5α-dihydro-11-keto Testosterone is an analytical reference standard that is structurally classified as a steroid hormone. It is a metabolite of 11β-hydroxyandrostenedione and 11β-hydroxytestosterone that has been shown to act as a full androgen receptor agonist with equal potency as that of dihydrotestosterone . The androgenic activity of 5α-dihydro-11-keto testosterone has been implicated in contributing to the androgen pool that drives castration-resistant prostate cancer cells. This product is intended for forensic and research applications.