Trenbolone — Potent 19-Nor Anabolic Steroid — Anabolic Steroids
Extremely potent veterinary anabolic steroid with no FDA-approved human formulation. High androgenic and anabolic activity with significant side effects.
Overview
Trenbolone is a 19-nor (19-nortestosterone) anabolic-androgenic steroid originally developed for veterinary use to increase muscle mass and feed efficiency in cattle (marketed as Finaplix-H implant pellets). It has never been approved for human use by any regulatory agency. Trenbolone has an anabolic:androgenic ratio of approximately 500:500 relative to testosterone (100:100), making it one of the most potent AAS in existence. It binds the androgen receptor with approximately 3-5 times greater affinity than testosterone and cannot be aromatized to estrogen due to the C19 modification. However, trenbolone is a potent progestin, binding the progesterone receptor with significant affinity, which can cause progesterone-related gynecomastia, prolactin elevation, and sexual dysfunction. Trenbolone is available in three ester forms: acetate (short-acting, daily injection), enanthate (long-acting, twice weekly), and hexahydrobenzylcarbonate (Parabolan, discontinued pharmaceutical grade). Notable side effects include severe insomnia, night sweats, cardiovascular strain, hepatotoxicity (with oral trenbolone), significant mood alterations (aggression, anxiety), and a characteristic cough upon injection ('tren cough') thought to result from prostaglandin-mediated bronchospasm. There is NO legitimate human clinical trial data for trenbolone.
Indications
- Veterinary use only: Cattle growth promotion (Finaplix-H pellets)
- No legitimate human medical indications
- Unapproved: Muscle hypertrophy and strength (bodybuilding use)
- Unapproved: Body recomposition
Mechanism of Action
Trenbolone binds the androgen receptor with 3-5x greater affinity than testosterone, producing powerful anabolic and androgenic signaling
Dosing
| Compound | Dose | Frequency | Notes |
|---|---|---|---|
| Trenbolone Acetate | 50-100 mg | Every other day | Common bodybuilding dose — NO clinical evidence; short ester |
| Trenbolone Enanthate | 200-400 mg | Once weekly | Long ester — bodybuilding dose range; NO clinical data |
Evidence Grade
GRADE D
Safety & Contraindications
- NO human safety data from clinical trials
- Severe cardiovascular risk: significant LDL increase and HDL suppression
- Night sweats and insomnia — very common and often severe
- Aggression, anxiety, and paranoia ('tren rage') reported frequently
- 'Tren cough' — immediate coughing fit post-injection due to prostaglandin release
- Severe HPG axis suppression — extended recovery may be needed
- Progesterone receptor agonism — gynecomastia, prolactin elevation
- Kidney stress — dark urine and elevated creatinine reported
- Hepatotoxicity with oral/methylated preparations
- Schedule III controlled substance in the United States