Commonly combined with GW-501516 (Cardarine) in research protocols.
Ratings are based on published research data and are for informational purposes only.
Cardarine is a PPARδ agonist, not a SARM. It enhances fatty acid oxidation and mitochondrial biogenesis. Preclinical data shows endurance enhancement and improved lipid profiles. Note: GlaxoSmithKline halted development after carcinogenicity signals in rodent studies at high doses.
Research Post
Cardarine (GW-501516) is a synthetic PPARδ (Peroxisome Proliferator-Activated Receptor delta) agonist developed jointly by GlaxoSmithKline and Ligand Pharmaceuticals. It is often grouped with SARMs in the research chemical space, but operates through an entirely different mechanism — it does not bind to the androgen receptor.
PPARδ is a nuclear receptor that, when activated, regulates genes involved in fatty acid oxidation, glucose metabolism, and mitochondrial biogenesis. GW-501516 acts as a full agonist at PPARδ, upregulating genes including CPT1B, ABCA1, and PDK4 — collectively driving a metabolic shift towards fat as the primary energy substrate.
In skeletal muscle, PPARδ activation increases oxidative fibre content and mitochondrial density, producing endurance-enhancing effects independent of training. In adipose tissue, GW-501516 promotes lipolysis and reduces fat accumulation. In lipid metabolism, it raises HDL cholesterol and lowers LDL and triglycerides — findings confirmed in human trials.
GlaxoSmithKline conducted multiple Phase I trials with GW-501516. Published trial data documents significant improvements in HDL cholesterol, reductions in LDL cholesterol, reduced fasting insulin, and reduced triglycerides in overweight subjects over 2 weeks at doses of 2.5–10 mg/day (Sprecher et al., 2007). These findings established the lipid-modulating effects of PPARδ agonism in humans.
GSK discontinued the GW-501516 programme in 2007 after carcinogenicity signals emerged in preclinical long-term rodent studies. Animals exposed to very high doses over extended durations showed accelerated tumour development across multiple tissues. GSK concluded the risk/benefit profile was incompatible with continued pharmaceutical development.
The carcinogenicity findings from GSK's rodent studies are the defining safety concern for GW-501516 research. The mechanism proposed involves PPARδ-mediated promotion of cell proliferation in pre-cancerous cells. Critically, GW-501516 does not appear to initiate tumour formation de novo, but to accelerate the progression of pre-existing neoplastic cells. The doses used in rodent studies were substantially higher than those in the human lipid-modulating trials. Whether these findings translate to meaningful risk at lower doses in short-duration research protocols remains an open question in the scientific literature.
No. GW-501516 is a PPARδ agonist, not a SARM. It does not bind to the androgen receptor and its mechanism of action is entirely distinct from SARMs. It is grouped with SARMs in research chemical catalogues due to overlapping research contexts, not pharmacological similarity.
GSK observed accelerated tumour development across multiple tissues in high-dose, long-duration rodent carcinogenicity studies. The risk/benefit calculation was unfavourable for continued pharmaceutical development. The programme was discontinued in 2007. These findings are a critical consideration for any research protocol involving GW-501516.
No. Because it acts via PPARδ rather than the androgen receptor, GW-501516 does not suppress the HPT axis or endogenous testosterone production. Post-cycle androgenic support is not a consideration when researching GW-501516 in isolation.
