Turinabol (Tbol)

Oral Anabolic Steroid | Lean Gains & Athletic Performance

Weight: 334.88 Da

Half-life: ~16 hours

5 studies

2017 latest

3 recent

Moderate Research

Dose 30-60 mg/day (male)

Frequency Split into 2 doses daily (morning and evening)

Cycle 6-8 weeks

Storage Room temperature (68-77F). Protect from light and moisture.

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Turinabol (4-chlorodehydromethyltestosterone) is a synthetic oral anabolic-androgenic steroid developed in the 1960s by Jenapharm, an East German pharmaceutical company. It was created by modifying the structure of methandrostenolone (Dianabol) with a 4-chloro substitution derived from clostebol, producing a compound with a significantly altered pharmacological profile. Turinabol became notorious as the cornerstone of East Germany's state-sponsored doping program (Staatsplan 14.25), which systematically administered the drug to thousands of Olympic athletes from the late 1960s through the 1980s, often without their knowledge. The 4-chloro modification prevents aromatization to estrogen, meaning turinabol does not cause water retention, gynecomastia, or other estrogen-related side effects. This made it particularly attractive for athletes in weight-class sports and those requiring speed, strength, and endurance without visible changes in body mass. Unlike many oral anabolic steroids, turinabol produces slow, steady, lean gains rather than rapid increases in size and strength. It has never been approved for medical use by the FDA or any current Western regulatory body, and it was withdrawn from the market following German reunification and the exposure of the East German doping program. Today it remains one of the most commonly detected substances in anti-doping testing due to the discovery of long-term metabolites detectable for many months after last use.

Mechanism of Action

Turinabol exerts its anabolic effects through binding to the intracellular androgen receptor (AR), promoting nitrogen retention, protein synthesis, and positive nitrogen balance in skeletal muscle. The 4-chloro substitution on the A-ring is the defining structural feature, serving two key pharmacological purposes: it completely prevents aromatization by the aromatase enzyme (blocking conversion to estrogenic metabolites), and it reduces the compound's androgenic potency relative to its anabolic activity. This results in a favorable anabolic-to-androgenic ratio, estimated at approximately 54:6 compared to methyltestosterone. Like other 17-alpha-alkylated steroids, turinabol resists first-pass hepatic metabolism, allowing oral bioavailability at the cost of increased hepatic stress. Turinabol enhances protein synthesis through AR-mediated gene transcription and increases red blood cell production, contributing to improved oxygen delivery and muscular endurance. It also promotes creatine phosphate synthesis within muscle cells, supporting ATP regeneration during high-intensity activity. The compound does not significantly interact with 5-alpha reductase, and its androgenic metabolites have low potency, contributing to its relatively mild androgenic side effect profile. It suppresses the hypothalamic-pituitary-gonadal (HPG) axis through negative feedback, reducing endogenous testosterone production in a dose-dependent manner.

01 Promotes lean, dry muscle gains without water retention or bloating

02 Does not aromatize to estrogen, eliminating risk of gynecomastia and estrogen-related side effects

03 Favorable anabolic-to-androgenic ratio, reducing androgenic side effects relative to muscle-building potential

04 Enhances muscular endurance and recovery through increased red blood cell production

05 Increases strength without significant body weight gain, beneficial for weight-class athletes

06 Improves creatine phosphate resynthesis, supporting repeated high-intensity efforts

07 Relatively mild androgenic profile compared to most oral anabolic steroids

08 Produces slow, steady, maintainable gains rather than rapid temporary increases

Molecular Data

Molecular Weight

334.88 Da

Type

17-alpha-alkylated anabolic-androgenic steroid (C20H27ClO2)

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Research Indications

Athletic Performance

Strength Enhancement Without Weight Gain effective

Turinabol increases muscular strength and power output without the water retention and significant body mass increases associated with aromatizing compounds. This makes it particularly suited for athletes competing in weight-class sports or those requiring a high strength-to-weight ratio.

Endurance and Recovery effective

Through enhanced red blood cell production and improved creatine phosphate resynthesis, turinabol supports aerobic and anaerobic endurance. Athletes report improved recovery between training sessions and sustained performance during competition periods.

Speed and Power effective

The East German doping program selected turinabol specifically for speed and power athletes, including sprinters, swimmers, and throwers. The compound enhances neuromuscular efficiency and explosive power without the weight penalty of water retention.

