This is a working overview of GW501516, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-01-10. Anything still debated is marked as such rather than presented as settled.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white solid | Typical form of reference material |
| Solubility | Low in water; soluble in DMSO | Used to prepare stock solutions |
| Typical storage | -20 °C, desiccated, protected from light | Common laboratory practice |
| Analytical method | LC-MS/MS | Detects parent compound and metabolites |
| Common test matrix | Urine or blood | Used in anti-doping analysis |
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.
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.
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.
At the molecular level, GW501516 binds and activates PPARδ, a nuclear receptor that regulates transcription. Activation shifts expression of genes involved in fatty acid oxidation, energy expenditure, and lipid transport in skeletal muscle and liver. Animal studies report increased endurance and altered lipid profiles after exposure. Human data are limited to small trials and do not establish long-term safety or efficacy. PPARδ also has roles in cell proliferation, so the relationship between activation and cancer risk remains an open question.
=== Mechanism of action === Clindamycin phosphate is a water-soluble ester of the semi-synthetic antibiotic clindamycin, which is synthesized from lincomycin. Like the macrolide antibiotics, it acts as a bacteriostatic agent by interfering with the 50S subunit of the ribosome of Cutibacterium acnes, inhibiting bacterial protein synthesis and preventing bacteria from replicating. C. acnes plays a role in the development of acne. Benzoyl peroxide also kills C. acnes, but by releasing free radical oxygen species, thus oxidizing bacterial proteins. Also, it dries out the area by reducing sebum production, prevents clogged pores, and is a keratolytic agent. Since benzoyl peroxide is an oxidizer, not an antibiotic, it is not subject to C. acnes resistance unlike clindamycin. Both ingredients have been shown to reduce the number of acne lesions with statistical significance.
The journey across the United States began on 15 July 1988. On the journey he slept in bushes beneath the World Trade Center, camped outside Kennedy Airport in a tent, then headed west. On Staten Island he collapsed from heat exhaustion at 105 degrees Fahrenheit. In Utah the temperatures went down to minus 30 Fahrenheit. Carrying a tent and a backpack, with no backup, he walked alone to Niagara Falls, through Ontario in Canada, to Detroit, between the Great Lakes, across the Great Plains, through the Rockies in winter, to Yellowstone National Park, then south to the Grand Canyon, on to Las Vegas, through Death Valley and then snowshoed over the Sierras to reach San Francisco. In Death Valley, down to his last $13, Skinner found $200 in the desert, and he had $1 left when he crossed the Sierras to reach Yosemite Valley. The total distance he walked from New York City to San Francisco, was 4,952 miles (7,969 km). On the journey he visited 70 hospices and appeared on television, radio and in newspapers to encourage support for hospices across the U.S. and Canada. The mayor of San Francisco, Art Agnos, proclaimed 21 March 1989, "Colin Skinner Day," in recognition of the attention he brought to the work of hospices with AIDS patients in the city. Returning to Britain after this walk, he obtained a job as a research assistant in Chemical Pathology at the Middlesex Hospital and went on to obtain a PhD in Molecular Biology at University College London.
These transformations set the stage for the introduction of both epoxide groups, which were formed with high levels of diastereoselectivity based on the principles of macrocyclic stereocontrol. The first epoxide was introduced via nucleophilic epoxidation of the enone using potassium hydride and tert-butylhydroperoxide; this led to the formation of a 4:1 mixture of diastereomeric epoxides, favoring the desired isomer in which attack had occurred from the peripheral face of the enone. At this stage, the ketone was transformed into the second epoxide group using the Johnson-Corey-Chaykovsky reaction; notably, the product was formed as a single diastereomer, again due to initial peripheral attack of the dimethylsulfonium methylide nucleophile on the ketone. Subsequent removal of the TBS protecting group and Sarett oxidation of the resulting secondary alcohol completed the total synthesis of racemic periplanone B.
Sources: en.wikipedia.org
Solid supports for peptide synthesis are selected for physical stability, to permit the rapid filtration of liquids. Suitable supports are inert to reagents and solvents used during SPPS and allow for the attachment of the first amino acid. Swelling is of great importance because peptide synthesis takes place within the solvent-swollen resin beads. The primary type of solid supports is suspension polymerized copoly(1% m-divinyl + styrene)beaded resin. Improvements to solid supports used for peptide synthesis enhance their ability to withstand the repeated use of TFA during the deprotection step of SPPS. Two primary resins are used, based on whether a C-terminal carboxylic acid or amide is desired. The Wang resin was, as of 1996, the most commonly used resin for peptides with C-terminal carboxylic acids.
