Trenbolone

a 19-nor trienic androgen used currently in cattle, with a French drug-archive record of historical human hexahydrobenzylcarbonate marketing but no modern controlled human therapeutic PK, outcome, or safety program.

tier F · androgens · 0 modern controlled human therapeutic trials

verdict

trenbolone is pharmacologically active and historically reached a human product, but the current evidence file fails the human PK, outcome, safety, and product-identity gates.

if you are asking whether trenbolone was literally never used as a human drug — a French drug archive records Parabolan, trenbolone hexahydrobenzylcarbonate 76 mg equivalent to 50 mg trenbolone base, as marketed from 1971 until 1997. this corrects the zero-human-contact claim, but it is not an official current-approval record.

if you are asking whether that makes current trenbolone evidence-based — no. no modern controlled therapeutic PK or safety trial was located, and acetate, enanthate, and hexahydrobenzylcarbonate are different formulations.

if you are asking what the 1.5-hour curve means — it is the measured disappearance half-life of free 17-beta-trenbolone after 10 mg radiolabeled trenbolone acetate was injected intravenously into two cows. it is animal-only and does not describe a human depot ester.

No half-life is borrowed for acetate implants, underground enanthate, or historical Parabolan. The displayed animal curve is explicitly free-parent cattle IV data.

why F-tier

F tier reflects failure of modern human PK, efficacy, safety, and current human-product thresholds. Historical French marketing corrects an absolute historical claim but does not repair the evidence file.

the core tension

Trenbolone has unusually strong animal pharmacology and a forgotten human product history, yet neither supplies the modern, formulation-specific human PK and safety evidence needed to cross the site's evidence gate.

what it is

Trenbolone is a 19-nor, delta-4,9,11 trienic androgen. Current US approvals are cattle ear implants containing trenbolone acetate. A French drug archive records historical Parabolan as the hexahydrobenzylcarbonate ester. Trenbolone enanthate sold in underground markets is a third formulation without an approved human product record.

what it does

After ester hydrolysis, free trenbolone activates the androgen receptor. In vitro binding work found 17-beta-trenbolone affinity similar to dihydrotestosterone at recombinant human androgen receptor and slightly higher than progesterone at bovine uterine progestin receptor; that bovine-receptor result does not quantify human clinical effects. In rats, trenbolone enanthate increased muscle and bone measures while suppressing testosterone and dihydrotestosterone and raising hemoglobin at higher exposures.

origin

Trenbolone acetate remains a veterinary growth-promoter implant in US cattle. A French drug archive records Parabolan human marketing from 1971 to 1997. The located human metabolism study exposed one person to radiolabeled free trenbolone but did not report plasma half-life.

why researchers are interested

The compound's reputation is built from animal anabolic activity and underground experience. Neither supplies controlled human cardiovascular, hematologic, reproductive, psychiatric, renal, or long-term safety estimates.

does it work

It changes body composition and androgen-sensitive endpoints in animals. That is preclinical efficacy, not a human outcome. F tier reflects the absence of a modern human safety and efficacy program and the product-identity problem, not a claim that the molecule is weak.

claims vs the data

• trenbolone was never used in humans anywhere — contradicted — a French drug archive records historical Parabolan marketing, and a primary one-person human tracer metabolism study exists.
• trenbolone has a proven human half-life — unsupported — no human plasma half-life for acetate, enanthate, hexahydrobenzylcarbonate, or free parent was located.
• the cattle implant curve applies to injections — contradicted — implant payout, intravenous free-parent disappearance, and intramuscular ester PK are different processes.

key facts

• molecular formula: C18H22O2 (free trenbolone); C20H24O3 (acetate)
• molecular weight: 270.37 g/mol (free); 312.41 g/mol (acetate)
• amino acids: n/a (steroidal small molecule, not a peptide)
• half-life: no measured human half-life; cattle free-parent disappearance about 1.5 hours after intravenous radiolabeled acetate
• type: 19-nor delta-4,9,11 trienic anabolic-androgenic steroid; current veterinary acetate and archive-recorded historical human hexahydrobenzylcarbonate are distinct esters
• CAS: 10161-33-8 (free); 10161-34-9 (acetate)
• 0 modern controlled human therapeutic trials
• 1.5 h cattle IV free-parent animal proxy
• 1997 historical Parabolan discontinued
• 3 ester identities that must not be merged

frequently asked questions

Was trenbolone ever marketed for humans?

Yes, historically. A French archive records Parabolan, trenbolone hexahydrobenzylcarbonate, as marketed from 1971 until discontinuation in 1997. It is not a current approval or a modern clinical evidence program.

Are acetate, enanthate, and Parabolan interchangeable?

No. They are different ester formulations. US veterinary products use acetate, the archive-recorded historical Parabolan product used hexahydrobenzylcarbonate, and underground enanthate has no located approved human dossier.

What is trenbolone's human half-life?

Unknown. The page shows a 1.5-hour cattle IV free-parent value only as an animal proxy and does not convert it into a human depot half-life.

Does animal muscle gain prove human efficacy?

No. Animal androgen effects establish biological activity, while human efficacy, organ risk, endocrine recovery, and safe exposure remain unmeasured in controlled modern trials.

related peptides

• Nandrolone — a 19-nor androgen with actual human ester PK
• Boldenone — another current veterinary-only anabolic with animal PK
• testosterone — the clinically characterized androgen comparator

reptides grades the research record and cites the literature behind every call. research reference only; not medical advice.