A practical reference on Cardarine: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-05-18 and is reviewed periodically as new material appears.
Laboratory studies indicate that GW501516 activates PPARδ, a nuclear receptor involved in fatty acid oxidation and energy metabolism. In rodent experiments, treated animals often showed increased endurance and reduced fat mass. These effects were observed under controlled conditions and do not establish safe or effective use in humans. The exact dose-response relationship in humans remains poorly characterized. Species differences in metabolism can affect how results translate across animals and people.
Safety concerns emerged from long-term animal studies. In rodents given the compound for extended periods, researchers found an increased incidence of certain cancers, including liver and bladder tumors. These findings contributed to the discontinuation of clinical development. Whether similar risks apply to short-term or low-level exposure in humans is not established, and controlled human safety data are limited. The relevance of high-dose rodent carcinogenicity findings to human use remains a subject of debate.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
| Property | Value | Notes |
|---|---|---|
| Primary target | PPARδ (NR1C2) | Nuclear receptor involved in lipid metabolism |
| Preclinical effect | Increased fatty acid oxidation | Observed in rodent studies |
| Key safety signal | Tumors in rodents after long-term exposure | Contributed to halted clinical development |
| Human trial status | No approved product; development stopped | Limited short-term metabolic data |
| Sport regulatory status | Prohibited at all times | WADA hormone and metabolic modulators class |
Cardarine is a common name for GW501516, a synthetic compound studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
Published human data are sparse and mostly come from early-phase trials. Those studies examined short-term changes in lipids, glucose, and exercise capacity, but they were not large enough to establish efficacy or long-term safety. Some animal experiments reported increased running endurance, yet such findings do not prove a performance benefit in people. Anti-doping laboratories detect GW501516 and its metabolites in urine or blood using liquid chromatography-tandem mass spectrometry. Detection windows depend on dose, sample type, and individual metabolism. The method is sensitive enough to identify trace residues in tested samples.
Laboratory handling focuses on identity, purity, and stability. Reference standards are typically stored cold and dry, protected from light, because solutions can degrade over time. Analytical checks may use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Impurities and related substances can be separated chromatographically and compared with a known standard. Because cardarine is not an approved drug, compendial monographs are absent, and laboratories often rely on in-house methods. Reported purity varies among unregulated products and should not be assumed from a label.
GW501516 binds and activates PPARδ, a nuclear receptor that influences transcription of genes involved in fatty acid oxidation and energy use. Activation shifts some metabolic pathways in preclinical models, which is why the compound has been studied for lipid disorders and exercise-related endpoints. The exact downstream effects in humans are incompletely mapped. PPARδ is expressed in many tissues, including skeletal muscle, liver, and adipose tissue, so broad activation may have varied consequences. Researchers continue to examine how selective or partial activation might alter the balance between benefits and risks.
== Lexicology == The Latin term impotentia coeundi describes simple inability to insert the penis into the vagina; it is now mostly replaced by more precise terms, such as erectile dysfunction (ED). The study of ED within medicine is covered by andrology, a sub-field within urology. Research indicates that ED is common, and it is suggested that approximately 40% of males experience symptoms compatible with ED, at least occasionally. The condition is also on occasion called phallic impotence. Its antonym, or opposite condition, is priapism.
== Reception of Kermani's work == Gustav Seibt of the newspaper Süddeutsche Zeitung highlights Kermani's demonstrated ability to converse effortlessly with the positions of Herder, Goethe, Rückert and the Orientalism of German Classicism, and to comment just as competently on Lessing, Kleist, Hölderlin and Kafka as on the aesthetics of the Koran and Islamic mysticism. Kermani's book on Canadian rock musician Neil Young, Das Buch der von Neil Young Getöteten [The Book of Those Killed by Neil Young, 2002], has been reviewed numerous times, having been a great success with critics and audiences alike. At the end of 2023, publishing house Suhrkamp released this book in its tenth edition. The Neil Young book has been adapted for the stage several times, including at the Thalia Theater in Hamburg. In addition, a radio station was named for the book. Since 2010, this radio station has been presenting music online that Neil Young would like or that people who also like Neil Young would like. In November 2005, Kermani staged Hosea at the Schauspiel Köln theater, a play based on biblical texts and on works by Friedrich Hebbel. Kermani's book Der Schrecken Gottes – Attar, Hiob und die metaphysische Revolte (The Terror of God – Attar, Job, and the Metaphysical Revolt) published in 2005, was described by Uwe Justus Wenzel of the Swiss newspaper Neue Zürcher Zeitung as "healthily disturbing" and by Karl-Josef Kuschel of the Frankfurter Rundschau as "literally boundary-breaking".
