RESEARCH MONOGRAPH · KDC-MN-265

Cardarine (GW-501516)

May 9, 2026 Kodiac biolabs Research Revised May 30, 2026 3 min read

Our opinion on this compound

52/100

Not a SARM, real PPAR-delta agonist, and abandoned because of cancer signals nobody likes to mention

Look, cardarine has the worst marketing problem of any compound in this batch. It's not a SARM, the bodybuilding scene started calling it one, and the underlying compound has a development history that ended for very specific reasons that anyone using it as a research tool should know cold.

GW-501516 is a high-affinity PPAR-delta agonist developed by GlaxoSmithKline and Ligand Pharmaceuticals in the 90s and early 2000s for dyslipidemia and metabolic indications. The preclinical data on lipid profiles, endurance, and fatty acid oxidation was genuinely interesting; PPAR-delta drives a transcriptional program that shifts muscle toward oxidative metabolism. The Evans lab and others showed striking effects on running endurance in mice.

The reason GSK shut the program down was the carcinogenicity data. Multi-organ tumor induction (liver, bladder, testes, thyroid, others) appeared in two-year rodent studies at doses that werent enormous relative to the planned clinical exposures, and the development program was terminated in 2007. WADA banned it in 2009 specifically because of the cancer risk, not just because of the performance-enhancing potential.

The mechanism is well-characterized and the basic biology is interesting. PPAR-delta as a target for metabolic disease and exercise mimetics is a real research area, and there are newer PPAR-delta agonists in development with hopefully better safety profiles. As a research tool for studying PPAR-delta signaling, GW-501516 is one of the standard reference ligands.

What we dont like is everything about how it ended up in the consumer scene. The endurance benefits in animal models are real, the lipid effects are real, and the gray-market vendors have spent a decade marketing those benefits while either downplaying or omitting the carcinogenicity signal. That's not science, that's negligence.

For legitimate research use the compound is fine as an in vitro PPAR-delta agonist, and limited short-term in vivo work in appropriate models is defensible. Anyone using it should know the rodent oncology data cold and design accordingly. The implication isnt that humans will get cancer at the doses people are using; we dont actually know, and that's the point. The development program never got to ask that question.

Sourcing is dominated by gray-market vendors with persistent quality concerns. Research-grade material exists but verification is essential.

Evidence: 50
Mechanism: 80
Reliability: 65
Safety: 25
Sourcing: 45
Value: 50
Signal: 65
Staying power: 35

Plain-language summary Intrigue 60 / 100

Cardarine (GW-501516) is not actually a SARM but is grouped with them by recreational users. It activates PPAR-delta, a nuclear receptor that ramps up fatty acid oxidation and mitochondrial biogenesis in muscle, producing the famous animal data of mice running on treadmills for hours longer than untreated controls. GlaxoSmithKline developed it for high cholesterol and showed favorable HDL and triglyceride effects in phase 2 trials. Development was halted in 2007 after long-term high-dose rodent studies showed cancer in multiple tissues, including liver and bladder. The cancer signal looms over all human use; whether it translates at recreational doses is genuinely unknown. WADA-banned. Not stocked by Kodiac. This monograph is provided for research and educational reference.

Intrigue 0–100 blends mechanism novelty, evidence strength, and translational potential. Kodiac editorial, not peer-reviewed.

PPAR-delta agonist (not a SARM)

A PPAR-delta agonist developed for dyslipidemia; widely used recreationally as an endurance enhancer despite cancer findings in long-term rodent studies.

Abstract

Cardarine (GW-501516, Endurobol; CAS 317318-70-0; molecular formula C21H18F3NO3S2; molecular weight 453.50) is a peroxisome proliferator-activated receptor delta (PPAR-delta) agonist developed at GlaxoSmithKline for dyslipidemia. The compound is not a SARM; it is grouped with SARMs in popular discourse owing to similar recreational use patterns. PPAR-delta activation in skeletal muscle increases fatty acid oxidation, mitochondrial biogenesis, and endurance capacity. Phase 2 trials in dyslipidemia demonstrated favorable lipid profile changes (HDL increase, triglyceride decrease). Development was halted by GSK in 2007 after long-term carcinogenicity studies in rats and mice showed dose-dependent tumor formation in multiple organs at all dose levels tested. The compound retains research utility as the canonical PPAR-delta agonist for academic metabolic research and is widely used recreationally despite the carcinogenicity signal; banned by WADA. Plasma half-life is approximately 24 hours.

Mechanism of action

PPAR-delta agonist; activates fatty acid oxidation, mitochondrial biogenesis, and endurance capacity in skeletal muscle. Not a SARM despite popular grouping.

Reported research dose ranges

Trial doses 2.5 to 10 mg in the published literature; recreational use commonly 10 to 20 mg.

References

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.
Wang YX, et al. Regulation of muscle fiber type and running endurance by PPAR-delta. PLoS Biol 2004.
Geiger LE, et al. Rat carcinogenicity study with GW501516, a PPAR delta agonist. The Toxicologist 2009.

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The full reference document is available as a research-use-only PDF download. Note: PDFs for newly added compounds may take a few hours to propagate after this article was published.

KDC-MN-265

The full reference document is provided strictly for research use only. It reports research dose ranges from the published literature, not instructions for use in humans or animals.

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FOR RESEARCH USE ONLY. Not for medical, diagnostic, or therapeutic purposes. Not for human consumption. All information is provided for research and educational purposes only.

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Cardarine (GW-501516)

Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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Abstract

Mechanism of action

Reported research dose ranges

References

Read the full monograph

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