For laboratory research use only. Not for human consumption. All compounds referenced in this article are sold by Explicit SARMs solely as reference materials for in-vitro and animal research by qualified professionals. Nothing here is medical advice, and no statement has been evaluated by the FDA. These materials are not intended to diagnose, treat, cure or prevent any disease.
GW-501516, also written GW1516 and widely sold under the name Cardarine, is often grouped with SARMs in research catalogs. That grouping is a convention of the market, not of pharmacology. GW-501516 does not bind the androgen receptor at all. It is a selective agonist of peroxisome proliferator-activated receptor delta (PPAR-delta, also called PPAR-beta/delta), a nuclear receptor that regulates fatty acid metabolism and energy use.
This review covers the mechanism, research history, published findings and the serious toxicology record that ended its clinical development, along with handling and documentation notes. Explicit SARMs supplies GW-501516 Cardarine Capsules and GW-501516 Liquid strictly as laboratory reference material.
What Is GW-501516?
- Common names: GW-501516, GW1516, GSK-516, Cardarine
- Class: selective PPAR-delta agonist (not a selective androgen receptor modulator)
- Primary target: PPAR-delta nuclear receptor
- Originator: GlaxoSmithKline, from a collaboration with Ligand Pharmaceuticals in the 1990s
- Regulatory status: never approved by the FDA or any other regulator; clinical development stopped
Mechanism of Action
PPARs are ligand-activated transcription factors in the nuclear receptor superfamily. There are three subtypes: PPAR-alpha (the target of fibrate drugs), PPAR-gamma (the target of thiazolidinediones), and PPAR-delta. When an agonist binds PPAR-delta, the receptor pairs with the retinoid X receptor (RXR), binds PPAR response elements on DNA, and changes transcription of genes involved in fatty acid uptake, transport and beta-oxidation, as well as cholesterol efflux.
GW-501516 was notable for its high potency and selectivity for PPAR-delta over the alpha and gamma subtypes, which made it a useful tool compound for separating PPAR-delta biology from that of the other two receptors. [1]
Because it acts on a completely different receptor, none of the androgen-receptor concepts used for SARMs, such as tissue-selective AR activation or HPG-axis suppression, apply to GW-501516. Researchers comparing it with true SARMs such as Ostarine should treat it as a separate pharmacological class.
Research History
GW-501516 was described in a 2001 paper in the Proceedings of the National Academy of Sciences. [1] GSK then developed it as a candidate for dyslipidemia and related metabolic conditions, and it entered phase 1 and phase 2 clinical studies.
In 2006, GSK stopped all development after long-term rodent toxicology studies found tumors in multiple organs. In 2013, the World Anti-Doping Agency took the unusual step of issuing a public alert about the compound, stating that it had been withdrawn from development because of serious toxicities found in preclinical studies and that clinical approval “has not, and will not be given.” [6]
What Published Studies Report
Primate and rodent work
The original 2001 PNAS study reported that GW-501516 increased HDL cholesterol and lowered triglycerides, LDL and fasting insulin in obese rhesus monkeys, and increased expression of the cholesterol efflux transporter ABCA1 in cell models. [1]
A 2008 paper in Cell by Narkar and colleagues studied GW-501516 and the AMPK activator AICAR in mice. The authors reported that PPAR-delta activation increased oxidative gene expression in skeletal muscle and that the effects were enhanced in combination with exercise training, while AICAR alone acted on similar pathways. The paper described both agents as “exercise mimetics” in that mouse context. [2]
Early clinical research
Small, short phase 1 studies were published before development stopped. Sprecher and colleagues reported changes in the triglyceride-to-HDL ratio in healthy subjects. [3] Riserus and colleagues reported reductions in plasma triglycerides, apolipoprotein B, LDL cholesterol and liver fat content, along with increased fatty acid oxidation in skeletal muscle, in moderately obese men over a two-week period. [4] These studies were too short and too small to assess long-term safety, which is why the rodent carcinogenicity data were decisive.
Toxicology
The decisive finding in the GW-501516 record is preclinical carcinogenicity. GSK reported tumors across multiple organs in long-term rodent studies, and WADA cited those toxicities in its 2013 alert. [6] Any research summary of GW-501516 that omits this history is incomplete.
Research Considerations
- Classify correctly. Treat GW-501516 as a PPAR-delta tool compound, not a SARM, and choose controls and endpoints accordingly.
- Subtype selectivity. When attributing effects to PPAR-delta, consider PPAR-delta antagonists or knockout models to confirm on-target activity.
- Long-term exposure endpoints. Given the carcinogenicity history, chronic animal studies require careful histopathology and institutional oversight.
- Metabolite analysis. Thevis and colleagues have published synthesis and mass spectrometric characterization of GW-501516 and its major metabolites, which is useful for method development. [5]
- Safety handling. Treat the material as a potential carcinogen in the lab: gloves, eye protection, a fume hood or ventilated enclosure for powders, and documented waste disposal.
