A practical reference on GW501516: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-09-02. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| 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. |
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.
The pharmacological interest in cardarine centers on PPARδ activation and its downstream effects on lipid handling and mitochondrial function. In animal studies, PPARδ agonists have been associated with changes in exercise endurance and fatty acid utilization, though results vary by model and protocol. Human data remain sparse, and the absence of large controlled trials limits conclusions about efficacy. Researchers often describe the compound as a tool for probing PPARδ biology rather than a proven therapeutic agent.
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.
Published literature on cardarine includes in vitro assays, rodent experiments, and a small number of human studies. Reports describe effects on exercise capacity and lipid metabolism in animals, while human evidence is sparse. Many online descriptions present the compound as a proven endurance aid, a claim not supported by regulatory approval or large clinical trials. Analytical studies focus on identifying the parent compound and its metabolites in biological samples. Important uncertainties include species differences, dose-response relationships, and the relevance of rodent tumor findings to humans.
Cardarine is the common name for GW501516, a synthetic compound studied as a peroxisome proliferator-activated receptor delta agonist. Researchers developed it to explore treatments for lipid disorders and metabolic conditions. It is not an approved medicine in any country. Early clinical work examined changes in HDL cholesterol and triglycerides, but development was discontinued after animal studies raised concerns about cancer. The compound remains available as a research chemical and appears in discussions of performance enhancement.
== Prognosis == The availability of treatments that modify the course of multiple sclerosis beginning in the 1990s, known as disease-modifying therapies (DMTs), has improved prognosis. These treatments can reduce relapses and slow progression, but there is no cure. Before the advent of these medications, it took around 15 years before relapsing-remitting MS progressed to secondary progressive MS (which has associated mobility issues). With these medications, the progression is slower to 40 years. The prognosis of MS depends on the subtype of the disease, and there is considerable individual variation in the progression of the disease. In relapsing MS, the most common subtype, a 2016 cohort study found that after a median of 16.8 years from onset, one in ten needed a walking aid, and almost two in ten transitioned to secondary progressive MS, a form characterized by more progressive decline. With treatments available in the 2020s, relapses can be eliminated or substantially reduced. However, "silent progression" of the disease still occurs. In addition to secondary progressive MS (SPMS), a small proportion of people with MS (10–15%) experience progressive decline from the onset, known as primary progressive MS (PPMS). Most treatments have been approved for use in relapsing MS; there are fewer treatments with lower efficacy for progressive forms of MS. The prognosis for progressive MS is worse, with faster accumulation of disability, though with considerable individual variation.
All organisms are constantly exposed to compounds that they cannot use as foods and that would be harmful if they accumulated in cells, as they have no metabolic function. These potentially damaging compounds are called xenobiotics. Xenobiotics such as synthetic drugs, natural poisons and antibiotics are detoxified by a set of xenobiotic-metabolizing enzymes. In humans, these include cytochrome P450 oxidases, UDP-glucuronosyltransferases, and glutathione S-transferases. This system of enzymes acts in three stages to firstly oxidize the xenobiotic (phase I) and then conjugate water-soluble groups onto the molecule (phase II). The modified water-soluble xenobiotic can then be pumped out of cells and in multicellular organisms may be further metabolized before being excreted (phase III). In ecology, these reactions are particularly important in microbial biodegradation of pollutants and the bioremediation of contaminated land and oil spills. Many of these microbial reactions are shared with multicellular organisms, but due to the incredible diversity of types of microbes these organisms are able to deal with a far wider range of xenobiotics than multicellular organisms, and can degrade even persistent organic pollutants such as organochlorines compounds. A related problem for aerobic organisms is oxidative stress. Here, processes including oxidative phosphorylation and the formation of disulfide bonds during protein folding produce reactive oxygen species such as hydrogen peroxide.
Common barbiturate side effects include nausea, hypotension, headache, drowsiness, and skin rash. More serious side effects can include confusion, slow breathing, hallucination, fainting, and coma. Rare side effects may include agranulocytosis, liver injury, megaloblastic anemia, or Stevens-Johnson Syndrome.
It was shown that short-term metreleptin treatment of patients with anorexia nervosa had rapid on-set of beneficial cognitive, emotional, and behavioral effects. Among other things, depression, drive for activity, repetitive thoughts of food, inner restlessness, and weight phobia decreased rapidly. Whether metreleptin (or another leptin analogue) is a suitable treatment for anorexia nervosa remains to be seen. Potential side effects are weight loss and the development of anti-metreleptin antibodies. In a clinical study, metreleptin treatment improved non-alcoholic steatohepatitis (fatty liver disease) both in patients with partial lipodystrophy and in those with relative leptin deficiency. Both steatosis and hepatic injury scores decreased. Metreleptin reduces body weight in overweight people with low leptin levels. Although it is not very effective as a weight loss drug, leptin levels are lowered in people who have lost weight and it is hypothesized that supplemental leptin could help them with weight loss maintenance. However, there is no regulatory pathway for drug approval for this indication.
