PPARδ is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-05-08. Numbers and descriptions here follow the published literature rather than marketing material.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
Cardarine is a common name for GW501516, a synthetic compound developed in the 1990s through research collaborations involving GlaxoSmithKline. It belongs to a class of molecules known as peroxisome proliferator-activated receptor delta agonists. Early studies explored its effects on lipid metabolism and energy expenditure in animal models. The compound was never approved as a human medicine, and clinical development was discontinued. In the years since, it has appeared in fitness and bodybuilding communities as a performance-enhancing substance. Regulatory agencies classify it as an unapproved drug.
Detection of GW501516 in biological samples generally relies on liquid chromatography coupled with tandem mass spectrometry. Urine is a common matrix in anti-doping analysis, while blood or plasma may be used in research settings. Sample preparation can involve enzymatic hydrolysis, protein precipitation, or solid-phase extraction before instrumental analysis. Because the compound undergoes metabolism, assays may target the parent molecule, one or more metabolites, or both. Detection windows are not fixed; they depend on factors such as dose, route, individual metabolism, and assay sensitivity. Reference standards are required for accurate identification and quantification.
Handling and quality assessment of cardarine reference material follow general laboratory practices for poorly characterized compounds. It typically appears as a white to off-white powder and is sparingly soluble in water but soluble in organic solvents such as dimethyl sulfoxide and ethanol. Storage recommendations usually specify a cool, dry, dark place, with long-term storage at low temperature and desiccation. Purity may be checked by high-performance liquid chromatography with ultraviolet detection, while identity is confirmed by mass spectrometry and nuclear magnetic resonance. No pharmacopeial monograph exists, so reported purity and stability depend on the supplier’s methods.
GW501516 acts as a selective agonist at PPARδ, a nuclear receptor that regulates transcription of genes involved in lipid handling and energy metabolism. Activation of PPARδ in preclinical models increases fatty acid oxidation, mitochondrial biogenesis, and exercise endurance in rodents. These effects have made the compound a subject of metabolic research and also a target for sport anti-doping rules. In humans, however, controlled studies are limited, and whether similar endurance or metabolic changes occur at tolerated exposures remains an open question. The receptor’s broad tissue distribution also means downstream effects may vary by organ and condition.
| Property | Value | Notes |
|---|---|---|
| CAS Registry Number | 317318-70-0 | Unique identifier for the compound. |
| Chemical class | PPARδ agonist | Synthetic ligand for peroxisome proliferator-activated receptor delta. |
| Appearance | White to off-white solid | Typical form of research-grade material. |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water. |
| Typical storage | -20°C | Recommended for long-term storage of stock solutions. |
Anti-doping laboratories identify GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the usual matrix, and detection can occur after the parent compound has cleared from blood. The exact detection window depends on dose, formulation, individual metabolism, and assay sensitivity. Because the compound is prohibited at all times, athletes are subject to testing in and out of competition. Analytical methods continue to improve as new metabolites and designer analogs are characterized.
GW501516 acts as a ligand for PPAR delta, a nuclear receptor that regulates transcription of genes involved in fatty acid oxidation and energy use. Activation of this receptor in skeletal muscle shifts metabolism toward fat burning in animal models. The compound does not burn fat directly; it changes gene expression over hours to days. Researchers study it to understand metabolic flexibility and exercise adaptation. Effects observed in rodents are not automatically expected in humans.
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.
Cardarine is a common name for GW501516, a synthetic compound first described in the 1990s as a selective agonist of the peroxisome proliferator-activated receptor delta. It was studied in preclinical models for metabolic and cardiovascular conditions, but it has not been approved as a medicine in the United States, Europe, or other major jurisdictions. Retail products labeled as cardarine are generally research chemicals or supplements, not pharmaceutical formulations. Because human safety and efficacy data remain limited, regulatory agencies treat it as an unapproved substance rather than a therapeutic product.
Sporting authorities added GW501516 to prohibited lists after it appeared in athlete samples and online markets. The World Anti-Doping Agency classifies it as a hormone and metabolic modulator, and its use can lead to an anti-doping rule violation. Some early laboratory work suggested effects on fatty acid oxidation and endurance-related metabolism in animals, but those findings do not establish safe or effective use in people. Reports of adverse events in humans are scarce and often anecdotal, which complicates risk assessment.
==== Illegal marketing settlement (2014) ==== In June 2010, health insurance network Blue Cross Blue Shield (BCBS) filed a lawsuit against Pfizer for allegedly illegally marketing drugs Bextra, Geodon and Lyrica. BCBS alleged that Pfizer used kickbacks and wrongly persuaded doctors to prescribe the drugs. According to the lawsuit, Pfizer handed out 'misleading' materials on off-label uses, sent over 5,000 doctors on trips to the Caribbean or around the United States, and paid them $2,000 honoraria in return for listening to lectures about Bextra. Despite Pfizer's claims that "the company's intent was pure" in fostering a legal exchange of information among doctors, an internal marketing plan revealed that Pfizer intended to train physicians "to serve as public relations spokespeople." The case was settled in 2014 for $325 million. Fearing that Pfizer is "too big to fail" and that prosecuting the company would result in disruptions to Medicare and Medicaid, federal prosecutors instead charged a subsidiary of a subsidiary of a subsidiary of Pfizer, which is "nothing more than a shell company whose only function is to plead guilty."
