PPAR delta comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-08-27. Numbers and descriptions here follow the published literature rather than marketing material.
GW501516 acts as a selective agonist at PPARδ, a nuclear receptor that regulates transcription of genes involved in lipid handling and energy metabolism. Activation of PPARδ in preclinical models increases fatty acid oxidation, mitochondrial biogenesis, and exercise endurance in rodents. These effects have made the compound a subject of metabolic research and also a target for sport anti-doping rules. In humans, however, controlled studies are limited, and whether similar endurance or metabolic changes occur at tolerated exposures remains an open question. The receptor’s broad tissue distribution also means downstream effects may vary by organ and condition.
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.
Laboratory studies have examined GW501516 in cell cultures and rodents for conditions such as dyslipidemia, insulin resistance, and obesity. Some trials in humans were initiated, but development was discontinued after preclinical findings raised concerns about cancer in certain models. Those findings do not prove that the compound causes cancer in people, but they contributed to regulatory caution. Later reviews often describe the evidence as preliminary and insufficient for assessing long-term safety.
In the fitness and bodybuilding literature, cardarine is frequently discussed as an endurance agent or fat-loss compound, although such claims are not supported by robust clinical evidence. Online descriptions often mix animal data, user anecdotes, and marketing language. Researchers who study PPARδ agonists distinguish between receptor activation in controlled experiments and unsupervised use of unverified products. The latter introduces unknown purity, dose, and interactions, making reported experiences difficult to interpret scientifically.
GW501516 acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in transcription of genes related to lipid handling and energy use. Activation of PPARδ can shift skeletal muscle toward greater fatty acid oxidation in animal models, which is one reason it drew interest for metabolic disease and exercise research. The exact downstream effects depend on tissue, species, dose, and duration. Human data are sparse, so many proposed benefits remain hypotheses rather than established clinical outcomes.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Visual description for typical solid reference material. |
| Solubility | Poorly soluble in water; soluble in DMSO | Solubility depends on solvent, purity, and form. |
| Storage | Cool, dry, protected from light | Long-term storage often uses low temperature and desiccant. |
| Common analytical method | LC-MS/MS | Used for detection and quantification in biological matrices. |
| Common synonyms | GW-501516; GW501516; endurobol | Naming varies among literature, vendors, and databases. |
Cardarine is frequently described as a fat-burning or endurance-enhancing supplement, but these claims exceed the available evidence. The compound is not a hormone, steroid, or selective androgen receptor modulator. Research articles discuss it as a tool compound for studying PPARδ biology, while anti-doping literature focuses on its abuse and detection. Quality of unapproved products is uncertain, and independent analyses have found impurities or incorrect labeling. Open questions include whether human cancer risk resembles that seen in rodents and how often non-athletes use the substance.
Cardarine has no approved therapeutic indication and is not marketed as a medicine. The World Anti-Doping Agency lists GW501516 as a prohibited substance at all times, covering both in-competition and out-of-competition periods. National laws vary: some countries treat it as an unapproved drug subject to import controls, while others have specific restrictions on sale for human consumption. It is often sold as a research chemical, a label that does not imply safety or legality. Enforcement actions have targeted online vendors and shipments.
Anti-doping laboratories identify GW501516 and related metabolites using liquid chromatography coupled with tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be analyzed. The method targets the parent compound and phase I and phase II metabolites, which extend the detection window. Because the substance is prohibited at all times, athletes can be tested outside competition. Detection limits and windows depend on the assay, sample type, and individual metabolism.
Analytical laboratories typically identify cardarine and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is a common matrix in anti-doping testing, while blood and tissue may be used in research settings. Detection windows depend on the assay, the sample matrix, and the compound's metabolism. Because cardarine is extensively metabolized, laboratories often target specific metabolites to improve sensitivity and confirmation. Reference standards are required for reliable quantification. Method validation includes checks for selectivity, linearity, and carryover.
