spec sheet7 rows
17α-Allyl-19-nortestosterone A synthetic progestin and the major active metabolite of the oral progestogen allylestrenol. It is structurally related to both nandrolone and allyltestosterone but was never marketed as a standalone drug.
- Highly selective for the progesterone receptor with minimal androgenic activity
- Is the active metabolite of allylestrenol, a progestogen used clinically to help support pregnancy
Overview
Despite the steroid-family name it reads like an anabolic, this one is really a progesterone-receptor compound with almost no masculinizing activity; it's just how allylestrenol works once the body converts it.
Mechanism
It binds strongly to the progesterone receptor, with roughly 186% of progesterone's own binding affinity, while showing only weak affinity (about 4.5% that of testosterone) and negligible receptor binding. This gives it strong progestational activity with minimal androgenic (masculinizing) effect despite its steroid backbone.
receptor fingerprint
Progesterone receptorAgonist
Agonist
Safetyrisks and cautions, not medical advice
It has not been tested as a standalone drug in humans. As the active metabolite of allylestrenol, a progestogen used clinically to support pregnancy, its effects are presumed similar; allylestrenol has a long history of use with no reported teratogenic effects in animal studies.
Subjective profileweighing the evidence above
Nothing here to take or seek out. It exists as a metabolite, and whatever progestational effect it has is already delivered by allylestrenol, which was actually studied in people. Worth knowing for anyone tracing how a nandrolone-like backbone ends up almost purely progestogenic; that is the whole of its value.
Resources
This entry is here for reference.
Research
1 listed here; entry last updated July 2026
Reviews
My notesprivate to this device
FAQ
What is 17α-Allyl-19-nortestosterone used for?
It was never marketed on its own; its relevance is as the active form the body produces from allylestrenol, a progestogen used to support pregnancy.
How does 17α-Allyl-19-nortestosterone work?
It binds strongly to the progesterone receptor while binding only weakly to the androgen receptor, giving it progestin-like activity with little androgenic effect.
Is 17α-Allyl-19-nortestosterone well-researched?
Its receptor binding profile has been characterized in laboratory studies, but it has never been tested directly as an administered drug in humans.
Limitations of the evidence
- Never marketed or studied as a standalone drug in humans
Notes and cautions
- As a metabolite rather than an administered drug, its effects are inferred from allylestrenol rather than directly measured