Updated September 2026. SR-9009 is sold by SARMs Store strictly as a research compound. Nothing on this page is medical advice or an instruction for human use.
Stenabolic, coded SR-9009, is sold alongside SARMs and is not one. It does not bind the androgen receptor and it was never developed for muscle or bone. It is a chemical probe built to study the circadian clock, and it became a research chemical product because one mouse study produced results that looked extraordinary. Since then the scientific picture has become considerably more complicated, in ways most product pages do not mention. This guide sets out the original findings, the two problems that emerged afterwards, and where UK law stands in 2026.
What SR-9009 is
SR-9009 is a synthetic agonist of REV-ERB, a nuclear receptor that acts as a transcriptional repressor and forms part of the molecular machinery of the circadian clock. REV-ERB alpha and REV-ERB beta regulate the daily rhythm of large numbers of genes, including many involved in lipid and glucose metabolism and in mitochondrial function in skeletal muscle. Activating REV-ERB pharmacologically alters metabolic gene expression, which is why it attracted interest as a metabolic research tool.
SR-9009 does not act on androgen receptors, so it does not suppress testosterone and has no anabolic mechanism comparable to Ostarine or LGD-4033. Calling it a SARM is simply incorrect. The correct description is a REV-ERB agonist, and the compound it belongs alongside is Cardarine (GW-501516), a PPAR-delta agonist, which is also not a SARM and also ended up in the same retail bucket.
What the research found
The original mouse study (Solt and colleagues, Nature, 2012). This is the paper behind every claim made about Stenabolic. The authors developed SR-9009 and its close analogue SR-9011 as synthetic REV-ERB agonists and gave them to mice by intraperitoneal injection. In diet-induced obese mice the compounds reduced fat mass and improved the plasma lipid profile without a change in food intake, altered circadian behaviour and core clock gene expression, and increased markers of mitochondrial content in skeletal muscle. A widely quoted follow-up reported increased exercise capacity in treated mice, the source of the “exercise in a bottle” description that has followed the compound ever since.
Taken at face value that is striking. Two later developments complicate it.
The mechanism problem (Dierickx and colleagues, Proceedings of the National Academy of Sciences, 2019). This group tested SR-9009 in cells that had been genetically stripped of both REV-ERB alpha and REV-ERB beta. The compound still produced effects on cell metabolism and gene expression in those cells, which it could not do if it were working through REV-ERB. The conclusion was that a substantial part of SR-9009’s observed activity is independent of its supposed target, in other words off-target. That does not erase the original findings, but it does mean the tidy mechanistic story attached to the compound is no longer secure, and that the source of its effects is not fully identified.
The bioavailability problem. In the original pharmacology work SR-9009 showed very poor oral bioavailability in rodents, in the region of two per cent, which is why the animal studies used injection. A compound barely absorbed when swallowed is a difficult fit for an oral capsule product, and this is the most practically important fact on this page. The animal results came from a route of administration oral material does not replicate.
There are no human trials of SR-9009 at any phase. No clinical efficacy or safety data exist.
Doses used in the research
For reference only: the published mouse work used doses in the range of tens of milligrams per kilogram of body weight per day, administered by intraperitoneal injection rather than by mouth, typically over days to weeks. Because oral bioavailability was very low and no human pharmacokinetic study exists, those figures cannot be translated into an oral human dose in any defensible way. Research material is commonly supplied at 8 mg per capsule. SARMs Store does not sell SR-9009 for human consumption.
Side effects reported
The mouse studies did not report acute toxicity at the doses used, and the treated animals did not show reduced food intake or obvious distress. Beyond that, there is very little to report, because the studies were short, in rodents, and not designed as safety studies.