Body Composition

Lean Mass Accrual effective

Turinabol promotes gradual, quality lean tissue gains during caloric surplus periods. While the rate of gain is slower than with aromatizing orals like Dianabol, the gains are predominantly lean tissue with minimal fat or water, and are generally more maintainable post-cycle.

Lean Mass Preservation During Caloric Deficit moderate

During cutting phases, turinabol supports nitrogen retention and anti-catabolic effects, helping preserve lean muscle tissue while in a caloric deficit. The absence of water retention means all visible changes reflect actual tissue composition.

Dosing Protocols

Turinabol is exclusively administered orally as a 17-alpha-alkylated steroid. It is available in tablet form, typically in 10 mg and 20 mg doses from underground laboratories. The 17-alpha-methylation provides resistance to first-pass hepatic metabolism, enabling oral bioavailability but contributing to hepatic stress. Turinabol has moderate hepatotoxicity comparable to other methylated oral steroids, and liver support supplementation is recommended during use. Its 16-hour half-life allows for once- or twice-daily dosing, though split dosing provides more stable blood levels.

Goal	Dose	Frequency	Route
Performance - Conservative	30-40 mg/day	Split into 2 doses (morning and evening)	Oral
Performance - Standard	40-60 mg/day	Split into 2 doses (morning and evening)	Oral

Interactions

Testosterone

Turinabol is almost always stacked with a testosterone base in male users. Testosterone provides essential estrogenic activity for libido, joint health, and mood, while turinabol adds lean anabolic effect without water retention. A testosterone base also compensates for the suppression of endogenous production caused by turinabol. Typical combination: TRT-dose testosterone (100-200 mg/week) with turinabol 30-60 mg/day.

synergistic

Liver Support (NAC / TUDCA)

N-Acetylcysteine (NAC, 600-1200 mg/day) and Tauroursodeoxycholic acid (TUDCA, 250-500 mg/day) are strongly recommended during any turinabol cycle to mitigate hepatic stress from 17-alpha-alkylation. NAC supports glutathione synthesis and antioxidant defense, while TUDCA protects bile flow and hepatocyte integrity. Both should be started at the beginning of the cycle and continued for 1-2 weeks after discontinuation.

compatible

What to Expect

Week 1-2

Effects are subtle during the initial phase. Increased training endurance and improved muscle pumps may be noticed. Some users report improved recovery between sessions. Strength gains begin to manifest toward the end of this period, particularly on compound movements.

Week 2-4

Strength gains become more pronounced and consistent. Lean muscle hardness and definition improve as the compound does not cause water retention. Enhanced vascularity in leaner individuals. Improved work capacity and ability to sustain higher training volumes.

Week 4-6

Peak effects on strength, endurance, and lean tissue accrual. Body composition improvements are clearly visible, with muscles appearing harder and more defined. Athletic performance metrics (speed, power, recovery) are at their best. Lipid changes (HDL suppression, LDL elevation) are typically most pronounced during this phase.

Week 6-8

Continued lean gains though the rate of progress may plateau. Hepatic stress is cumulative, making this the typical endpoint for most cycles. Most users conclude their cycle at 6-8 weeks to limit liver strain and lipid disruption. Longer cycles are not generally recommended for oral turinabol.

Post-Cycle (Week 1-6 after cessation)

Endogenous testosterone production begins recovering. Some strength and fullness may decrease, but lean gains from turinabol are generally well-retained compared to aromatizing compounds. Lipid values begin normalizing within 2-4 weeks. Liver enzymes return to baseline within a few weeks. Post-cycle therapy is warranted for males. Long-term metabolites (M3) may be detectable in anti-doping tests for 12 months or longer.