Elsalam asserted she was not aware ractopamine was a prohibited substance, that ractopamine was commonly used overseas to increase meat yields, that she was "a normal Arabic girl", that her family consumed a large quantity of meat during Ramadan (providing a receipt "for the purchase of 20 kilos of Brazilian meat, hot dog and green sausage"), that she was not warned meat could contain prohibited substances, and that further sanctions were "unfair" and "will affect her whole life causing her depression". CAS determined there were two key issues in dispute: Firstly, whether the presence of ractopamine in the athlete's sample constituted a violation of EGY-NADO rules; and secondly, if a violation was committed, the extent to which sanctions should be applied. On the first issue, CAS found "there can be no doubt that Ractopamine is indeed a non-specified substance falling under the category of Other Anabolic Agents" and that no evidence was submitted to suggest otherwise.
A Moscow court ordered the arrests of film producer Alexander Rodnyansky and theatre director Ivan Vyrypaev for "spreading false information" about the Russian army, with Vyrypaev additionally being placed on the Russian federal wanted list by the Interior Ministry. Both individuals had been living in exile for their opposition to the war in Ukraine. Another court sentenced opposition figure and anti-war activist Mikhail Krieger to seven years in prison on charges of justifying terrorism and inciting hatred with the threat of violence prior to the invasion. Prior to his sentencing, Krieger said that he was being prosecuted for his "anti-war and now openly pro-Ukrainian position". During a summit in Iceland, the Council of Europe approved a "Register of Damage" to document actions of Russian forces in Ukraine for future claims of compensation against Russia. The United States, which attended the summit as an observer, Canada and Japan also supported the register.
== Discovery == Identified as a marker of epithelial differentiation upon its discovery in the 1990s, galectin-7 was first characterized for its increased expression in keratinocytes following UVB irradiation. Only later was its dual role in cancers recognized.
Sources: en.wikipedia.org
=== Europe === In Europe, the number of individuals affected by osteoarthritis has increased from 27.9 million in 1990 to 50.8 million in 2019. Hand osteoarthritis was the second most prevalent type, affecting an estimated 12.5 million people. In 2019, knee osteoarthritis was the 18th most common cause of years lived with disability (YLDs) in Europe, accounting for 1.28% of all YLDs. This has increased from 1.12% in 1990.
NAD+ is not approved or licensed for medical use in the UK; there are likely breaches of advertising and medicines rules, and no proof that treatments work. Medical experts say "It's complete nonsense" ... "It's untested and unproven. We don't know anything about its efficacy or long-term safety". A November 2024 study, cited 700 times, claiming that NAD+ levels in lab rats decreased with age was withdrawn after images were found to have been manipulated, and underlying data were not provided to the publishers on request.
== Society and culture == Modafinil's use varies by region. In the US, it is approved for adult narcolepsy, shift work sleep disorder, and obstructive sleep apnea, but not for children. In the UK and the EU, since 2014, it is approved solely for narcolepsy, including in children (pediatric narcolepsy), with its use for other conditions restricted by the European Medicines Agency. Modafinil is not approved for use by children in multiple jurisdictions.
=== 24 March === The RSF launched a series of attacks in eastern Khartoum, killing at least five people and injuring dozens. At the same time, the group retreated from the Salama, Azhari, Ad Hussein, Mayo, Gereif West, Burri, Sahafat and Kalakla neighbourhoods of Khartoum and were seen moving south towards Jebel Aulia. The Darfur Initiative for Justice and Peace said that hundreds of civilians were killed in an SAF airstrike on the Tur'rah market near El Fasher.
Good Clinical Practice Committee Good Laboratory Practice Committee Good Manufacturing Practice Committee Good Pharmacovigilance Practice Committee Animal and Veterinary Product Committee D.I.G.I.T. Committee Medical Devices Committee
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist developed for research. It has not been approved as a medication in any country. It is classified as an unapproved drug and a prohibited substance in sport.
No. Cardarine is not an anabolic steroid; it belongs to a different chemical class that targets PPARδ. Steroids act primarily through androgen receptors, while cardarine acts through a nuclear receptor involved in metabolism.
Some rodent studies reported increased endurance and changes in fat metabolism after cardarine exposure. Long-term studies in animals also raised concerns about cancer in certain tissues. Human trial data are limited, so these findings cannot be directly translated to people.
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.