No human side effect profile exists. Because SR-9009 does not act on the androgen receptor, the hormonal effects documented for SARMs are not expected and have not been described. What can reasonably be flagged comes from the mechanism itself. REV-ERB sits at the centre of circadian regulation, and the animal work showed altered sleep and activity patterns in treated mice. A compound that changes the clock in a whole organism is not a trivial intervention, and the 2019 off-target finding means the full range of what it does is not mapped. Nobody knows what SR-9009 does in a human body, because nobody has published a study that looked.
SR-9009 compared with Cardarine and the SARMs
The closest comparison is Cardarine (GW-501516), which is also not a SARM, also targets metabolism rather than the androgen receptor, and also produced striking endurance results in mice. The difference is depth of record: Cardarine reached human trials and carries a well documented carcinogenicity finding in long-term rodent studies, whereas SR-9009 has neither human data nor long-term animal data. Ostarine and LGD-4033 have human trials and a described hormonal side effect profile; SR-9009 has neither. Grouping all four together is a shelf arrangement, not a pharmacological one.
Legal status in the UK, 2026
SR-9009 is not a controlled substance under the Misuse of Drugs Act 1971 and is not a Class C anabolic steroid, which is unsurprising given that it is not a steroid or an androgen at all. Under the Human Medicines Regulations 2012 it is an unlicensed medicinal product if sold, supplied or advertised for human use, and the MHRA enforces that, so UK suppliers list it strictly for laboratory research. In sport it is prohibited at all times by WADA under section S4.5 as a metabolic modulator, the same section that covers Cardarine and AICAR, and UK Anti-Doping applies the same list. Anti-doping laboratories have published detection methods for SR-9009 and its metabolites.
How to check a supplier
Ask for the certificate of analysis matching the batch number on the bottle, showing identity by HPLC or LC-MS and a stated purity figure, rather than a generic PDF. Check the label for compound name, milligrams per capsule, capsule count, batch number and a research-only notice. UK manufacturing keeps the chain short enough to audit. Dexterz Labs Stenabolic SR-9009 is made in the UK at 8 mg per capsule, 90 capsules per bottle, and every batch is independently tested with its certificate of analysis published on the product page.
Frequently asked questions
Is SR-9009 a SARM? No. It is a REV-ERB agonist. It has no activity at the androgen receptor and is sold alongside SARMs by convention only.
Does SR-9009 suppress testosterone? There is no mechanism by which it would, and no study has reported it doing so.
Why is oral bioavailability an issue? The original pharmacology reported very low oral bioavailability in rodents, around two per cent, and the animal studies used injection. Oral capsules do not reproduce that exposure.
Did the 2019 study disprove SR-9009? Not exactly. Dierickx and colleagues showed that SR-9009 still acts on cells lacking both REV-ERB proteins, which means much of its activity is off-target and its mechanism is not what was assumed.
Are there human studies of SR-9009? No. There are no published human trials of any phase.
Is SR-9009 legal in the UK? It is not a controlled drug. It is an unlicensed medicine if sold for human use, and it is banned in sport as a metabolic modulator.
Related reading
- Cardarine (GW-501516): what the research shows
- Ostarine (MK-2866): the complete research guide
- SARMs for fat loss: what the studies actually found
- Are SARMs legal in the UK? 2026 update
Research product: Dexterz Labs Stenabolic SR-9009 8 mg, 90 capsules
Related peptides in the research
The metabolic and endurance literature runs alongside a separate set of peptides: NAD+, studied in mitochondrial and ageing models, 5-Amino-1MQ, an NNMT inhibitor studied in adipose tissue, and HGH Fragment 176-191, the lipolytic fragment of growth hormone. Guide: NAD+: what the research says. For how SARMs and peptides differ in mechanism, evidence and storage, read SARMs vs peptides. Full range: Origin Peptides range.
Sources: Solt LA et al., Nature 2012;485:62-68. Dierickx P et al., Proc Natl Acad Sci U S A 2019;116:12147-12152. WADA Prohibited List 2026, section S4.5. No human trials of SR-9009 have been published as of September 2026.