Chlorodehydromethyltestosterone (Turinabol)
Chlorodehydromethyltestosterone ('Oral Turinabol', 'Tbol') is a 17α-methylated, 4-chloro derivative of methandienone. The chlorine at the 4 position blocks aromatisation, giving steady, oestrogen-free lean gains without water retention. It is infamous as the core agent of the East German state doping programme, and has an unusually long detection window from long-lived metabolites.
01 Overview
Developed by Jenapharm in the 1960s, Turinabol was administered systematically to East German athletes, making it one of the most notorious performance drugs in sporting history. Structurally it is methandienone with a 4-chloro substitution that removes aromatisation and androgenicity.
The result is a mild, controllable compound giving slow but clean lean-tissue and strength gains without bloat, often used as a milder oral or as an addition to other steroids. Its long-lived metabolites make it detectable in urine for many months, which repeatedly caught out re-tested Olympic samples years after competition.
02 Mechanism
Androgen-receptor agonist; the 4-chloro group prevents aromatisation and lowers androgenic potency, while 17α-methylation confers oral activity.
03 Dosing
| Tier | Dose | Route | Notes |
|---|---|---|---|
| Light | 10–20 mg/day | Oral | Mild entry range. |
| Common | 20–40 mg/day | Oral | Typical lean-gain range. |
| Heavy | 40–80 mg/day | Oral | Higher dosing raises hepatic and lipid strain. |
Ester comparison
| Ester | Half-life | Injection freq. | Testosterone by mass |
|---|
04 Effects
| Effect | Magnitude | Evidence | |
|---|---|---|---|
| Lean, dry gainsSteady lean-tissue and strength gains without water retention or bloat. | Observational | ||
| No oestrogenic effectsThe 4-chloro group prevents aromatisation, so no gynaecomastia or fluid gain. | Observational | ||
| Improved recovery and work capacityUsers report better training endurance and recovery. | Anecdotal |
05 Side effects
| Effect | Severity | Frequency | Evidence | Countermeasures |
|---|---|---|---|---|
| HepatotoxicityRaised liver enzymes with dose and duration, as with other 17α-alkylated orals. | Moderate | Common | Observational | |
| Adverse lipid changesReduces HDL and raises LDL like other non-aromatising orals. | Moderate | Common | Observational | |
| HPTA suppressionSuppresses endogenous testosterone, though somewhat milder than stronger orals at typical doses. | Moderate | Universal | Observational |