Cardarine (GW-501516) vs SR-9009 (Stenabolic): What the Research Shows

Research Use Only. The information below describes preclinical laboratory literature for educational and reference purposes. These compounds are not for human or veterinary use, and nothing here is a recommendation to administer, consume, or dose any substance.

Cardarine (GW-501516) and SR-9009 (Stenabolic) are two of the most frequently discussed compounds in the "exercise mimetic" research space. They are often grouped together because early animal studies linked both to changes in endurance, fat handling, and mitochondrial gene expression. Despite that shared reputation, they act through completely different molecular targets. This article compares what the published preclinical literature actually reports about each, how their proposed mechanisms differ, and why their regulatory status matters for anyone handling them in a laboratory setting.

What are Cardarine (GW-501516) and SR-9009?

Cardarine, also written GW-501516 or GW1516, is a synthetic small molecule developed in the 1990s as an agonist of the peroxisome proliferator-activated receptor delta (PPAR-delta, also called PPAR-beta/delta). It was originally investigated as a candidate for dyslipidemia and metabolic research before development was discontinued.

SR-9009, known by the research nickname Stenabolic, is a synthetic agonist of REV-ERB, a nuclear receptor that forms part of the circadian clock machinery. It was created as a chemical tool to probe how the body clock links to metabolism. The two compounds are sometimes shelved next to each other in research catalogs, but a PPAR-delta agonist and a REV-ERB agonist are pharmacologically distinct classes.

Where they sit in the research literature

Both compounds entered wider awareness through a small number of influential rodent studies. The most cited work on the PPAR-delta pathway comes from the Salk Institute, where researchers reported that a PPAR-delta agonist combined with training increased oxidative muscle fibers and running endurance in mice. SR-9009 reached attention through work at Scripps describing synthetic REV-ERB agonists that altered circadian and metabolic gene expression and increased energy expenditure in animal models.

Reported preclinical areas for Cardarine (GW-501516)

• Activation of PPAR-delta and downstream shifts in fatty acid oxidation gene expression in rodent skeletal muscle.
• Changes in muscle fiber type composition and treadmill running endurance in trained and untrained mice.
• Effects on serum lipid markers and lipoprotein handling in animal metabolic studies.
• Metabolomic signatures suggesting a shift toward fatty acid use and reduced glucose reliance, distinct from the changes seen with training alone.

Reported preclinical areas for SR-9009 (Stenabolic)

• Pharmacological activation of REV-ERB and modulation of core clock gene expression in the hypothalamus and peripheral tissues.
• Altered circadian patterns of metabolic gene expression in liver, skeletal muscle, and adipose tissue in mice.
• Reported increases in energy expenditure and reductions in fat mass in diet-induced obese animal models.
• Exploratory interest in mitochondrial content and exercise capacity in rodent models, an area still considered early and debated.

These points summarize what third-party researchers have reported in animal and in vitro systems. They are not findings in humans and are not claims of any benefit.

Chemistry and mechanism at a glance

The clearest way to separate these two compounds is by their molecular target and their handling profile.

• Molecular target: Cardarine acts on PPAR-delta, a transcription factor in the nuclear receptor family that regulates lipid and energy metabolism genes. SR-9009 acts on REV-ERB, a nuclear receptor that represses transcription and links the circadian clock to metabolism.
• Compound class: Cardarine is a thiazole-containing PPAR-delta agonist. SR-9009 is a pyrrolidine-based synthetic REV-ERB agonist.
• Reported half-life profile: SR-9009 is widely noted in the literature for poor oral bioavailability and a short pharmacokinetic profile, which is one reason its animal data are debated. Cardarine has been studied as an orally active agent in rodents.
• Typical research form: Cardarine is commonly supplied as capsules or powder for reconstitution, while SR-9009 is frequently handled as a solution in an oil-based carrier such as MCT oil because of its solubility characteristics.

Why the "research use only" label matters

Both Cardarine and SR-9009 are unapproved investigational chemicals. Neither has been authorized as a medicine by the European Medicines Agency or any comparable regulator, and neither has completed the clinical development that a licensed drug requires. In the European Union they are handled as laboratory reagents under chemical regulation, not as medicinal products. That classification only holds when they are described, sold, and used strictly for research, without any human or veterinary use framing.