A persistent misconception is that cardarine is a fat-burning drug or a safe alternative to anabolic steroids. No approved therapeutic product exists, and human safety data are limited. The tumor findings in rodents remain a central concern in scientific reviews. Products sold online may contain inaccurate labels, impurities, or different compounds entirely, which complicates any assessment of effects. Independent testing of such products has reported frequent mislabeling. For these reasons, discussions in the literature emphasize risks and unknowns rather than benefits.
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.
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.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
The area of a familiar country, state or city is often used as a size reference, especially in journalism. Usually the region is used to describe something of similar size to the reference region, but in some cases such references become common enough that multiples of the area start to be used, as in "twice the area of Wales". Besides Wales (20,779 km2 (8,023 sq mi)), other regions that have been used this way include Belgium (30,528 km2 or 11,787 mi2), the German state of Saarland (2,569.69 km2 or 992.16 mi2), and Washington, D.C. (61.4 mi2 or 159 km2).
Research on PFOA has demonstrated ubiquity, animal-based toxicity, and some associations with human health parameters and potential health effects. Additionally, advances in analytical chemistry in recent years have allowed the routine detection of low- and sub-parts per billion levels of PFOA in a variety of substances. In 2013, Gore-Tex eliminated the use of PFOAs in the manufacture of its weatherproof functional fabrics. Major companies producing PFOA signed with the Global PFOA Stewardship Program with the goal of elimination of PFOA by 2015. Since then it has been eliminated from the production of non-stick materials used in cookware. GenX has been introduced as a replacement for PFOA, but in a 2015 study which tested the effects on rats, GenX caused many of the same health problems as PFOA, but required much higher concentrations. This is because GenX (C3) is a short chain alternative to PFOA. GenX also has a significantly shorter half-life than PFOA so it is not as bio-persistent as PFOA or other long chain perfluorinated chemicals.
=== Nucleotides === Containing both amines or imines and phosphoric acid groups, the nucleotides such as AMP, ADP, and ATP exist significantly as zwitterions, although the positive and negative charges are not necessarily balanced.
Although councils had already suffered deep cuts under Labour in the 1970s, Heseltine was under pressure from Thatcher and from Conservative MPs and newspapers to cut more. Heseltine's initial suggestion, that councils who wanted to increase the rates be forced to submit to re-election, was rejected by the Cabinet, in favour of a proposal that such increases be put to referendum (in Coventry, voters had recently voted by over 7:1 for spending cuts rather than a supplementary rate increase). This proposal in turn was attacked by Conservative backbenchers, both as an infringement of council freedom and a risky precedent for national taxation, both in the Environment Committee and in the debate on a bill which Heseltine introduced and had to withdraw. Heseltine then banned supplementary rates and imposed stiffer sanctions on overspending councils. Thatcher's 1974 pledge to abolish the rates and replace them with a new form of local government funding was still in force. However, the 1979 manifesto made clear that income tax cuts took priority over rates reform. Thatcher also blocked the upward revaluation of property rating values in 1982. A review of rates reform was begun in 1981, in which his junior minister Tom King personally spoke to every single backbench Conservative MP to canvass opinion about the various options. A Green Paper was produced in December 1981, recommending that no single alternative to the rates suggested itself.
