Note that although an active progestogen, retroprogesterone is not medically used.
The 19-norprogesterone derivatives gestonorone caproate (gestronol hexanoate), nomegestrol acetate, segesterone acetate (nestorone, elcometrine), and norgestomet are also derivatives of 17α-hydroxyprogesterone (see below).
Testosterone is instead classified as an anabolic-androgenic steroid and is included here purely because it is the parent structure of this group of progestins.
It is instead classified as an androgenic-anabolic steroid and is included here purely because it is an important parent structure of this group of progestins.
Note that although an active progestogen, SC-5233 (spirolactone) is not medically used.