Methylclostebol
A 4-chloro, 17alpha-methylated designer steroid marketed briefly in gray-market products, combining the chlorinated backbone of clostebol with oral C17 alkylation. Essentially no human research; considered non-aromatising and orally hepatotoxic.
01 Overview
Methylclostebol (4-chloro-17alpha-methyltestosterone) is a methylated version of clostebol, appearing in unregulated 'prohormone' products marketed to bodybuilders. The 4-chloro substitution blocks aromatisation and 5alpha-reduction while the C17 methyl group makes it orally active.
There is no published clinical pharmacology. Assessments rely entirely on structural analogy to clostebol and oxymetholone-class orals plus scattered user reports.
02 Mechanism
Androgen-receptor agonist; 4-chloro substitution prevents aromatisation and 5alpha-reduction, while C17 methylation confers oral bioavailability.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Anecdotal | 10–30 mg/day | Oral | Gray-market label ranges only. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Non-estrogenic mass gainReported lean gains without aromatisation, by analogy to clostebol. | unquantified | Anecdotal | |
| Oral anabolic activityStructure predicts orally active androgen activity. | unquantified | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| Hepatotoxicity17alpha-alkylation causes liver strain. | Moderate | Class-typical | Preclinical | |
| HPTA suppressionSuppression of endogenous testosterone from exogenous androgen. | Moderate | Expected | Anecdotal |