Decreases in laboratory reimbursement have led to a decline in the number of NAACLS accredited MLS programs from ~700 in 1975 to ~240 programs in 2002, where it has held since. NAACLS program graduates are eligible to sit for American Society for Clinical Pathology(ASCP) certifications.
High efficiency and throughput Increased simplicity and speed The reaction can be driven to completion and high yields through the use of excess reagent. In this method, building blocks are protected at all reactive functional groups. The order of functional group reactions can be controlled by the order of deprotection. This method is used for the synthesis of peptides, deoxyribonucleic acid (DNA), ribonucleic acid (RNA), and other molecules that need to be synthesised in a certain alignment. More recently, this method has also been used in combinatorial chemistry and other synthetic applications. The process was originally developed in the 1950s and 1960s by Robert Bruce Merrifield in order to synthesise peptide chains, and which was the basis for his 1984 Nobel Prize in Chemistry. In the basic method of solid-phase synthesis, building blocks that have two functional groups are used. One of the functional groups of the building block is usually protected by a protective group. The starting material is a bead which binds to the building block. At first, this bead is added into the solution of the protected building block and stirred. After the reaction between the bead and the protected building block is completed, the solution is removed and the bead is washed. Then the protecting group is removed and the above steps are repeated. After all steps are finished, the synthesised compound is chemically cleaved from the bead.
Sources: en.wikipedia.org
== Regulation == In keeping with its critical importance in maintaining life, GCL is subject to a multi-level regulation of its expression, function, and activity. GCL expression is regulated at the transcriptional (transcription of the GCLC and GCLM DNA to make mRNA), posttranscriptional (the stability of the mRNA over time), translational (processing of the mRNA into protein), and posttranslational levels (involving modifications to the existing proteins). Although baseline constitutive expression is required to maintain cell viability, expression of the GCL subunits is also inducible in response to oxidative stress, GSH depletion, and exposure to toxic chemicals, with the Nrf2, AP-1, and NF-κB transcription factors regulating the inducible and constitutive expression of both subunits In terms of enzyme functional regulation, GSH itself acts as a feedback inhibitor of GCL activity. Under normal physiologic substrate concentrations, the GCLC monomer alone may synthesize gamma-glutamylcysteine; however, the normal physiologic levels of GSH (estimated at around 5 mM) far exceeds the GSH Ki for GCLC, suggesting that only the GCL holoenzyme is functional under baseline conditions. However, during oxidative stress or toxic insults that can result in the depletion of cellular GSH or its oxidation to glutathione disulfide (GSSG), the function of any monomeric GCLC in the cell is likely to become quite important.
== External links == Erowid on GBL "The paint stripper drug that kills". BBC News. October 7, 2005. "All About GHB," a NIDA Neuroscience Consortium and OSPC "Cutting Edge" colloquium (27 June 2000 at the Doubletree hotel, Rockville, MD)
=== REDEFINE 5 === In April 2026, results were published in The Lancet on REDEFINE 5, a 68-week, double-blind, phase 3a clinical trial enrolling 331 participants. The study findings report that participants in the CagriSema cohort had an estimated mean bodyweight change of -18.4%, versus -11.7% for participants in the semaglutide cohort.
Sources: en.wikipedia.org
Rodent studies reported increased endurance and fat oxidation after GW501516 exposure. Long-term studies also found higher rates of some tumors, which led to halted development.
Small short-term human trials examined metabolic markers such as lipids and glucose. The trials did not continue after rodent cancer findings, so long-term human safety is unknown.
Controlled human trials have not established a performance benefit. Anecdotal reports exist, but they are not reliable evidence.
Cardarine is commonly known as GW501516 or GW-1516. These names refer to the same synthetic compound. It is not a brand-name approved medicine.