Vitamin B7 (Biotin) Research & Evidence

SupplementScience.ai Editorial Team·Evidence-Based Supplement Research

Published Mar 11, 2026

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

Evidence Level

Moderate

Biotin's evidence base is surprisingly thin for such a popular supplement. Patel et al. (2017) conducted a systematic review and found only 18 reported cases of biotin use for hair and nails, none from rigorous RCTs, concluding there is insufficient evidence for biotin supplementation in non-deficient individuals. Colombo et al. (1990) showed nail thickness improvement in patients with brittle nails, but the study lacked a control group. The most important clinical concern is the 2017 FDA safety communication warning that biotin can significantly interfere with laboratory tests, including troponin assays used to diagnose heart attacks — a potentially life-threatening issue if results are misinterpreted.

Evidence by Condition

Condition	Studied Dose	Evidence
General health	30-100 mcg daily	Strong
Brittle nails	2,500 mcg daily for 6+ months	Preliminary
Hair support	2,500-5,000 mcg daily (limited evidence)	Preliminary
Pregnancy	30-35 mcg daily as part of prenatal vitamin	Moderate

Full Vitamin B7 (Biotin) Guide

References

Patel DP, Swink SM, Castelo-Soccio L (2017). A review of the use of biotin for hair loss. Skin Appendage Disorders. DOI PubMed
FDA Safety Communication (2017). The FDA warns that biotin may interfere with lab tests. U.S. Food and Drug Administration.
Colombo 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