Turinabol (4-Chlorodehydromethyltestosterone)
TBol · T-Bol · Chlorodehydromethyltestosterone
4-Chlorodehydromethyltestosterone, commonly known as Turinabol or Oral Turinabol (OT), is an orally active anabolic-androgenic steroid, structurally a chlorinated derivative of methandrostenolone (Dianabol) with a 4-chloro substitution and a 1,2-double bond. It is C17-alpha-alkylated for oral bioavailability. Developed by Jenapharm in East Germany in 1961 and clinically approved there through 1994, it became infamous as the core compound in the East German state-sponsored doping program (Stasi-documented administration to Olympic athletes from the 1960s through the 1980s).
Split daily dose into AM and PM given the ~16 hour half-life. Always pair with a testosterone base. Plan liver enzyme monitoring (ALT/AST, GGT) pre, mid-cycle, and post. Be aware of the very long detection window (6-12+ months) if competing in tested sport.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
How it works
Turinabol binds the androgen receptor (AR) with moderate affinity and drives protein synthesis and nitrogen retention. The 4-chloro substitution blocks aromatase activity, so it does not convert to estrogen - eliminating estrogenic side effects like water retention and gynecomastia.
It has relatively low androgenic effect for an oral AAS - androgenic sides (skin, hair) are milder than other 17-aa orals. It also has modest SHBG-binding activity, slightly raising free testosterone from a co-administered testosterone base.
The C17-alpha-alkyl group protects the molecule from first-pass hepatic metabolism, giving high oral bioavailability but imparting hepatotoxicity typical of the oral steroid class. Endogenous testosterone is suppressed via HPT-axis feedback; a testosterone base is standard in men. Lipid profile shift (HDL drop, LDL rise) occurs but is generally milder than with Dianabol or Winstrol.
An important anti-doping note: turinabol metabolites (particularly 4-chloro-18-nor-17beta-hydroxymethyl-17alpha-methyl-5beta-androst-13-en-3alpha-ol) persist in urine for 6-12 months or longer after use, making it easily detectable in drug-tested sport.
What to expect
First 1-2 weeks: mild strength improvements. No dramatic scale weight change - expect slow and steady rather than rapid gains.
Weeks 3-5: visible lean mass gains, improved pump, sharper appearance. Liver enzymes should be checked mid-cycle.
Weeks 6-8: peak benefits. Continued use beyond 8 weeks offers diminishing returns and escalating hepatic / lipid risk. Plan cycle-off at least equal to the on period.
Evidence
References for this compound are being re-checked against their source records. We are not showing them until each one is confirmed to support the claim it sits under.
Side effects & safety
Commonly reported
- Elevated liver enzymes (ALT/AST) - typically 2-3x ULN during use
- Suppression of endogenous testosterone (dose-dependent)
- Lipid shift (HDL drop, LDL rise) - milder than Dianabol
- Mild acne or oily skin
Less common & notes
- Headache, insomnia, mood changes, accelerated hair loss in genetically predisposed users, elevated blood pressure.
- Women: virilization signs (voice deepening, clitoral enlargement, facial hair) at doses above 10mg/day - stop immediately if these appear.
- Rare but serious: cholestatic jaundice, hepatic adenoma with prolonged or supratherapeutic use.
Pharmacokinetics
Metabolites detectable 6-12+ months in urine
Oral
Per dose - supports 1-2x daily dosing
Hepatic (CYP3A4). Renal excretion of metabolites.
Storage. Store at controlled room temperature (20-25°C / 68-77°F). Protect from moisture and light. Keep in original container with desiccant when available. Keep out of reach of children and in a locked location - Schedule III controlled substance in the United States.
Regulatory status
Schedule III controlled substance in the United States under the Anabolic Steroids Control Act of 1990. Never FDA-approved. Originally marketed as Oral-Turinabol by Jenapharm in East Germany (approval withdrawn 1994 following reunification). No current legitimate pharmaceutical source. Possession or distribution without a valid prescription is a federal offense in the United States.
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