The full, current guide is our Trenavar research guide.
Trenavar is sold by SARMs Store strictly as a research compound. Nothing on this page is medical advice or an instruction for human use.
Trenavar is one of the more heavily discussed compounds in the prohormone category and one of the least studied. Almost everything written about it is inference: from its chemistry, from the veterinary literature on the compound it converts to, and from anecdote. This page separates the parts that rest on published work from the parts that do not, because with Trenavar that distinction covers most of the subject.
What Trenavar is
Trenavar is the market name for trendione, chemically estra-4,9,11-triene-3,17-dione. It appeared on the supplement market around 2011 and 2012, part of the wave of products sold in the United States under the prohormone label.
Its structure is the same triene-containing estrane skeleton as trenbolone, differing at the 17 position: trendione carries a ketone where trenbolone carries a hydroxyl group. That single difference is the whole design. The enzyme 17-beta-hydroxysteroid dehydrogenase, widely distributed in human tissue including liver and muscle, reduces 17-ketones to 17-hydroxyls as part of normal hormone metabolism. Trendione is therefore expected to convert in the body to trenbolone, and it is a genuine prohormone in the strict sense: a less active precursor of an active androgen.
Notably, trendione is not 17-alpha-alkylated. It lacks the methyl group at carbon 17 responsible for the cholestatic liver injury pattern seen with Epistane, methasterone and methylstenbolone. That is a real structural difference and it is often cited in its favour. It does not mean the compound is free of hepatic risk, since liver injury case reports exist for non-alkylated compounds too.
What the research found
There are no human trials of trendione. No efficacy study, no safety study, no pharmacokinetic study establishing what proportion converts to trenbolone in people or how quickly. Any figure quoted for conversion efficiency is not from a published human study.
What exists is the literature on the product of that conversion.
Receptor affinity. Bauer and colleagues, in APMIS in 2000, characterised the binding affinity of a range of anabolic agents to the human androgen receptor, human sex hormone binding globulin and the bovine progestin receptor. Trenbolone binds the androgen receptor with high affinity, similar to dihydrotestosterone, and also binds the bovine progestin receptor slightly more strongly than progesterone itself. That combination underlies both its potency and its distinctive side effect discussion. Trendione, by contrast, bound the androgen receptor at less than 5 per cent of the affinity of trenbolone, which fits its role as a precursor rather than an active hormone.
In vivo activity. Wilson and colleagues, in Toxicological Sciences in 2002, demonstrated the potent androgenic and anabolic activity of 17-beta-trenbolone in the standard rodent Hershberger assay, confirming that the receptor affinity translates into tissue-level effect.
Veterinary use. Trenbolone acetate has been used for decades as a growth promoting implant in beef cattle, generating a substantial body of work on nitrogen retention, feed conversion, carcass composition and residue kinetics. It is genuine science and it is genuinely about cattle. Growth promotion in ruminants on controlled rations is not a model for human body composition.
Metabolism work. In cattle given trenbolone acetate, trendione is one of the metabolites found in excreta, which shows the 17 position is readily changed in the body (Robinson and colleagues, Environmental Toxicology and Chemistry, 2017). Anti-doping laboratories detect trenbolone and its urinary metabolites (de Boer and colleagues, 1991). We have not found a peer-reviewed human study that measures how much trendione is converted to trenbolone.
Side effects reported
Everything in this section is inferred from trenbolone rather than measured for trendione, and should be read that way.
The effects attributed to trenbolone in the veterinary and receptor literature, and to androgens generally in the clinical literature, include marked suppression of endogenous testosterone and luteinising hormone, substantial adverse changes to the lipid profile with HDL cholesterol falling sharply, raised blood pressure, and the effects associated with progesterone receptor activity. Trenbolone is not aromatised to oestradiol, which changes the character of the oestrogenic side effect discussion without eliminating it, because progestogenic activity can produce overlapping effects.
The honest summary is that the side effect profile of Trenavar in humans has never been characterised in a controlled setting. The absence of 17-alpha-alkylation removes one specific and well-documented risk. It does not create a safety record.
Comparison with related compounds
Set against SARMs, the contrast is instructive. Ostarine has phase III human data, with modest lean mass changes and reversible hormonal changes reported in the trials. Trendione has no human data at all, but is expected to convert to a compound whose androgen receptor affinity is similar to dihydrotestosterone. Greater potency at the receptor is not the same as a better risk-to-benefit ratio, particularly when the benefit side has never been measured. Trendione differs from Epistane and methylstenbolone in not being methylated, and from most prohormones in converting to a non-aromatising, progestogenic androgen rather than to testosterone.
How to check a supplier
Verification matters more, not less, for a compound with no clinical record. Ask for the batch-specific certificate of analysis from an independent laboratory, confirming identity by HPLC or LC-MS, stating a purity figure, and carrying a batch number matching the bottle. The label should declare the chemical name as well as the market name, the amount per capsule, the capsule count and a research-only notice. Alpha Labs Trenavar is made in the UK at 20 mg per capsule, 90 capsules per bottle, and batch certificates of analysis are being published on the product page as testing is completed.
Frequently asked questions
What does Trenavar convert to? Trendione carries a 17-ketone that 17-beta-hydroxysteroid dehydrogenase reduces to a 17-hydroxyl, yielding trenbolone. That conversion is expected from its chemistry; we have not found a peer-reviewed human study measuring it.
Are there human studies of Trenavar? No. There are no efficacy, safety or pharmacokinetic trials of trendione in humans.
Is Trenavar methylated? No. It lacks the 17-alpha-alkyl group associated with cholestatic liver injury in compounds such as Epistane and methylstenbolone.
Where does the trenbolone information come from? Bauer and colleagues in APMIS in 2000, Wilson and colleagues in Toxicological Sciences in 2002, and decades of veterinary growth promotion literature in cattle.
Can Trenavar be detected in a drugs test? Yes. Accredited laboratories detect trenbolone metabolites, and the compound is prohibited at all times by WADA.
Related reading
- Epistane (methylepitiostanol): the research
- SARMs versus prohormones
- M-Sten (methylstenbolone): the research record
- Third-party testing: how to read a certificate of analysis
- Browse the range: prohormones range
Research product: Alpha Labs Trenavar 20 mg, 90 capsules
Sources
Primary papers and official guidance cited in this guide, linked so each one can be checked directly.
- Bauer ER et al., APMIS 2000;108:838-846 (receptor affinity of trenbolone, trendione and other anabolic agents). PubMed 11252818
- Wilson VS et al., Toxicol Sci 2002;70:202-211 (in vitro and in vivo activity of 17-beta-trenbolone). PubMed 12441365
- Robinson JA et al., Environ Toxicol Chem 2017;36:613-620 (trendione as a trenbolone metabolite in cattle excreta). PubMed 27958649
- de Boer D et al., Biol Mass Spectrom 1991;20:459-466 (trenbolone and its human urinary metabolites in doping control). PubMed 1768702
- WADA Prohibited List 2026.