Sources: en.wikipedia.org
In April 2009, Kardashian and her sister Kourtney announced that they were contracted to star in a spin-off that would follow their move to launch a D-A-S-H store in Miami, Florida. The series, Kourtney and Khloé Take Miami, debuted on E! on August 16, 2009. Starting May 29, 2009, Kardashian joined Miami Top 40 Mainstream outlet WHYI for a weekly four-hour talk/entertainment program, co-hosted by 106 & Park's Terrence J. Khloé and her sisters Kim and Kourtney made a cameo appearance in the Season 3 premiere of the series 90210. Kardashian made an appearance in episodes 2, 4, and 8 of Kourtney and Kim Take New York, which premiered in January 2011. On April 10, 2011, Khloé & Lamar, Kardashian's own show with her then-husband, Lamar Odom, debuted. Kardashian participated in the second season of The Celebrity Apprentice, finishing 10th of 16 candidates by being fired by Donald Trump. It was reported she was fired because of her previous arrest for a DUI. In June 2009, Khloé and her sisters teamed up with the Natural Products Association to create a teeth whitening pen called Idol White. Kardashian appeared in one of PETA's "I'd Rather Go Naked Than Wear Fur" campaigns. The three sisters released a jewelry line in March 2010. In the spring of 2010, the sisters released a clothing line for Bebe. Bebe announced they were dropping the line in December 2010. In September 2010, Kardashian and her sisters released another clothing line, K-Dash on QVC. Kardashian and her sisters marketed a fake tan product, released in 2010 and called Kardashian Glamour Tan.
In September 2017, the company announced it would acquire Rigontec, developer of a candidate to target the retinoic acid-inducible gene I pathway, for $554 million. In October 2017, the company granted the inaugural Merck-AGITG Clinical Research Fellowship in Gastro-Intestinal (GI) Cancer to David Lau, a professional in Melbourne, Australia. In June 2018, Merck acquired Viralytics, an Australian viral cancer drug company, for AUD$502 million. In 2018, Merck began the submission process for a Biologics License Application to the Food and Drug Administration under the Breakthrough Therapy Designation for an investigational vaccine, called V920, to fight the Zaire strain of the Ebola virus. In April 2019, the company acquired Immune Design for approximately $300 million, gaining access to its immunotherapy programs. It also acquired Antelliq Group for $2.4 billion, or $3.7 billion including debt. In May 2019, Merck announced it would acquire Peloton Therapeutics, developer of a HIF-2alpha inhibitor for Von Hippel–Lindau disease-associated renal cell carcinoma, for up to $2.2 billion. In June 2019, Merck announced it would acquire Tilos Therapeutics for up to $773 million. In November 2019, the company acquired Calporta, which focused on Parkinsons and Alzheimers treatments. In December 2019, Merck Animal Health acquired Vaki, an aquaculture company, from Pentair.
Protein kinase N1 is responsible for the phosphorylation of the TNF receptor-associated factor (TRAF1) on serine 139 under specific conditions. Murine TRAF1 is also phosphorylated by the same kinase, which leads to the silencing of IKK/NF-κB activity. The elimination of phosphorylation on serine 139 can be achieved by the replacement of TRAF1 with an Alanine residue, which consequently leads to the improved recruitment of TBK1. At the serine 789 residue, FGFR1 is phosphorylated by RSK2 when the kinase is in its active form. The signaling capabilities of FGFR1 at the serine 777 site can be weakened by phosphorylation. Serine 1047 and serine 1048 have been linked to the decreased binding affinity of ubiquitin ligase c-Cbl to EFGR when they are phosphorylated. When serine 349 is phosphorylated, the binding affinity between protein complex p62 and the protein Keap1 is strengthened, which is linked to stress response. When serine 337 is phosphorylated by protein kinase A in vitro, the DNA binding efficiency of the p50 subunit of NF-κB is greatly increased. Phosphorylation of serine and threonine residues is known to crosstalk with O-GlcNAc modification of serine and threonine residues.