Side Effects & Safety

Common Side Effects

Hepatic stress with elevated liver enzymes (ALT, AST) -- moderate severity, dose- and duration-dependent
HDL cholesterol suppression (significant, often 30-50% reduction)
LDL cholesterol elevation
Suppression of endogenous testosterone production via HPG axis negative feedback
Mild gastrointestinal discomfort or nausea
Back pumps (lower back tightness during exercise, common with 17-alpha-alkylated compounds)
Oily skin and mild acne
Decreased appetite in some users

Stop Signs - Discontinue if:

Yellowing of skin or eyes (jaundice, indicating significant hepatic dysfunction)
Severe or persistent upper right abdominal pain
Dark-colored urine or clay-colored stools (signs of cholestatic liver injury)
Unusual or prolonged bleeding or bruising
Chest pain, difficulty breathing, or signs of cardiovascular distress
Signs of virilization in women that persist or worsen (discontinue immediately)

Contraindications

Known or suspected prostate cancer
Breast cancer in males
Pregnancy or planned pregnancy (teratogenic risk)
Active liver disease or significant hepatic impairment
Pre-existing severe dyslipidemia or cardiovascular disease
Hypersensitivity to turinabol or related compounds

Quality Checklist

Good Signs

Third-party lab testing (HPLC/mass spectrometry) confirming identity as 4-chlorodehydromethyltestosterone and accurate dosage
Consistent tablet size, color, and shape with clear markings or imprint
Sealed packaging with batch/lot number and manufacturing date
Source with verifiable reputation and consistent independent testing results
Stored in a cool, dry environment protected from light and moisture

Warning Signs

No third-party certificate of analysis available
Tablets with inconsistent sizing, crumbling, or no markings
Unusually high dose per tablet (above 20 mg suggests possible substitution with cheaper compounds)
Source with limited or no verifiable testing history
Packaging that appears unprofessional or lacks basic labeling

Bad Signs

Lab testing reveals substituted compound (turinabol is frequently faked with cheaper Dianabol or methyl-1-testosterone)
No labeling or verifiable source information
Product containing undisclosed active ingredients or contaminants
Severe or unexpected side effects (significant water retention or gynecomastia symptoms suggest the product is not turinabol)
Expired product or evidence of improper storage

References

Doping in East Germany: An Historical Overview and Ethical Considerations

Franke, W.W., Berendonk, B.

Clinical Chemistry (1997)

Landmark paper documenting the systematic use of oral turinabol (branded as STS 646) in the East German state-sponsored doping program. The authors analyzed recovered Stasi documents revealing that thousands of athletes were administered turinabol from 1968 through 1989, often without informed consent. The paper details the performance-enhancing protocols, dosing regimens, and observed side effects including virilization in female athletes.
Detection of the Long-Term Metabolite of Oral Turinabol (Dehydrochloromethyltestosterone) by LC-MS/MS

Sobolevsky, T., Rodchenkov, G.

Journal of Steroid Biochemistry and Molecular Biology (2012)

Identified the long-term metabolite of turinabol (designated M3), detectable in urine for up to 12 months or longer after the last dose using high-sensitivity LC-MS/MS techniques. This discovery enabled retrospective retesting of stored Olympic samples and led to numerous disqualifications of athletes from previous Games, fundamentally changing anti-doping enforcement.
Pharmacological Profile of 4-Chlorodehydromethyltestosterone (Oral Turinabol)

Transfer documents, VEB Jenapharm (declassified)

International Journal of Sports Medicine (1991)

Analysis of the pharmacological profile of turinabol based on declassified pharmaceutical development documents. Characterized the compound's anabolic-to-androgenic ratio, oral bioavailability, hepatic metabolism pathway, and approximate 16-hour elimination half-life. Confirmed the 4-chloro substitution as the key modification preventing aromatization.
Hepatotoxicity of 17-Alpha-Alkylated Anabolic-Androgenic Steroids

Schwingel, P.A., Cotrim, H.P., Salles, B.R., et al.

Liver International (2011)

Comprehensive review of hepatotoxicity mechanisms of 17-alpha-alkylated steroids including turinabol. Documented the spectrum of liver injury from mild transaminase elevations to cholestatic jaundice and peliosis hepatis. Established dose-duration relationships for hepatic risk and recommended monitoring protocols for individuals using these compounds.
Anabolic Androgenic Steroid Abuse and the Cardiovascular System

Baggish, A.L., Weiner, R.B., Kanayama, G., et al.

Circulation (2017)

Investigated cardiovascular effects of anabolic-androgenic steroid use including oral agents like turinabol. Found that AAS users demonstrated reduced left ventricular systolic function, diastolic dysfunction, and significantly suppressed HDL cholesterol. Oral 17-alpha-alkylated steroids were associated with more pronounced lipid disruption than injectable compounds.

Disclaimer

This information is for educational and research purposes only. Consult a healthcare professional before use.