Formyldienolone
Formyldienolone (2-formyl-17-methyl-17-hydroxyestra-2,4-dien-3-one type designer steroid) is an obscure orally-active methylated 19-nor androgen appearing in grey-market prohormone products. It has essentially no clinical characterisation; it is treated as a progestational, non-aromatising 17-alpha-alkylated nandrolone-type oral with expected hepatotoxicity and strong suppression.
01 Overview
Formyldienolone belongs to the wave of 19-nor 'diene' designer steroids sold after older prohormones were scheduled. Its estra-diene backbone predicts nandrolone-like anabolic activity with progestogenic character rather than estrogenic aromatisation.
No human pharmacokinetic or safety studies exist. As a methylated 19-nor oral it is expected to be hepatotoxic and strongly suppressive, and progestogenic activity raises the risk of libido loss and, in susceptible users, nipple sensitivity despite lack of aromatisation.
02 Mechanism
Androgen-receptor agonist of the 19-nortestosterone class; 17-alpha-methyl group enables oral activity; diene ring system limits aromatisation while retaining progestogenic activity.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Anecdotal | 10–30 mg/day | Oral | Grey-market only; no medical basis. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Lean mass gainNandrolone-type anabolic activity claimed by users. | modest | Anecdotal | |
| Increased recoveryReported joint comfort/recovery typical of 19-nor compounds. | unclear | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Progestogenic side effectsLibido loss and possible nipple sensitivity from progestogenic activity. | Moderate | Common for 19-nor | Preclinical | |
| HepatotoxicityMethylated oral expected to elevate liver enzymes. | Severe | Expected for class | Preclinical | |
| HPTA suppressionStrong suppression typical of 19-nor androgens. | Severe | Universal | Preclinical |