SR9009 (Stenabolic): REV-ERB research and the bioavailability problem

People searching "SR9009", "Stenabolic" or "what does SR9009 do" have usually met it in a SARMs shop or a forum thread, described as an exercise mimetic. The accurate answer is narrower. SR9009 is a laboratory tool compound that activates REV-ERB, a pair of circadian clock receptors, and almost everything known about it comes from injected mice and cultured cells. It has never been in a clinical trial, and two recent case reports describe serious liver injury in people who took products sold under its name. This guide covers what it is, how it is thought to work, what studies measured, why injected-mouse results say little about an oral capsule, and its UK and sport status. It contains no guidance on use.

What is SR9009?

SR9009 is a synthetic small molecule designed at the Scripps Research Institute in Jupiter, Florida, and first described in 2012 together with a sister compound, SR9011 (Solt et al., 2012). It is also written SR-9009 or SR 9009 and is sold as "Stenabolic", a market name rather than a pharmaceutical brand. It was made as a probe for studying REV-ERB in animals, and it has never undergone clinical evaluation in humans or been approved as a medicine anywhere (Shams Bin Shaheen et al., 2026).

Is SR9009 a SARM or a peptide?

Neither. It is not an androgen receptor ligand: a 2020 review records that SR9009 and SR9011 showed no effects on 46 other nuclear receptors in cell assays (Wang et al., 2020). It sits next to SARMs only because the same shops sell it. It is not a peptide either: it is a small organic molecule made by chemical synthesis, not a chain of amino acids.

How SR9009 is thought to work

REV-ERBα and its close relative REV-ERBβ are nuclear receptors that act as transcriptional repressors: when active, they switch genes off rather than on (Wang et al., 2020). Their endogenous ligand is heme (Dierickx et al., 2019). They sit inside the molecular clock that runs in most tissues, repressing core clock genes such as BMAL1 and, through the clock, shaping daily rhythms in fat metabolism, glucose production in the liver and inflammation. That link between the clock and metabolism is why REV-ERB was first proposed as a drug target for sleep disorders and metabolic disease (Wang et al., 2020).

SR9009 was designed to bind REV-ERB and strengthen that repression. In muscle, the proposed route runs through mitochondria: a 2013 study found REV-ERBα highly expressed in oxidative skeletal muscle, and mice lacking it there had fewer mitochondria and reduced exercise capacity, while raising its activity did the opposite (Woldt et al., 2013). The difficulty, covered below, is that SR9009 does not appear to act only through REV-ERB.

What the research reports

Metabolism and circadian behaviour in mice

The 2012 Nature paper that introduced SR9009 and SR9011 reported that a single injection of either compound abolished the next active period in mice kept in constant darkness, and that the compounds changed the daily pattern of clock and metabolic gene expression in liver, skeletal muscle and fat. In diet-induced obese mice given SR9009 by repeated intraperitoneal injection for 30 days, fat mass fell, and fasting triglycerides, cholesterol, free fatty acids and glucose were lower than in vehicle-treated controls, with no significant difference in food intake (Solt et al., 2012). Two details are rarely repeated. Handling and injection stress made the control mice lose weight too, and SR9009-treated mice lost 60 per cent more than those controls, not 60 per cent of their weight. And the rise in oxygen consumption shown in the paper was measured with SR9011, not SR9009.

Endurance in mice

The endurance reputation traces to the 2013 Nature Medicine study. Mice treated with SR9009 by intraperitoneal injection for 30 days ran significantly longer, in both time and distance, than vehicle-treated mice on a treadmill, and cultured muscle cells exposed to SR9009 or SR9011 showed increased mitochondrial content (Woldt et al., 2013). The treadmill comparison used six mice per group, and the study concerned oxidative capacity, not muscle growth.

The mechanism question in cells

In 2019 a University of Pennsylvania group tested SR9009 on liver cells and embryonic stem cells from mice lacking both REV-ERBα and REV-ERBβ. SR9009 still decreased cell viability, rewired cellular metabolism and altered gene transcription (Dierickx et al., 2019). The authors concluded that its effects cannot be used solely as a surrogate for REV-ERB activity, and the mechanism behind these REV-ERB-independent effects remains unknown (Wang et al., 2020).

