The short version of PPARδ fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-07-19. Anything still debated is marked as such rather than presented as settled.
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
Cardarine is a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
Quality assessment for cardarine samples usually combines identity, purity, and impurity testing. Nuclear magnetic resonance spectroscopy and mass spectrometry can confirm molecular structure, while high-performance liquid chromatography estimates purity. Certificates of analysis from testing laboratories may list these results, but they do not establish safety or legality. In the absence of approved manufacturing, products sold online may contain the wrong compound, variable amounts, or unlisted contaminants. Independent verification is therefore central to analytical work and to interpreting any reported biological activity.
Laboratory detection of GW501516 commonly uses liquid chromatography coupled with tandem mass spectrometry. The method can identify the parent compound or its metabolites in urine and blood after sample cleanup. Protein precipitation, solid-phase extraction, or enzymatic hydrolysis may precede analysis, depending on the matrix. Reference standards are required for accurate quantification and confirmation. Because the compound is not approved, testing often occurs in anti-doping, forensic, or research settings rather than routine clinical care. Results are reported with limits of detection and quantification.
| Property | Value | Notes |
|---|---|---|
| Common synonyms | GW501516, GW-501516, GW 501516, endurobol | Names vary in research and anti-doping documents. |
| Chemical class | Synthetic PPARδ agonist | Small-molecule nuclear receptor ligand. |
| CAS Registry Number | 317318-70-0 | Identifier commonly associated with GW501516. |
| Appearance | White to off-white powder | Typical for purified research material. |
| Solubility | Low in water; soluble in DMSO and ethanol | Organic solvents are common for laboratory stock solutions. |
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.
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.
Cardarine is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a drug.
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.
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.
=== Seizures === Levetiracetam is an anti-epileptic drug than can be used to treat partial and generalized seizures. Levetiracetam inhibits P/Q channel-mediated glutamate release and decreases the excitatory post synaptic currents of both AMPA and NMDA receptors in the hippocampus, specifically the dentate gyrus, which is known to propagate seizure activities. The inhibition of glutamate release results in an anti-epileptic response in patients because it decreases the excitatory postsynaptic current. There are many different types of calcium channels, so to prove that the P/Q type calcium channels are directly involved, a P/Q type voltage gated calcium channel inhibitor, omega-agatoxin TK, was used to block the channel. When blocked, patients no longer benefited from the anti-epileptic effects from the drugs. When blockers for L type and N type calcium channels were used, the effects of Levetiracetam were still seen. This is strong evidence that the P/Q type calcium channels are involved in the Levetiracetam treatment which allow for relief from seizures.
== Education == Foyer attended Portsmouth Polytechnic (now the University of Portsmouth) from 1971–74, achieving a BSc with Class II, Division I Honours in Biology (CNAA). From 1974–77 she attended the Department of Biochemistry, King's College London, where she completed her PhD. During this time Foyer also attended a course on immunology at Chelsea College, London. In 1998 Foyer was elected a Fellow of the Institute of Biology.
=== Flavoring agents === A large number of pyridine compounds are approved as flavoring agents in the EU. These include the three isomeric picolines and several lutidines. Selected representatives are listed in the following table.
=== Breastfeeding and the prosthetic breast === The breasts of a woman are apocrine glands that produce breastmilk with which to feed an infant child. A woman with implanted prosthetic breasts can breastfeed an infant, yet the breast implants can interfere with the breastfeeding function, especially in the case of a woman whose breast augmentation surgery accidentally cut into the nipple-areola complex (NAC) and might either have damaged the lactiferous ducts or damaged the nerves that serve the nipple-areola complex.
Haemoglobin electrophoresis is a test that can detect different types of haemoglobin. Haemoglobin is extracted from the red cells, then introduced into a porous gel and subjected to an electrical field. This separates normal and abnormal haemoglobin, which can then be identified and quantified. Isoelectric focusing (IEF) is a technique that can be used to diagnose sickle cell disease and other hemoglobinopathies. The technique separates molecules based on their isoelectric point, or the pH at which they have no net electrical charge. IEF uses an electric charge to separate and identify different types of haemoglobin, which become focused into sharp, stationary bands. The technique can distinguish many types of abnormal haemoglobin. High-performance liquid chromatography (HPLC) is reliable, fully automated, and able to distinguish most types of sickle cell disease, including heterozygous. The method separates and quantifies haemoglobin fractions by measuring their flow rate through a column of absorbent material. DNA analysis using polymerase chain reaction (PCR), to amplify small samples of DNA. Variants of PCR used to diagnose sickle cell disease include amplification-refractory mutation system (ARMS) and allele-specific recombinase polymerase amplification. These tests can identify subtypes of sickle cell disease as well as combination hemoglobinopathies.
