Trenbolone Hexahydrobenzylcarbonate (Parabolan) - Long-Acting Trenbolone — Anabolic Steroids

The original pharmaceutical-grade trenbolone manufactured by Negma Laboratories (France), a long-acting ester with a 14-day half-life historically used for muscle wasting and cachexia.

Overview

Trenbolone hexahydrobenzylcarbonate (brand name Parabolan) was the only pharmaceutical-grade trenbolone product ever manufactured for human use, produced by Negma Laboratories in France from 1980 until discontinuation in 1997. Trenbolone is a 19-nortestosterone derivative with approximately 5x the anabolic and androgenic potency of testosterone. The hexahydrobenzylcarbonate ester provides a prolonged half-life of approximately 14 days, allowing less frequent injection schedules compared to trenbolone acetate. Originally indicated for muscle wasting, cachexia, malnutrition, and osteoporosis. Trenbolone does not aromatize to estrogen but is a potent progestational agent, which can cause prolactin-related side effects including gynecomastia via progesterone receptor activation. It is among the most potent anabolic steroids known, with profound effects on nutrient partitioning, nitrogen retention, and IGF-1 expression, but carries significant cardiovascular, neuropsychiatric, and renal risks. All current trenbolone preparations are underground laboratory products. PMID: 2892903, 24687017, 21266670.

Indications

  • Historical: muscle wasting, malnutrition, and cachexia (Negma Laboratories, France 1980-1997)
  • Historical: osteoporosis treatment in both sexes (European indication)
  • Bodybuilding: pre-contest cutting and recomposition (off-label, non-medical)
  • Bodybuilding: lean mass accrual without water retention (off-label, non-medical)

Mechanism of Action

Trenbolone binds the androgen receptor with approximately 5x the affinity of testosterone, driving maximal transcriptional activation of anabolic genes in muscle tissue

Dosing

CompoundDoseFrequencyNotes
Trenbolone Hexahydrobenzylcarbonate152 mgEvery 10-14 daysOriginal Negma pharmaceutical dosing (76mg/mL, 1.5mL ampule); equivalent to ~100mg trenbolone base
Trenbolone Hexahydrobenzylcarbonate228 mgEvery 10-14 daysHigher pharmaceutical dose for severe wasting; 2 ampules
Trenbolone Hexahydrobenzylcarbonate200 mgWeeklyBodybuilding dose; significantly exceeds pharmaceutical protocols
Trenbolone Hexahydrobenzylcarbonate400 mgWeeklyAdvanced bodybuilding dose; very high side effect burden

Evidence Grade

GRADE D

Safety & Contraindications

  • No current pharmaceutical production; all products are underground laboratory manufactured with inherent quality control risks
  • Severe cardiovascular risk: significant HDL suppression, left ventricular hypertrophy, and accelerated atherosclerosis with chronic use
  • Neuropsychiatric effects: insomnia, night sweats (trenbolone sweats), anxiety, aggression, and paranoia are commonly reported
  • Progestational activity: can cause prolactin elevation leading to galactorrhea, sexual dysfunction, and gynecomastia despite lack of aromatization
  • Nephrotoxicity: trenbolone metabolites excreted renally; dark-colored urine (oxidized trenbolone) is common; monitor kidney function
  • Profoundly suppressive to HPTA: recovery may be prolonged (months); robust PCT essential