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Background And Research Context — 2026 Update

By Editorial Desk · published 2025-07-28 · last reviewed 2025-09-02 · Blog

A practical reference on LC-MS/MS: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.

This page was last updated on 2025-09-02 and is reviewed periodically as new material appears.

Background and Research Context

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.

Background and Regulatory Status

Legal status varies by country. In some places, cardarine is controlled under medicines or psychoactive substances laws; in others, it may be sold with minimal oversight as a research chemical. Customs agencies have intercepted shipments, and several national health agencies have issued warnings about products marketed for bodybuilding or performance enhancement. The lack of a standardized pharmaceutical supply means identity, purity, and contamination levels can differ widely between samples. These factors make cardarine a regulatory and public health concern rather than a conventional prescription drug.

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.

Cardarine at a glance

PropertyValueNotes
CAS Registry Number317318-70-0Unique identifier for the compound.
Chemical classPPARδ agonistSynthetic ligand for peroxisome proliferator-activated receptor delta.
AppearanceWhite to off-white solidTypical form of research-grade material.
SolubilitySoluble in DMSO and ethanolPoorly soluble in water.
Typical storage-20°CRecommended for long-term storage of stock solutions.

Mechanism and Laboratory Detection

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.

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.

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Mechanism and Detection

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.

Mechanism and Detection Methods

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.

Reference notes

GcMAF (or Gc protein-derived macrophage activating factor) is a protein produced by modification of vitamin D-binding protein. It has been promoted as a treatment for various medical conditions, but claims of its benefits are not supported by evidence.

=== Enzyme profiling === Identification of substrates for orphan enzymes Optimization of known enzyme substrates Elucidation of signal transduction pathways Detection of contaminating enzyme activities Consensus sequence and key residues determination Identifying sites for protein-protein interactions within a complex

Racemic menthol can also be formed by hydrogenation of thymol, menthone, or pulegone. In both cases with further processing (crystallizative entrainment resolution of the menthyl benzoate conglomerate) it is possible to concentrate the L-enantiomer, however this tends to be less efficient, although the higher processing costs may be offset by lower raw material costs. A further advantage of this process is that D-menthol becomes inexpensively available for use as a chiral auxiliary, along with the more usual L-antipode.

Aerogels are produced by extracting the liquid component of a gel through supercritical drying or freeze-drying. This allows the liquid to be slowly dried off without causing the solid matrix in the gel to collapse from capillary action, as would happen with conventional evaporation. The first aerogels were produced from silica gels. Kistler's later work involved aerogels based on alumina, chromia, and tin dioxide. Carbon aerogels were first developed in the late 1980s.

==== J ==== Jamón ibérico – "Iberian ham" (also called pata negra and carna negra; "black hoof") is an expensive variety of Jamón made out of black Iberian pigs, produced mostly in Spain, but also in some Portuguese regions where it is called presunto ibérico. Jamón serrano or simply Jamón – a type dry-cured ham from Spain, which is generally served in thin slices, or occasionally diced. One of the most famous foods of the Spanish cuisine. When produced from Iberian pork is commercially labeled jamón ibérico. Jerky – lean meat that has been trimmed of fat, cut into strips, and then dried to prevent spoilage. Normally, this drying includes the addition of salt, to prevent bacteria from developing on the meat before sufficient moisture has been removed. Modern manufactured jerky is normally marinated in a seasoned spice rub or liquid, and dried, dehydrated or smoked with low heat (usually under 70 °C/160 °F). Jinhua ham – a type of dry-cured ham named after the city of Jinhua, where it is produced, in the Zhejiang province of eastern China. The ham is used in Chinese cuisines to flavour stewed and braised foods as well as for making the stocks and broths of many Chinese soups.

Sources: en.wikipedia.org

Reference notes

1825 The first publication of the Gompertz–Makeham law of mortality that in the simplest form is: p = a + bx. According to the law, the probability of death p is defined as the sum of age-independent component a and the component depending on age bx which with age increases exponentially. If we place organisms in an absolutely protected environment and in this way make the first component negligible, the probability of death will be completely defined by the second component which actually describes the probability to die from aging. 1860s Alfred Russel Wallace writes down what is probably the first evolutionary theory of aging. In notes written sometime between 1865 and 1870, he proposed a wear and tear theory of aging, suggesting that older animals which continue to consume resources, competing with their offspring in an environment with limited food, were disfavored by natural selection. Therefore, he suggested that aging was an evolved trait which allowed an organism's descendants to thrive. 1882 August Weismann puts forward the wear and tear theory of aging independently of Wallace. 1889 Rejuvenation experiment conducted on himself by the French doctor Charles-Édouard Brown-Séquard. He made himself a few subcutaneous injections from the testicles of young dogs and guinea pigs and claimed that the injections were accompanied by significant and long pain, but then he observed an improvement of the physical condition of the organism and increase of mental activity.

No charges have been brought against the contractor because he does not fall under military jurisdiction; it is questionable whether any charges will or even can be brought against him. Donald Rumsfeld had said that army and government had only been informed in January and not in detail. On January 16, 2004, a press release was issued by the United States Central Command (CENTCOM) stating that an investigation had been initiated in response to allegations of detainee abuse at an unspecified detention facility (now known to be Abu Ghraib prison). In March 2004, 6 soldiers in Abu Ghraib were charged with dereliction of duty, cruelty and maltreatment, and sexual abuse. 17 others were suspended from duty, including the seven U.S. officers who ran the prison. Also recommended for discipline was Brig. Gen Janis Karpinski, the commander of the 800th brigade. The Red Cross, which had access to these prisons, has stated that the instances of torture were not aberrations but were systemic. Some officers have attempted to defend themselves by saying that they were only doing their duty. In response to ongoing complaints, the US military initiated a program to reform the internment and treatment systems. The reforms are expected to increase safeguards for prisoners' rights, to ensure each prisoner receives a copy of their internment order, and has their charges explained to them within 72 hours. They additionally plan to publicly post information about detainees so that family members can know what happened to their loved ones. Reforms were made in March 2004.

== Refusal == In the United States federal criminal system, refusing to take a drug test triggers an automatic revocation of probation or supervised release. In Victoria, Australia the driver of the car has the option to refuse the drug test. Refusing to undergo a drug test or refusing to undergo a secondary drug test after the first one, triggers an automatic suspension and disqualification for a period of two years and a fine of AUD$1000. The second refusal triggers an automatic suspension and disqualification for a period of four years and an even larger fine.

== Use == While originally invented as a tool to help university librarians to decide which journals to purchase, the impact factor soon became used as a measure for judging academic success. This use of impact factors was summarised by Hoeffel in 1998:

Sources: en.wikipedia.org

Frequently asked questions

What is cardarine?

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.

Is cardarine a steroid?

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.

What did animal studies find?

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.

Is cardarine approved for human use?

No. Major drug regulators have not approved GW501516 for treating any medical condition. Products sold as cardarine are typically unapproved research chemicals or supplements, so their contents and safety are not assured.

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