5a-dihydro-11-keto Testosterone-d3

5?-dihydro-11-keto Testosterone-d3 is intended for use as an internal standard for the quantification of 5?-dihydro-11-keto testosterone (Item No. 20200) by GC- or LC-MS. 5?-dihydro-11-keto Testosterone is a metabolite of 11?-hydroxyandrostenedione and 11?-hydroxytestosterone that has been shown to act as a full androgen receptor agonist with equal potency as that of dihydrotestosterone (Item No. 15874).{31737,31739,31738} The androgenic activity of 5?-dihydro-11-keto testosterone has been implicated in contributing to the androgen pool that drives castration-resistant prostate cancer cells.{31739,31738}