== Definition == The chirality of a molecule is based on the molecular symmetry of its conformations. A conformation of a molecule is chiral if and only if it belongs to the Cn, Dn, T, O, or I point groups (the chiral point groups). However, whether the molecule itself is considered to be chiral depends on whether its chiral conformations are persistent isomers that could be isolated as separated enantiomers, at least in principle, or the enantiomeric conformers rapidly interconvert at a given temperature and timescale through low-energy conformational changes (rendering the molecule achiral). For example, despite having chiral gauche conformers that belong to the C2 point group, butane is considered achiral at room temperature because rotation about the central C–C bond rapidly interconverts the enantiomers (3.4 kcal/mol barrier). Similarly, cis-1,2-dichlorocyclohexane consists of chair conformers that are nonidentical mirror images, but the two can interconvert via the cyclohexane chair flip (~10 kcal/mol barrier). As another example, amines with three distinct substituents (R1R2R3N:) are also regarded as achiral molecules because their enantiomeric pyramidal conformers rapidly undergo pyramidal inversion. However, if the temperature in question is low enough, the process that interconverts the enantiomeric chiral conformations becomes slow compared to a given timescale. The molecule would then be considered to be chiral at that temperature.
Sources: en.wikipedia.org
It was never resolved. By the close of the 1960s, the US and the UK had turbofans with bypass ratios of 4 or 5 to 1. The first Soviet large turbofan, the Lotarev D-18T, did not appear before the mid-1980s. The Soloviev D-30, originally intended for the Il-86, was the most advanced Soviet civil aeroengine. It had a bypass ratio of 2.4 to 1 and aerodynamic clamshell thrust reversers. It failed to attain the required thrust, however: "only after the lapse of three years that were spent on preparing the advanced development project did it become clear that these engines would not provide the necessary take-off performance." The less-advanced Kuznetsov NK-8 series engine, adopted on March 26, 1975, had a bypass ratio of 1.15 to 1 and drag-inducing grilles over its cascade thrust reversers. Both these engines had high specific fuel consumptions and were noisy. Being ultimate developments of smaller engines, they could not offer growth to future Il-86s. The appropriate/intermediate technology principles to which most Soviet airliners before the Il-86 had been designed meant that they had typically five-member flight crews. The design and entry into service in 1972 of the Tu-154, an airliner built to high technology principles (more automation, less human input), showed that Soviet science lagged behind in the development of avionics which would remove the need for navigators and radio operators. A programme of avionics development was mounted to enable the Il-86 to operate in most weather with a three-member flight crew, matching Western technology of the time.
=== 1980s === 1982: Nephrologist Leah Lowenstein became the first woman dean of a co-educational medical school in the United States. 1983: Barbara McClintock received the Nobel Prize in Physiology or Medicine for her discovery of genetic transposition; she was the first woman to receive that prize without sharing it, and the first American woman to receive any unshared Nobel Prize. 1984: Kathryn D. Sullivan becomes the first American woman to walk in space. 1988: Patricia Bath was the first African American woman to receive a medical patent, which was her invention of laser cataract treatment. 1988: Gertrude B. Elion received the Nobel Prize in Physiology or Medicine along with James W. Black and George H. Hitchings "for their discoveries of important principles for drug treatment".
The European Journal of Mass Spectrometry is a peer-reviewed scientific journal covering all areas of mass spectrometry. It is published by SAGE Publishing and the editor-in-chief is Jürgen Grotemeyer (Kiel University).
=== Leak === On September 19, the Half-Life 2 source code was obtained by a German hacker, Axel Gembe, who had infiltrated Valve's internal network months earlier. According to Gembe, he shared it with another person, who leaked the code online in early October. Fans soon compiled a playable version of Half-Life 2, revealing how unfinished it was. The leaks damaged morale at Valve and slowed development. Fans also provided Valve with the details of people involved in the leaks. In March 2004, Gembe contacted Newell, saying he was a fan and had not acted maliciously. Newell worked with the FBI to invite Gembe to a fake job interview, planning to have him arrested in the United States; however, police arrested him in Germany. In November 2006, Gembe was sentenced to two years' probation. Valve implemented new policies to protect against leaks, such as requiring journalists to attend their office to play it before release.
The neuroendocrine system is an integrated system composed of neurons, glands and non-endocrine tissues, and the hormones and neurochemicals they produce and receive collectively regulate physiological or behavioral state.
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.
Anti-doping and clinical laboratories commonly use liquid chromatography-tandem mass spectrometry. The method can identify GW501516 and its metabolites in urine or blood. Detection depends on sample timing and the amount present.