Invalidation of a commercially available human 5α-dihydrotestosterone immunoassay

- We evaluated the validity of a commercial dihydrotestosterone (DHT) immunoassay.
- Immunoassay overestimated DHT concentrations by 79-1000% compared with LC-MS/MS.
- Immunoassay did not detect reductions in DHT following finasteride treatment.
- Cross-reactivity of the DHT immunoassay ranged from 18% to 99% with testosterone (T).
- This immunoassay is invalid for DHT assessment in biological fluids containing T.