11-Ketotestosterone
An 11-oxygenated androgen (11-ketotestosterone / 11-oxo-testosterone) that is the principal androgen in fish and a natural minor human adrenal-pathway steroid. Marketed as a gray-market oral/prohormone; human anabolic data are minimal.
01 Overview
11-Ketotestosterone (11-oxo-testosterone) is a naturally occurring 11-oxygenated androgen, dominant in teleost fish and present in the human 11-oxyandrogen pathway. Interest in the 11-oxygenated androgens has grown in endocrinology, but that research concerns their physiology and role in conditions like PCOS and CAH, not their use as performance drugs.
As a supplement it has been sold as a mild androgen or prohormone. Direct human data on anabolic efficacy are minimal, and most rigorous literature addresses endogenous 11-oxyandrogen biology rather than exogenous dosing.
02 Mechanism
Androgen-receptor agonist; the 11-oxo group yields an androgen active at the AR without meaningful aromatisation to classical estrogens, part of the emerging 11-oxygenated androgen class.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Anecdotal | 25–75 mg/day | Oral | Supplement-label ranges; no clinical dosing. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Mild androgenic / anabolic effectMarketed for mild lean gains; no controlled human efficacy data. | unquantified | Anecdotal | |
| AR activation11-oxyandrogens activate the androgen receptor in assays. | moderate | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| HPTA suppressionExogenous androgen dosing can suppress endogenous testosterone. | Moderate | Expected | Anecdotal | |
| Androgenic skin effectsAcne / oily skin possible from androgen activity. | Mild | Occasional | Anecdotal |