Thiomesterone
Thiomesterone (tiomesterone) is an orally active anabolic-androgenic steroid, a 1,7-bis(acetylthio) derivative of methyltestosterone, marketed historically in Europe as Emdabol. It behaves as a 17-alpha-methylated oral androgen with the two acetylthio groups distinguishing it from the parent compound.
01 Overview
Thiomesterone was introduced in the 1960s as an oral anabolic agent and appeared in several European markets under the brand Emdabol. It is essentially methyltestosterone bearing acetylthio substitutions at the 1-alpha and 7-alpha positions, which modestly alter its pharmacology.
As a 17-alpha-alkylated oral steroid it carries the hepatic and endocrine liabilities typical of the class. It has been little studied in modern controlled trials, and most information derives from older pharmacological references and its historical clinical use for debilitated states.
02 Mechanism
Androgen-receptor agonist; a 17-alpha-methyl, 1,7-bis(acetylthio) methyltestosterone derivative with oral bioavailability.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Historical | 5–20 mg/day | Oral | Approximate range from older European formularies; poorly documented. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Anabolic / weight gainUsed historically to promote weight gain and recovery in debilitated patients. | unquantified | Anecdotal | |
| Androgenic supportAndrogen-receptor agonism inferred from methyltestosterone lineage. | unquantified | Preclinical |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| HPTA suppressionSuppression of endogenous testosterone. | Moderate | Expected | Preclinical | |
| HepatotoxicityCholestasis and transaminase elevation characteristic of 17-alkylated orals. | Severe | Class effect | Clinical |