Sources: en.wikipedia.org
==== Non-state actors ==== United Nations: The UN urged de-escalation between the belligerents and urged measures to protect civilians. European Union: The EU urged de-escalation and the implementation of the ceasefire declared on 15 July. It expressed its concern over Syria's sovereignty and integrity. Arab League: The General Secretariat of the Arab League strongly condemned the Israeli airstrikes on Syria, describing them as a blatant violation of the sovereignty of a fellow Arab League and UN member state and a clear breach of international law. The League characterized the attacks as acts of "bullying" that must not be tolerated by the regional or international community and called for their immediate cessation. It warned that the strikes aimed to sow chaos in Syria by exploiting recent unrest in Suwayda—events which the Syrian government itself denounced and pledged to investigate. The League expressed full solidarity with Syria, urging the government to defuse tensions through dialogue and inclusive national reconciliation. Gulf Cooperation Council: The council condemned Israeli attacks on Syria. The Muslim World League issued a statement expressing its full solidarity with Syria against any threats to its security, stability, and sovereignty, particularly attempts to sow discord among its communities or interfere in its internal affairs. The League voiced support for the Syrian government's efforts to protect all segments of the population, uphold civil peace, and enforce the rule of law.
== Top CROs by annual revenue == As of 2016, there was a 15.5% increase in R&D spending from 2015 to 2020. The list of contract research organizations includes the following notable companies worldwide:
=== Phase 3 === Gepirone (Ariza; BMY-13805; Exxua; Gepirone ER; MJ-13805; Org-33062; TGFK-07AD; TGFK07AD; Travivo; Variza) – serotonin 5-HT1A receptor partial agonist [1] Lysergic acid diethylamide (LSD; lysergide; MM-120; MM120) – non-selective serotonin receptor agonist and psychedelic hallucinogen [2] [3] Toludesvenlafaxine extended release (4-methylbenzoate desvenlafaxine; ansofaxine; desvenlafaxine prodrug; LPM-570065; LY-03005; Ruoxinlin) – serotonin–norepinephrine–dopamine reuptake inhibitor (SNDRI) [4] Vilazodone (EMD-68843; SB-659746A; Viibryd) – serotonin reuptake inhibitor (SRI) and serotonin 5-HT1A receptor partial agonist [5]
== Discovery and ownership background == On 1 November 2005, Cambridge Antibody Technology (CAT) announced it was acquiring two anti-CD22 immunotoxin products from Genencor, namely GCR-3888 and GCR-8015. Genencor is the biotechnology division of Danisco and the acquisition meant CAT would hire certain former Genencor key employees to be responsible for the development of the programmes. GCR-3888 and GCR-8015 were discovered and initially developed by the National Cancer Institute, which is part of the U.S. National Institutes of Health. Genencor licensed the candidates for hematological malignancies and entered into a Cooperative Research and Development Agreement (CRADA) with the NIH, which will now be continued by CAT. Under the original license agreement with the NIH, CAT gained the rights to a portfolio of intellectual property associated with the programs and would pay future royalties to the NIH. CAT intended to file an Investigational New Drug (IND) application for GCR-8015 in various CD22 positive B-cell malignancies, including Non-Hodgkin lymphoma and chronic lymphocytic leukemia, following a period of manufacturing development which is expected to be complete by the end of 2006 and to support the NCI's ongoing development of GCR-3888 in Hairy cell leukemia (HCL) and pediatric acute lymphoblastic leukemia (pALL). CAT-8015 exhibited a greater affinity for CD22 than its predecessor, CAT-3888 and CAT's language such as "CAT will support the NCI's ongoing development of CAT-3888..." suggested at the time that their focus was on the second generation candidate.
Sources: en.wikipedia.org
Cardarine is an investigational synthetic compound that acts as a PPARδ agonist. It is also known as GW501516 and has been studied mainly in preclinical research. It is not an approved medicine.
No. Cardarine is not a steroid hormone; it targets the nuclear receptor PPARδ. Its classification in anti-doping rules differs from anabolic steroids, though it remains prohibited in sport.
Early rodent studies reported tumor formation at multiple sites, which raised safety concerns. Sponsors stopped clinical development, and no approved human product exists.
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.