement of hoof health, liver function, and oxidative stress in lactating dairy cows fed rumen-protected biotin.. Journal of dairy science. DOI PubMed
- Piquero-Casals J, Saceda-Corralo D, Aladren S, Bustos J, et al. (2025). Oral Supplementation with l-Cystine, Serenoa repens, Cucurbita pepo, and Pygeum africanum in Chronic Telogen Effluvium and Androgenetic Alopecia: A Double-Blind, Placebo-Controlled, Randomized Clinical Study.. Skin appendage disorders. DOI PubMed