LC-MS/MS 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 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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 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.
PPARδ is a nuclear receptor that regulates gene expression related to fatty acid oxidation, glucose homeostasis, and mitochondrial function. GW501516 binds to this receptor with high affinity and activates downstream signaling in skeletal muscle and other tissues. Animal studies reported increased endurance and altered fuel preference, but human data remain limited and inconsistent. The precise relationship between receptor activation and observed physiological changes is still an area of active investigation. Researchers have also examined whether the compound affects inflammation or cell proliferation. No approved therapeutic indication exists for cardarine.
| 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. |
Cardarine is a common name for the investigational chemical GW501516, also written GW-1516. It was developed as a peroxisome proliferator-activated receptor delta agonist for metabolic conditions such as dyslipidemia. Early research focused on lipid handling and energy use in skeletal muscle and other tissues. The compound was never approved as a medicine. In public discussion, it is often grouped with performance-enhancing substances, although its receptor target differs from that of anabolic steroids or selective androgen receptor modulators. Regulatory and health authorities have issued warnings about its use.
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.
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.
Products sold as cardarine have been found to contain incorrect compounds, variable amounts, or no active ingredient at all. Independent testing is required to verify identity and purity. Common analytical approaches include high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance for structural confirmation. These methods can distinguish GW501516 from related PPAR agonists and from unrelated steroids. For regulators and researchers, such verification is central to interpreting both biological results and adverse event reports.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
Anti-doping laboratories detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
Exometabolomics, also known as 'metabolic footprinting', is the study of extracellular metabolites and is a sub-field of metabolomics. While the same analytical approaches used for profiling metabolites apply to exometabolomics, including liquid-chromatography mass spectrometry (LC-MS), nuclear magnetic resonance (NMR) and gas chromatography–mass spectrometry (GC–MS), analysis of exometabolites provides specific challenges and is most commonly focused on investigation of the transformations of exogenous metabolite pools by biological systems. Typically, these experiments are performed by comparing metabolites at two or more time points, for example, spent vs. uninoculated/control culture media; this approach can differentiate different physiological states of wild-type yeast and between yeast mutants. Since, in many cases, the exometabolite (extracellular) pool is less dynamic than endometabolite (intracellular) pools (which are often perturbed during sample processing) and chemically defined media can be used, it reduces some of the experimental challenges of metabolomics. Exometabolomics is also used as a complementary tool with genomic, transcriptomic and proteomic data, to gain insight into the function of genes and pathways. Additionally, exometabolomics can be used to measure polar molecules being consumed or released by an organism, and to measure secondary metabolite production.
== External links == Syria at Human Rights Watch Syria Charter of Rights and Freedoms Is a proposed modern system of human rights for adoption prior to a new Syrian constitution. 2010 Human Rights Report: Syria, U.S. Department of State, 8 April 2011 "Syria rights activist jailed for five years". Middle East Online. April 24, 2007. Archived from the original on September 28, 2007. Retrieved April 26, 2007. Uprising against the Assad Regime in Syria: Is This a Second Libya? June 2011, Qantara.de Worrall, James; Hightower, Victoria Penziner (2021). "Methods in the madness? Exploring the logics of torture in Syrian counterinsurgency practices". British Journal of Middle Eastern Studies. 49 (3): 418–432. doi:10.1080/13530194.2021.1916154. S2CID 234872905.
=== Complications === A number of complications may occur, with infections being the most common. In order of frequency, potential complications include: pneumonia, cellulitis, urinary tract infections and respiratory failure. Risk factors for infection include: burns of more than 30% TBSA, full-thickness burns, extremes of age (young or old), or burns involving the legs or perineum. Pneumonia occurs particularly commonly in those with inhalation injuries. Anemia secondary to full thickness burns of greater than 10% TBSA is common. Electrical burns may lead to compartment syndrome or rhabdomyolysis due to muscle breakdown. Blood clotting in the veins of the legs is estimated to occur in 6 to 25% of people. The hypermetabolic state that may persist for years after a major burn can result in a decrease in bone density and a loss of muscle mass. Keloids may form subsequent to a burn, particularly in those who are young and dark skinned. Following a burn, children may have significant psychological trauma and experience post-traumatic stress disorder. Scarring may also result in a disturbance in body image. To treat hypertrophic scars (raised, tense, stiff and itchy scars) and limit their effect on physical function and everyday activities, silicone sheeting and compression garments are recommended. In the developing world, significant burns may result in social isolation, extreme poverty and child abandonment.
Sources: en.wikipedia.org
=== Cancer === Inflammation orchestrates the microenvironment around tumours, contributing to proliferation, survival and migration. Cancer cells use selectins, chemokines and their receptors for invasion, migration and metastasis. On the other hand, many cells of the immune system contribute to cancer immunology, suppressing cancer. Molecular intersection between receptors of steroid hormones, which have important effects on cellular development, and transcription factors that play key roles in inflammation, such as NF-κB, may mediate some of the most critical effects of inflammatory stimuli on cancer cells. This capacity of a mediator of inflammation to influence the effects of steroid hormones in cells is very likely to affect carcinogenesis. On the other hand, due to the modular nature of many steroid hormone receptors, this interaction may offer ways to interfere with cancer progression, through targeting of a specific protein domain in a specific cell type. Such an approach may limit side effects that are unrelated to the tumor of interest, and may help preserve vital homeostatic functions and developmental processes in the organism. There is some evidence from 2009 to suggest that cancer-related inflammation (CRI) may lead to accumulation of random genetic alterations in cancer cells.
== History == Methylene blue has been described as "the first fully synthetic drug used in medicine". Methylene blue was first prepared in 1876 by German chemist Heinrich Caro. Its use in the treatment of malaria was pioneered by Paul Guttmann and Paul Ehrlich in 1891. During this period before World War I, researchers like Ehrlich believed that drugs and dyes worked in the same way, by preferentially staining pathogens and possibly harming them. Changing the cell membrane of pathogens is how various drugs work, so the theory was partially correct, although far from complete. Methylene blue continued to be used in World War II, where it was not well-liked by soldiers, who observed, "Even at the loo, we see, we pee, navy blue." It was discovered to be an antidote to carbon monoxide poisoning and cyanide poisoning in 1933 by Matilda Brooks. Methylene blue was the original prototype or lead compound for the design of many antimalarials including chloroquine, antihistamines, and antipsychotics including chlorpromazine.
The Romanian revolution (Romanian: Revoluția română) was a period of violent civil unrest in the Socialist Republic of Romania during December 1989 as a part of the revolutions of 1989 that occurred in several countries around the world, primarily within the Eastern Bloc. The Romanian revolution started in the city of Timișoara and soon spread throughout the country, ultimately culminating in the drumhead trial and execution of longtime Romanian Communist Party (PCR) General Secretary Nicolae Ceaușescu and his wife Elena, and the end of 42 years of Communist rule in Romania. It was also the last removal of a Marxist–Leninist government in a Warsaw Pact country during the events of 1989, and the only one that violently overthrew a country's leadership and executed its leader; according to estimates, over one thousand people died and thousands more were injured. Following World War II, Romania found itself inside the Soviet sphere of influence, with Communist rule officially declared in 1947. In April 1964, when Romania published a general policy paper worked out under Gheorghe Gheorghiu-Dej's instructions, the country was well on its way of carefully breaking away from Soviet control. Nicolae Ceaușescu became the country's leader the following year. Under his rule, Romania experienced a brief waning of internal repression that led to a positive image both at home and in the West. However, repression again intensified by the 1970s, and Ceaușescu's regime eventually became one of the most repressive in the world and one of the most repressive of modern times.
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.
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.