Selective serotonin reuptake inhibitors (SSRIs) are a class of drugs that are typically used as antidepressants in the treatment of major depressive disorder, anxiety disorders, and other psychiatric conditions. SSRIs primarily work by blocking serotonin reabsorption (reuptake) via the serotonin transporter, leading to gradual changes in brain signaling and receptor regulation, with some also interacting with sigma-1 receptors, particularly fluvoxamine, which may contribute to cognitive effects. Marketed SSRIs include six main antidepressants—citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline—and dapoxetine, which is indicated for premature ejaculation. Fluoxetine has been approved for veterinary use in the treatment of canine separation anxiety. SSRIs are the most widely prescribed antidepressants in many countries. In adults, they are recommended as a first-line treatment for moderate to severe depression, while for mild depression non-drug treatments are preferred unless the patient chooses medication. A 2018 meta analysis of 21 antidepressants showed that all antidepressants (including SSRIs) were more effective than placebo in adults with major depressive disorder.
Of the 66 cases of measles reported in the US in 2005, slightly over half were attributable to one unvaccinated individual who acquired measles during a visit to Romania. This individual returned to a community with many unvaccinated children. The resulting outbreak infected 34 people, mostly children and virtually all unvaccinated; 9% were hospitalized, and the cost of containing the outbreak was estimated at $167,685. A major epidemic was averted due to high rates of vaccination in the surrounding communities. In 2017, an outbreak of measles occurred among the Somali-American community in Minnesota, where MMR vaccination rates had declined due to the misconception that the vaccine could cause autism. The US Centers for Disease Control and Prevention recorded 65 affected children in the outbreak by April 2017.
Sources: en.wikipedia.org
"p53 Knowledgebase". Lane Group at the Institute of Molecular and Cell Biology (IMCB), Singapore. Archived from the original on 2006-01-03. Retrieved 2008-04-06. GeneReviews/NCBI/NIH/UW entry on Li-Fraumeni Syndrome TUMOR PROTEIN p53 @ OMIM p53 restoration of function p53 @ The Atlas of Genetics and Cytogenetics in Oncology and Haematology TP53 Gene @ GeneCards p53 News provided by insciences organisation Goodsel DS (2002-07-01). "p53 Tumor Suppressor". Molecule of the Month. RCSB Protein Data Bank. Retrieved 2008-04-06. Soussi T. "p53 Web Site". Retrieved 2008-04-06. Living LFS A non-profit Li-Fraumeni Syndrome patient support organization The George Pantziarka TP53 Trust A support group from the UK for people with Li-Fraumeni Syndrome or other TP53-related disorders IARC TP53 Somatic Mutations database maintained at IARC, Lyon, by Magali Olivier PDBe-KB provides an overview of all the structure information available in the PDB for Human P53. scientific animation conformational changes of p53 upon binding to DNA
== Education == Shulman earned a Bachelor of Science degree in biophysics from the University of Michigan in 1974, graduating with high honors and distinction. He received both his M.D. and Ph.D. in physiology from Wayne State University in 1979. From 1979 to 1981, he completed his internship and residency training in internal medicine at Duke University Medical Center. He then completed his clinical and research fellowship in endocrinology and metabolism at Massachusetts General Hospital/Harvard Medical School from 1981 to 1984.
Anticoagulants and anti-platelet agents (together "antithrombotics") are amongst the most commonly used medications. Anti-platelet agents include aspirin, dipyridamole, ticlopidine, clopidogrel, ticagrelor and prasugrel; the parenteral glycoprotein IIb/IIIa inhibitors are used during angioplasty. Of the anticoagulants, warfarin (and related coumarins) and heparin are the most commonly used. Warfarin affects the vitamin K-dependent clotting factors (II, VII, IX, X) and protein C and protein S, whereas heparin and related compounds increase the action of antithrombin on thrombin and factor Xa. A newer class of drugs, the direct thrombin inhibitors, is under development; some members are already in clinical use (such as lepirudin, argatroban, bivalirudin and dabigatran). Also in clinical use are other small molecular compounds that interfere directly with the enzymatic action of particular coagulation factors (the directly acting oral anticoagulants: dabigatran, rivaroxaban, apixaban, and edoxaban).
Sources: en.wikipedia.org
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.
PPARδ is a nuclear receptor that regulates genes linked to fatty acid oxidation and energy metabolism. Activation can alter lipid handling and energy use in experimental models. The full range of effects in humans is still under study.
The solid compound is generally stable when kept cold, dry, and protected from light. Solutions may degrade faster, so laboratory protocols often specify fresh preparation or cold storage. Stability can depend on solvent, concentration, and container.
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.