Regulatory and safety note: both compounds are prohibited in sport by the World Anti-Doping Agency. Cardarine (GW-501516) additionally carries a well-documented safety flag because its original development program was halted after long-term rodent studies reported the formation of tumors across multiple organs. SR-9009 is listed among non-approved substances that are banned at all times in sport. Neither should be treated as safe for use in living subjects.

Handling and storage for researchers

General good laboratory practice applies to both compounds. Lyophilized or powdered material is typically kept sealed and protected from light, heat, and moisture until it is prepared for an experiment. Once a solid is reconstituted, or when a compound is supplied pre-dissolved in a carrier, refrigeration and protection from repeated temperature swings help preserve integrity. Oil-based solutions such as an MCT carrier are handled differently from aqueous peptide solutions, so researchers should follow the specific storage guidance for each format. For a fuller walkthrough of best practices, see our peptide storage and stability laboratory guide.

Frequently asked questions

Are Cardarine and SR-9009 the same type of compound?

No. They are often mentioned together as exercise mimetics, but Cardarine is a PPAR-delta agonist and SR-9009 is a REV-ERB agonist. These are separate nuclear receptor targets with different downstream biology.

Are either of these approved for human use?

No. Neither Cardarine nor SR-9009 is an approved medicine in the EU, the United States, or elsewhere. Both remain investigational research chemicals, and Cardarine development was discontinued after rodent safety findings.

Is Cardarine or SR-9009 legal to buy for research in the EU?

Within the European Union, unapproved research chemicals like these are generally handled as laboratory reagents under chemical legislation and may be supplied for bona fide research use only. They may not be marketed for human or veterinary consumption. Requirements can vary by member state, so researchers are responsible for confirming the rules that apply in their own country and institution.

Why is SR-9009 data considered more debated than Cardarine data?

Independent researchers have highlighted that SR-9009 shows poor oral bioavailability and a short half-life in animals, which raises questions about how its reported effects translate. This does not make either compound suitable for use in living subjects, but it is a reason the two are studied and interpreted differently.

Can these be used in sport or by athletes?

No. Both are on the World Anti-Doping Agency prohibited list. Their presence in the research market is separate from sport, and this article does not address or endorse any such use.

Key takeaways

• Cardarine (GW-501516) and SR-9009 (Stenabolic) are grouped as exercise mimetics but act on different targets: PPAR-delta versus REV-ERB.
• The most cited data for each come from rodent and in vitro studies of endurance, metabolism, and circadian gene expression.
• SR-9009 is often described as having poor bioavailability, which is one reason its animal data are debated.
• Both are unapproved, both are banned in sport, and Cardarine carries an additional rodent carcinogenicity safety flag.
• In the EU they are handled strictly as research use only laboratory reagents, never as products for human or veterinary use.

References

References sourced via PubMed.

1. Narkar VA, Downes M, Yu RT, et al. AMPK and PPARdelta agonists are exercise mimetics. Cell. 2008;134(3):405-415. https://doi.org/10.1016/j.cell.2008.06.051 | https://pubmed.ncbi.nlm.nih.gov/18674809/
2. Chen W, Gao R, Xie X, et al. A metabolomic study of the PPARdelta agonist GW501516 for enhancing running endurance in Kunming mice. Sci Rep. 2015;5:9884. https://doi.org/10.1038/srep09884 | https://pubmed.ncbi.nlm.nih.gov/25943561/
3. Solt LA, Wang Y, Banerjee S, et al. Regulation of circadian behaviour and metabolism by synthetic REV-ERB agonists. Nature. 2012;485(7396):62-68. https://doi.org/10.1038/nature11030 | https://pubmed.ncbi.nlm.nih.gov/22460951/

Related reading: Exercise Mimetics: PPAR, REV-ERB and ERR Research Compounds Overview, Cardarine (GW-501516): What the Research Shows, and SR-9009 (Stenabolic): What the Research Shows. Research forms of these compounds are available in our catalog: Cardarine (GW-501516) capsules and SR-9009 MCT oil solution.

Disclaimer: Research Use Only. Not for human or veterinary use. This content is provided for scientific and educational reference and does not constitute medical, health, or usage advice. Pure Chems does not sell these compounds for consumption and makes no therapeutic claims.