If you have been reading about GW501516 and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-07-17. Numbers and descriptions here follow the published literature rather than marketing material.
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, an investigational compound developed in the 1990s for metabolic conditions. It acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in lipid and energy metabolism. The compound is frequently mislabeled as a selective androgen receptor modulator, or SARM, but its molecular target is different. GW501516 reached early clinical testing before development was discontinued. It has no approved therapeutic use in any country. The name cardarine is not a formal international nonproprietary name.
Regulatory treatment varies, but cardarine is not approved as a medicine. Sports authorities list GW501516 as a prohibited substance, and it is banned at all times under the World Anti-Doping Agency code. Many countries restrict sales for human consumption, while online vendors market it as a research chemical. Such products may lack purity data, and their actual contents can differ from the label. Purchasing or possessing cardarine may carry legal consequences depending on jurisdiction. The compound is not a dietary supplement ingredient in regulated markets.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic PPARδ agonist | Not a steroid or a selective androgen receptor modulator. |
| Common synonyms | Cardarine, GW501516, GW-501516, endurobol | Names vary by supplier and literature source. |
| Appearance | White to off-white powder | Consistent with many small-molecule research chemicals. |
| Solubility | Low in water; soluble in DMSO and ethanol | Often prepared in organic solvent for laboratory work. |
| Primary target | PPARδ (NR1C2) | Nuclear receptor involved in lipid and energy metabolism. |
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
Literature on cardarine often separates receptor pharmacology from toxicology. Mechanistic papers describe PPARδ activation and gene expression changes, while safety assessments focus on carcinogenicity and species differences. Questions remain about whether rodent tumors arise through PPARδ-dependent or off-target mechanisms. Another open area is how human metabolism and exposure compare with those in animal studies. Analytical methods such as liquid chromatography–mass spectrometry are used to confirm identity in biological and product samples.
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.
Stability of GW501516 depends on form, temperature, light exposure, and moisture. Solid reference material is typically stored frozen or refrigerated in a desiccator and protected from light. Solutions in organic solvents such as dimethyl sulfoxide are often kept frozen in aliquots to reduce freeze-thaw cycling. Aqueous solubility is low, so aqueous stock solutions can be difficult to prepare without cosolvents. Degradation may appear as changes in chromatographic purity or mass spectral signal. Stability studies are needed to establish shelf life for any specific preparation.
In anticipation of the talks, Pakistan military's Inter-Services Intelligence had sent out a private message on WhatsApp to reporters stating that Araghchi was visiting Islamabad and would meet his american counterparts as "Attributable to Government Sources." Araghchi never went to Islamabad to re-open talks and did not be meet with Witkoff and Kushner as was anticipated. Trump had to call off the trip, saying the Iranians could phone them if they wanted. In May, anonymous US officials revealed to CBS News that during the initial ceasefire period in early April, Pakistan covertly allowed Iranian military aircraft, including the RC-130, to park on its airfields, including Nur Khan airbase, potentially shielding them from American airstrikes. Trump administration officials also expressed their suspicions that Pakistan was sharing "a more positive version of the Iranian position with the US than what reflects reality" while questioning whether "Trump’s displeasure" was being communicated as aggressively. On 17 June 2026, the Islamabad Memorandum was signed remotely between the presidents of the US, Donald Trump, and Iran, Masoud Pezeshkian. The memorandum is a 14-point "framework agreement" and provides for an end to military strikes, the reopening of the Strait of Hormuz to commercial shipping toll-free for 60 days, an end to the U.S. naval blockade of Iranian ports, and a 60-day extension of the ceasefire. The memorandum also includes a $300 billion fund for Iran in addition to the release of frozen Iranian assets, as well as sanctions relief.
== History == In 1988, Stark introduced an "Ethics in Patient Referrals" bill concerning physician self-referrals. Some of the ideas in the bill became law as part of the Omnibus Budget Reconciliation Act of 1990. In specific, what is referred to as "Stark I" prohibited a physician referring a Medicare patient to a clinical laboratory if the physician or his/her family member has a financial interest in that laboratory. It was codified in the United States Code, Title 42, Section 1395nn (42 U.S.C. 1395nn, "Limitation on certain physician referrals"). The Omnibus Budget Reconciliation Act of 1993 contained what is known as "Stark II" amendments to the original law. "Stark II" extended the "Stark I" provisions to Medicaid patients and to DHS other than clinical laboratory services. The Centers for Medicare and Medicaid Services has issued rules in the Federal Register to implement Stark Law, including a 2001 "Phase I" final rule, a 2004 "Phase II" interim final rule, and a 2007 "Phase III" final rule.