How GW-501516 Differs From SARMs
The practical consequences of GW-501516’s classification are easy to overlook, so they are worth stating directly:
- Different receptor. PPAR-delta is a lipid-sensing nuclear receptor that partners with RXR. SARMs act on the androgen receptor, which forms homodimers and binds different DNA response elements.
- Different gene programs. PPAR-delta targets include genes for fatty acid transport and oxidation, such as CPT1 and PDK4, and cholesterol efflux genes such as ABCA1. [1] Androgen receptor targets are largely different.
- Different safety record. The defining toxicology issue for GW-501516 is rodent carcinogenicity, while the recurring signals for SARMs are lipid changes, hormonal suppression and hepatic effects.
- Different WADA section. GW-501516 is listed under S4.4 Metabolic Modulators, not S1.2 Anabolic Agents. [7]
Researchers who need a PPAR-delta tool compound for mechanistic work will find a substantial literature on GW-501516. Researchers who need an androgen receptor ligand should look elsewhere in the catalog.
WADA Status
PPAR-delta agonists, including GW-501516, are prohibited at all times under WADA section S4.4 (Metabolic Modulators). [7]
Storage, Purity and COA
- Store sealed, protected from light and moisture, at controlled room temperature or cooler.
- Keep the liquid format tightly capped to prevent solvent evaporation.
- Label and log every container with lot number and date of receipt.
- Review the lot-specific Certificate of Analysis, which should report HPLC purity, confirm identity by mass spectrometry, and list the lot number and analysis date.
For lot documentation, use the contact page.
Related Research Compounds
- SR 9009 Stenabolic Capsules, a REV-ERB agonist also studied in metabolic research (see the SR9009 research overview)
- SLU-PP-332 Capsules, an estrogen-related receptor agonist studied in metabolic models
- BAM15, a mitochondrial uncoupler used in metabolic research
- Ostarine MK-2866 capsules, a nonsteroidal SARM often compared alongside PPAR research compounds; MK-777 (acetamoren) capsules, an N-acetyl analog of ibutamoren used in GHS-R1a research
- Class overview: SARMs vs Traditional Research Compounds and the SARMs collection
Frequently Asked Questions
Is GW-501516 a SARM?
No. GW-501516 is a PPAR-delta agonist. It does not bind the androgen receptor. It is sold alongside SARMs by convention only.
Why was GW-501516 development stopped?
GSK stopped development in 2006 after long-term rodent studies found tumors in multiple organs. WADA later cited those toxicities in a public alert. [6]
Is GW-501516 approved by the FDA?
No. It has never been approved by the FDA or any other regulator, and WADA has stated that clinical approval will not be given. [6]
What did the published clinical studies measure?
Small phase 1 studies measured lipid and metabolic markers, such as triglycerides, HDL, apolipoprotein B and liver fat, over short periods. [3][4]
Is GW-501516 prohibited in sport?
Yes. PPAR-delta agonists are prohibited at all times under WADA section S4.4. [7]
Why is it called Cardarine?
Cardarine is a market name with no scientific or regulatory standing. GW-501516 and GW1516 are the designations used in the literature.
What is GW-501516 used for in research today?
It is used mainly as a selective PPAR-delta tool compound in cell and animal studies of lipid metabolism, mitochondrial gene expression and cholesterol efflux, and as an analytical target in anti-doping method development. [1][2][5]
Does GW-501516 have any approved medical use?
No. GSK ended development in 2006, and no regulator has approved it for any indication. [6]
References
- Oliver WR Jr, et al. A selective peroxisome proliferator-activated receptor delta agonist promotes reverse cholesterol transport. Proc Natl Acad Sci U S A. 2001. PubMed 11309497
- Narkar VA, et al. AMPK and PPARdelta agonists are exercise mimetics. Cell. 2008. PubMed 18674809
- Sprecher DL, et al. Triglyceride:high-density lipoprotein cholesterol effects in healthy subjects administered a peroxisome proliferator activated receptor delta agonist. Arterioscler Thromb Vasc Biol. 2007. PubMed 17110604
- Riserus U, et al. Activation of peroxisome proliferator-activated receptor (PPAR)delta promotes reversal of multiple metabolic abnormalities, reduces oxidative stress, and increases fatty acid oxidation in moderately obese men. Diabetes. 2008. PubMed 18024853
- Thevis M, et al. Synthesis, mass spectrometric characterization, and analysis of the PPAR-delta agonist GW1516 and its major human metabolites: targets in sports drug testing. Methods Mol Biol. 2013. PubMed 23100242
- World Anti-Doping Agency. WADA issues alert on GW501516. March 21, 2013. wada-ama.org
- World Anti-Doping Agency. 2026 Prohibited List. wada-ama.org
For laboratory research use only. Not for human consumption. All compounds referenced in this article are sold by Explicit SARMs solely as reference materials for in-vitro and animal research by qualified professionals. Nothing here is medical advice, and no statement has been evaluated by the FDA. These materials are not intended to diagnose, treat, cure or prevent any disease.
Explicit SARMs supplies GW-501516 cardarine capsules for laboratory work. For an androgen receptor ligand with phase 2 clinical data, see ostarine MK-2866 capsules.