Biotin
A B vitamin used in keratin production. Evidence that supplementing it improves hair growth in people who are not deficient is limited.
Common effects
- Biotin is generally well tolerated.
Serious effects
- Biotin interferes with laboratory immunoassays. It can make a troponin result (the test used to diagnose a heart attack) read falsely low, and it can distort thyroid results in both directions.
Tell your provider
- Tell any clinician and any lab that you take biotin before a blood test, and ask whether to stop it beforehand.
Sources
- The FDA warns that biotin may interfere with lab tests. US Food and Drug Administration. FDA safety communication
- Patel DP, Swink SM, Castelo-Soccio L. A review of the use of biotin for hair loss. Skin Appendage Disorders. Skin Appendage Disord 2017;3(3):166-169