Reports in people

There are no human trials. The only human data we found are two liver case reports. In 2025, US clinicians described a 40-year-old man with hepatocellular liver injury after he started a product sold as Stenabolic. Infection and autoimmune causes were ruled out, a standard causality score (RUCAM) placed the link in the "probable" range, and he improved after stopping. He was also taking several other supplements, no liver biopsy was performed, and the authors could not exclude contamination with other compounds (Govil et al., 2025). In 2026, Australian clinicians reported a previously healthy 17-year-old who developed acute liver failure about three months after finishing a course of oral SR9009 bought online. He reported no other supplements. Viral, autoimmune, metabolic and obstructive causes were excluded, a biopsy showed severe hepatocellular necrosis, and he needed an emergency liver transplant (Shams Bin Shaheen et al., 2026).

Case reports cannot prove cause, and neither describes chemical analysis of the product taken. They do show that serious liver injury has been recorded after exposure to products sold under this name.

The bioavailability problem

Bioavailability is the fraction of a compound that reaches the circulation intact; for anything swallowed, it depends on gut absorption and on how much the liver breaks down first. It is the largest gap between the SR9009 literature and the SR9009 market.

• The headline results used injection. The metabolic and endurance studies gave SR9009 by intraperitoneal injection, which avoids absorption from the gut (Solt et al., 2012; Woldt et al., 2013). The original authors called their pharmacokinetic properties sufficient for in vivo study, a statement about injected mice, not oral use.
• The class is cleared quickly. A 2020 review named suboptimal pharmacokinetics with poor bioavailability as a possible limiting factor for REV-ERB ligands, which are cleared rapidly, with half-lives under three hours, so animal studies relied on repeated daily injection. The authors judged rapid clearance in humans highly possible too (Wang et al., 2020).
• Successors were built to improve on it. The same review describes SR12418, made by modifying the structure of SR9009, as having better pharmacokinetic properties than SR9009 (Wang et al., 2020).
• No human data. The authors of the 2026 case report wrote that there are no published data on SR9009's pharmacokinetics, long-term safety or hepatotoxic potential (Shams Bin Shaheen et al., 2026).
• Mice are nocturnal. Their activity-rest cycle is the reverse of ours, and the 2020 review raised serious concerns about whether clock functions defined in mice carry over to people (Wang et al., 2020).

We have not found a published study measuring how much of an oral SR9009 capsule reaches the circulation in people. A capsule is not a smaller version of the injected-mouse experiment, and those results cannot be transferred to it.

Legal and regulatory status

United Kingdom

SR9009 is not a licensed medicine in the UK and has no MHRA marketing authorisation. It is not an authorised food supplement or novel food and may not be sold for human consumption. It is not listed as a controlled drug under the Misuse of Drugs Act 1971. It is supplied for laboratory research to adults aged 18 and over, which is the only basis on which it appears in our SR9009 collection. Orders ship with free tracked UK delivery in plain packaging.

European Union and United States

No EU marketing authorisation or novel food authorisation exists, and buyers in EU countries are responsible for their own national import rules. In the US it has never been approved by the FDA for any use and has no recognised status as a dietary supplement ingredient. At the time of the 2020 review, no REV-ERB ligand had progressed to clinical trials (Wang et al., 2020).

WADA and sport testing

SR9009 is named in section S4.4 of the WADA Prohibited List, metabolic modulators, in the same subsection as AICAR and GW1516, and is prohibited at all times, in and out of competition. That applies to any athlete in a code-compliant anti-doping programme, including UK Anti-Doping's. We have not found a verified human excretion study that establishes how long SR9009 or its metabolites stay detectable, so we give no window: the accurate position is detectable, window not established. Anyone subject to testing should read the current list itself.

Common questions

SR9009 vs SR9011: what is the difference?

