Androstanediol

Androstanediol or 3α-androstandiol (often abbreviated 3α-diol), also known as 5α-androstan-3α, 17β-diol, is an endogenous inhibiting androstane neurosteroid and a weak androgen , as well as the major metabolite of dihydrotestosterone (DHT). As a neurosteroid, it acts as a powerful positive allosteric modulator of the GABA receptor , and it has been found to have beneficial, anxiolytic , prosexual, and anticonvulsant effects. Since it is known that androgens, such as testosterone and DHT, have many of the same effects as 3α-diol, and are converted into it in vivo , it is believed that this compound may be partially responsible for these effects. Regarding its isomer 3β-androstanediol, which is a potent estrogen , 3α-androstanediol has a significantly lower, although still significant affinity for estrogen receptors , with a few times higher preference for ERβ compared to αα . It has approximately 0.07% and 0.3% affinity of estradiol for ERα and ERβ, respectively.

An orally active synthetic analogue of 3α-androstandiol, 17α-ethinyl-5α-androstan-3α, 17β-diol (HE-3235, Apoptone) was previously studied for the treatment of prostate cancer and breast cancer.