An internal process of natural selection occurs within the body and eventually mutations accumulate within cells to promote their own growth, creating a cancerous tumor that grows and invades various tissues of the body. Normally, a cell divides only in response to signals called growth factors and stops growing once in contact with surrounding cells and in response to growth-inhibitory signals. It usually then divides a limited number of times and dies, staying within the epithelium where it is unable to migrate to other organs. To become a cancer cell, a cell has to accumulate mutations in a number of genes (three to seven). A cancer cell can divide without growth factor and ignores inhibitory signals. Also, it is immortal and can grow indefinitely, even after it makes contact with neighboring cells. It may escape from the epithelium and ultimately from the primary tumor. Then, the escaped cell can cross the endothelium of a blood vessel and get transported by the bloodstream to colonize a new organ, forming deadly metastasis. Although there are some genetic predispositions in a small fraction of cancers, the major fraction is due to a set of new genetic mutations that originally appear and accumulate in one or a small number of cells that will divide to form the tumor and are not transmitted to the progeny (somatic mutations). The most frequent mutations are a loss of function of p53 protein, a tumor suppressor, or in the p53 pathway, and gain of function mutations in the Ras proteins, or in other oncogenes.
British garrisons in India contributed 18,534 British officers and men, as well as an estimated 10,000 Indian auxiliaries deployed to assist them. India also sent 7,000 horses, ponies and mules. Indian auxiliaries were only employed in non-combatant roles. The Natal Indian Ambulance Corps, created by Gandhi and financed by the local Indian community, served at the battles of Colenso and Spion Kop.
Sources: en.wikipedia.org
==== MeSH D12.125.166 – amino acids, sulfur ==== MeSH D12.125.166.175 – cystathionine MeSH D12.125.166.215 – cysteic acid MeSH D12.125.166.230 – cysteine MeSH D12.125.166.230.259 – acetylcysteine MeSH D12.125.166.230.310 – carbocysteine MeSH D12.125.166.230.330 – cysteinyldopa MeSH D12.125.166.230.369 – cystine MeSH D12.125.166.230.700 – selenocysteine MeSH D12.125.166.388 – ethionine MeSH D12.125.166.498 – homocysteine MeSH D12.125.166.498.050 – s-adenosylhomocysteine MeSH D12.125.166.554 – homocystine MeSH D12.125.166.676 – methionine MeSH D12.125.166.676.180 – s-adenosylmethionine MeSH D12.125.166.676.450 – n-formylmethionine MeSH D12.125.166.676.450.440 – n-formylmethionine leucyl-phenylalanine MeSH D12.125.166.676.620 – methionine sulfoximine MeSH D12.125.166.676.620.125 – buthionine sulfoximine MeSH D12.125.166.676.900 – selenomethionine MeSH D12.125.166.676.950 – vitamin u MeSH D12.125.166.786 – penicillamine MeSH D12.125.166.786.500 – s-nitroso-n-acetylpenicillamine MeSH D12.125.166.800 – thiopronine MeSH D12.125.166.893 – thiorphan
AMPT’s ability to deplete dopamine in the CNS makes it a promising target for treatment of dopamine related disorders. Metirosine is used in scientific research to investigate the effects of catecholamine depletion on behavior. There is evidence that catecholamine depletion causes an increase in sleepiness that is more pronounced than sleep deprivation, and that the fatigue lingers after the drug is discontinued. Catecholamine depletion has also been linked to a negative mood, though this is reported less often than sleepiness.
=== Decay by two or more processes === Some quantities decay by two exponential-decay processes simultaneously. In this case, the actual half-life T½ can be related to the half-lives t1 and t2 that the quantity would have if each of the decay processes acted in isolation:
==== Testosterone ==== Testosterone is secreted by the testicles of males and the ovaries of females, although small amounts are also secreted by the adrenal glands. It is the principal male sex hormone and an anabolic steroid. See Testosterone: Aggression and criminality and Testosterone: Brain for more information on how testosterone effects behavior.
Sources: en.wikipedia.org
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.
Most methods use liquid chromatography with tandem mass spectrometry. Urine is common in anti-doping testing, and blood or plasma may be used in research.
Typical guidance is cool, dry, dark storage, often at low temperature and with desiccant. Stability data are limited, so storage conditions should be verified for each batch or supplier.
It binds and activates PPARδ, a nuclear receptor that influences gene expression related to fatty acid metabolism and energy balance. This mechanism has been studied mainly in animals and cell models, not established as a safe human therapy.