SR9011 is the sister compound from the same 2012 paper. Both were derived from an earlier REV-ERB probe, GSK4112, and act on the same receptors (Wang et al., 2020). SR9011 carried the oxygen consumption work while SR9009 was used in the obese-mouse study (Solt et al., 2012). Neither has human trial data, and SR9011 is not stocked here.

Stenabolic vs cardarine

Both are sold as metabolic research compounds, but they are unrelated molecules acting on different receptors.

The cardarine evidence is referenced in Cardarine (GW-501516): why development stopped; brands held are in the Cardarine collection.

Is SR9009 safe, and what side effects have been reported?

Nobody can say it is, because it has never been assessed in a clinical study. The reported side effects are the two liver cases above. We do not describe any research compound as safe.

Does SR9009 work? Benefits, dosage, timing and before-and-after

No human study shows whether it does anything in people, so there is no answer to how long it takes either. We do not publish dosing, cycle, timing or outcome guidance and make no claim about what SR9009 does in people. Before-and-after posts cannot show what was in the product or what else changed.

What do Reddit threads tell you?

Forum reports come from people who cannot know what they bought or how much was absorbed; in the 2025 case, even clinicians could not rule out other compounds (Govil et al., 2025). Anecdotes are evidence neither of effect nor of harmlessness.

What does SR9009 cost?

Prices change, so we do not quote them in articles. Compare listings on total milligrams against price: the listing we stock is labelled 10mg per capsule, 60 capsules, 600mg in total. The price per milligram guide explains the method.

How to verify a batch of SR9009

Batch documentation is the one content check a buyer can make. A certificate of analysis should identify the compound by HPLC or LC-MS against a reference standard, state purity as a percentage, give the measured content against the labelled strength, carry a batch number that matches the pack, and name the laboratory and test date. Purity without identity proves nothing, and a generic brand PDF without a batch number is not a batch certificate.

The only SR9009 we currently stock is the iMuscle Stenabolic SR-9009 listing. iMuscle is a third-party brand, so a certificate is shown only where the manufacturer supplies one for the batch we hold. There is no Free Muscle-brand SR9009, so the Janoshik Analytical testing applied to every Free Muscle-brand batch does not cover this compound. Contact us and we will send what we hold for your batch, or say plainly that there is none. See How to Read a Certificate of Analysis, the lab tests page and our UK supplier checklist.

Related reading

• SR9009 (Stenabolic) collection: every brand stocked, compared.
• SLU-PP-332 and 5-Amino-1MQ: mouse data only and the SLU-PP-332 collection.
• What Are SARMs? The 2026 Research Guide
• iMuscle range and Cardarine (GW-501516) collection.

SR9009 is sold for laboratory research use only. It is not a licensed medicine, has not been evaluated by the MHRA, EMA or FDA, is not a food supplement and is not for human consumption. Products are supplied to adults aged 18 and over. Nothing on this page is medical advice or dosing, cycle or usage guidance. Summaries of published studies describe what researchers reported in animals, cells or individual patients and are not claims about any product.

References

1. Solt LA, et al. Regulation of circadian behaviour and metabolism by synthetic REV-ERB agonists. Nature. 2012;485(7396):62-68. PMID: 22460951.
2. Woldt E, et al. Rev-erb-α modulates skeletal muscle oxidative capacity by regulating mitochondrial biogenesis and autophagy. Nat Med. 2013;19(8):1039-1046. PMID: 23852339.
3. Dierickx P, et al. SR9009 has REV-ERB-independent effects on cell proliferation and metabolism. Proc Natl Acad Sci U S A. 2019;116(25):12147-12152. PMID: 31127047.
4. Wang S, et al. Targeting REV-ERBα for therapeutic purposes: promises and challenges. Theranostics. 2020;10(9):4168-4182. PMID: 32226546.
5. Govil D, et al. When Gains Go Wrong: A Case of Selective Androgen Receptor Modulator-Related Liver Injury. Cureus. 2025;17(7):e87376. PMID: 40765588.
6. Shams Bin Shaheen S, et al. Acute Liver Failure in an Adolescent Following Use of the Synthetic REV-ERB Agonist SR9009. Case Reports Hepatol. 2026;2026:9926772. PMID: 42750938.