Impact of Biotin Supplementation on Human Chorionic Gonadotropin Immunoassays Utilizing Biotin-Streptavidin Binding Methods in Urine.

This article investigates the impact of biotin supplementation on urinary human chorionic gonadotropin (hCG) immunoassays that utilize biotin-streptavidin binding methods, commonly employed in antidoping testing. In a controlled study with ten healthy males receiving hCG injections, those supplemented with 20 mg/day biotin showed a 500-fold increase in urinary biotin levels and a significant suppression of urinary hCG detection when tested with a biotin-dependent immunoassay, compared to a placebo group. This suppression was not observed in serum samples or when using a biotin-independent immunoassay, indicating that high urinary biotin interferes specifically with biotin-streptavidin based urine assays. The findings highlight a serious analytical problem for urine-based hCG testing in antidoping contexts and suggest that biotin-dependent immunoassays are not recommended for urine samples with elevated biotin levels.