DHT

What it measures, and what changes the number.

DHT (dihydrotestosterone) is a potent androgen formed from testosterone by the enzyme 5-alpha reductase, mainly in tissues such as skin, hair follicles and the prostate. The test measures the amount circulating in blood. Reports may list it as 'DIHYDROTESTOSTERONE, LC/MS/MS' or 'Dihidrotestosterona'.

It is typically read alongside total testosterone, SHBG and free testosterone, since DHT is made from testosterone and both bind to SHBG. Androstenedione may also be included.

The assay method matters: liquid chromatography with tandem mass spectrometry (LC/MS/MS) is more specific than older immunoassays, which can cross react with other steroids. Morning collection is common because testosterone varies through the day, and results are reported in either nmol/L or ng/dL.

Usually reported in nmol/L or ng/dL.

Often read alongside: Total testosterone, SHBG, Free testosterone (calculated), Androstenedione

Calculators that use it: DHT to estradiol ratio

Blood test glossary