== Effectiveness == While methadone clinics are generally considered to be effective treatment options for patients addicted to opioids, especially when other interventions have failed, there is controversy surrounding the placement of methadone clinics. There is a perception that the presence of the clinics attracts crime to surrounding areas. However, one study by the University of Maryland School of Medicine found that crime rates do not increase when a methadone clinic is opened. Another study by University of Pennsylvania found within a 200 m radius, the presence of a methadone clinic causes a significant decrease in property and total crime but a significant increase in drug and violent crime. A 2004 GAO study notes that placement of clinics can impede recovery and exacerbate relapse: "Although these clinics are intended to help those in need of rehabilitation, patients who seek treatment must navigate their way to and from the clinics in an environment in which illegal sales of narcotics are daily occurrences. The efforts of patients who are seeking rehabilitation, and clinic professionals who serve them, are significantly undermined by this criminal activity that surrounds them." Between 70 and 90% of patients who discontinue methadone maintenance will relapse. The high relapse rate may be partially due to the severity of cases seen at methadone clinics, as well as the long-term effects of opioid use. Some patients stay on methadone for the rest of their lives, which generates criticism regarding the effectiveness of the clinics.
Sources: en.wikipedia.org
==== Target occupancy studies ==== Studies have estimated occupancy of target sites by trazodone based on trazodone concentrations in blood and brain and on the affinities of trazodone for the human targets in question. Roughly half of brain 5-HT2A receptors are blocked by 1 mg of trazodone and essentially all 5-HT2A receptors are saturated at 10 mg of trazodone, but the clinically effective hypnotic doses of trazodone are in the 25–100 mg range. The occupancy of the serotonin transporter (SERT) by trazodone is estimated to be 86% at 100 mg/day and 90% at 150 mg/day. Trazodone may almost completely occupy the 5-HT2A and 5-HT2C receptors at doses of 100 to 150 mg/day. Significant occupancy of a number of other sites may also occur. However, another study estimated much lower occupancy of the SERT and 5-HT2A receptors by trazodone.
=== Hairpins === A hairpin is a special case of a turn, in which the direction of the protein backbone reverses and the flanking secondary structure elements interact. For example, a beta hairpin connects two hydrogen-bonded, antiparallel β-strands (a rather confusing name, since a β-hairpin may contain many types of turns – α, β, γ, etc.). Beta hairpins may be classified according to the number of residues that make up the turn - that is, that are not part of the flanking β-strands. If this number is X or Y (according to two different definitions of β sheets) the β hairpin is defined as X:Y. Beta turns at the loop ends of beta hairpins have a different distribution of types from the others; type I′ is commonest, followed by types II′, I and II.
In more recent years, some 7-Eleven locations sell 7-Eleven branded fuel without a Big Oil brand, much like 7-Eleven's primary rival Circle K has done in recent years. 7-Eleven signed an agreement with Exxon-Mobil in December 2010 for the acquisition of 183 sites in Florida. This was followed by the acquisition of 51 ExxonMobil sites in North Texas in August 2011. Regardless of fuel brand, 7-Eleven has its own fleet network, 7 Fleet, for business customers and truck drivers at locations large enough to feature dedicated fueling lanes for semi trucks, though 7 Fleet can also be used at standard 7-Eleven locations as well. It is mostly designed to compete with Pilot Flying J's One9 Network designed for owner-operator drivers, as well as drivers that go to standard Pilot Flying J, Love's Travel Stops & Country Stores, and TravelCenters of America locations. On August 2, 2020, Seven & i Holdings announced the buyout of Speedway LLC for $21 billion. The deal closed on May 14, 2021. 7-Eleven was ordered by U.S. antitrust regulators to divest 293 stores across 20 states. 124 stores were sold to Anabi Oil, 106 stores were sold to Cross-America Partners LP and 63 stores were sold to Jacksons Food Stores. 7-Eleven also dropped Speedway's participation in Pilot Flying J's One9 Network in favor of 7 Fleet.
=== For China === As its counterpart as a powerful communist state, the Chinese Communist Party (CCP) has continually placed an emphasis on understanding the Soviet Union and its collapse as lessons for itself. In 2011, the CCP completed a study focusing on four reasons for the Soviet collapse. First, Gorbachev's rapid pursuit of democracy which undermined the centrality of the Communist Party. Second, rapid privatization of state-owned enterprises. Third, the end of the ideological monopoly of the Communist Party, leading to historical nihilism and attacks on socialism. Fourth, the West's promotion of a peaceful evolution, cultivating a pro-West "fifth column" in Soviet society. A 2023 Center for Strategic and International Studies report argued modern Chinese scholarship's attributes the Soviet collapse primarily to its concept of historical nihilism, equated to the penetration of Western ideas into society. In December 1989, then-leader Jiang Zemin first attributed both the fall of communism in Eastern Europe and the Tiananmen Square protests to historical nihilism. A second current in Chinese writing are from Sovietologists who argue the Communist Party of the Soviet Union's institutions and policies was more responsible for collapse than its ideology. Despite Xi Jinping's focus on the historical nihilism current, he stated in 2021 "the Soviet Communist Party separated itself from the people and became a privileged bureaucratic group".
Sources: en.wikipedia.org
== Synthesis, structure, and reactivity == Although fluorene is obtained from coal tar, it can also be prepared by dehydrogenation of diphenylmethane. Alternatively, it can be prepared by the reduction of fluorenone with zinc or hypophosphorous acid–iodine. The fluorene molecule is nearly planar, although each of the two benzene rings is coplanar with the central carbon 9. Fluorene can be found after the incomplete combustion of plastics such as polystyrene, polyethylene and polyvinyl chloride.
Oxazepam is a short-to-intermediate-acting benzodiazepine. Oxazepam is used for the treatment of anxiety, insomnia, and to control symptoms of alcohol withdrawal syndrome. It is a metabolite of diazepam, prazepam, and temazepam, and has moderate amnesic, anxiolytic, anticonvulsant, hypnotic, sedative, and skeletal muscle relaxant properties compared to other benzodiazepines. It was patented in 1962 and approved for medical use in 1964.
Joseph Robinette Biden Jr. was born on November 20, 1942, at St. Mary's Hospital in Scranton, Pennsylvania, to Catherine Eugenia "Jean" Biden (née Finnegan) and Joseph Robinette Biden Sr. He is the oldest child in a Catholic family of predominantly Irish descent. Biden has a sister, Valerie, and two brothers, James and Francis. Joseph Sr. had been wealthy, and the family purchased a home in the affluent Long Island suburb of Garden City, New York, in 1946. After he suffered business setbacks around the time Biden was seven years old, the family lived with Jean's parents in Scranton for several years. Scranton fell into economic decline during the 1950s, and Joseph Sr. could not find steady work. Beginning in 1953, when Biden was ten, the family lived in an apartment in Claymont, Delaware, before moving to a house in nearby Mayfield, Delaware. Joseph Sr. later became a successful used-car salesman, maintaining the family in a middle-class lifestyle. Growing up, Biden observed alcoholism in his family, deciding at a young age to be teetotal. At Archmere Academy in Claymont, Biden played baseball and was a standout halfback and wide receiver on the high school football team. Though a poor student, he was class president in his junior and senior years. He graduated in 1961. At the University of Delaware in Newark, Biden briefly played freshman football and received a Bachelor of Arts degree with a double major in history and political science in 1965. To overcome a childhood stutter, he memorized lines from Ralph Waldo Emerson and William Butler Yeats.
A section of the report pertaining to the internal functioning of the S&D Group was held over until September 2023 to allow for a discussion of its findings with the S&D Bureau prior to its publication.
== Pathophysiology == Episcleritis is caused by inflammation due to the activation of immune cells, including lymphocytes and macrophages. In most cases, the cause of episcleritis is never determined (idiopathic). An identifiable cause is discovered in about one third of cases. Several diseases are associated with episcleritis, including systemic vasculitis (polyarteritis nodosa, granulomatosis with polyangiitis, Behçet's disease), connective tissue diseases (rheumatoid arthritis, relapsing polychondritis, systemic lupus erythematosus), psoriatic arthritis, ankylosing spondylitis, Cogan syndrome, rosacea, gout, atopy, Crohn's disease, and ulcerative colitis. 59 percent of patients with relapsing polychondritis have either episcleritis or scleritis. Rarely, episcleritis may be caused by scleritis. Very rarely, episcleritis is associated with infections, including Lyme disease, tuberculosis, syphilis, and herpes zoster. The redness in the eye associated with episcleritis is due to engorgement of the large episcleral blood vessels, which run in a radial direction from the limbus. Typically, there is no uveitis, or thickening of the sclera.
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist. It is not a steroid or a selective androgen receptor modulator. It was developed and studied as a research compound for metabolic pathways.
It binds to and activates PPARδ, a nuclear receptor that regulates genes related to fatty acid oxidation and energy use. This activation alters transcription in tissues such as skeletal muscle and liver. The full range of downstream effects in humans is not fully established.
No, cardarine is not known to occur naturally in plants, animals, or humans. It is a synthetic molecule produced for laboratory research. Products labeled as cardarine should therefore be treated as manufactured chemicals with variable purity.
No. Cardarine is GW501516, a PPARδ agonist, while SARMs act on androgen receptors. The two classes are often grouped in informal discussions despite different mechanisms.