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 2026-08-01 and is reviewed periodically as new material appears.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
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.
| Property | Value | Notes |
|---|---|---|
| Chemical class | PPARδ agonist | Not an anabolic steroid. |
| Common synonyms | GW501516, GW-1516 | Cardarine is an informal name. |
| Appearance | White to off-white powder | Typical for research-grade solid. |
| Solubility class | Poorly soluble in water; soluble in some organic solvents | Such as DMSO or ethanol in laboratory settings. |
| Typical storage temperature | Cool, dry, protected from light | Specific conditions vary by supplier and form. |
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.
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.
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.
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.
=== Example values === Values for log Kow typically range between -3 (very hydrophilic) and +10 (extremely lipophilic/hydrophobic). The values listed here are sorted by the partition coefficient. Acetamide is hydrophilic, and 2,2′,4,4′,5-Pentachlorobiphenyl is lipophilic.
=== Metalloaminopeptidases === Metalloaminopeptidases require metal ions, such as zinc or manganese, in order to function. These enzymes can be identified by a conserved HEXXH motif in their active site. This motif is crucial for the enzyme's function, as the histidine amino acids within the motif coordinate (bind) the metal ion, which then uses hydrolysis to break the peptide bond between the first amino acid and the rest of the protein. Metalloaminopeptidases are the largest and most homogenous class of aminopeptidases; the MEROPS database identifies over 35 families to be part of the MA clan. This classification, which is based on structural similarities and evolutionary relationships, indicates a common ancestral origin for these enzymes. Examples of metalloaminopeptidases include aminopeptidase N (APN), leucine aminopeptidase (LAP), and aminopeptidase A (APA).
== Politics == His first foray into politics was as a student at the Mar Ivanios College where he founded a unit of Kerala Students Congress (Jacob) in 1994. In 1997, he was elected as editor of the college union magazine, Prathibha, which won the Malayala Manorama award for the state's best college magazine under his aegis. In 1998, he unsuccessfully contested the post of Chairman of the Mar Ivanios College Union. Anoop became State President of the Kerala Students Congress (Jacob) in 2001, during which period the party registered its best performance yet by winning seats including General Secretary & Councillor in colleges like Mar Ivanios. In 2008, he was elected as the State President of the Kerala Youth Front (Jacob), the youth wing of the Kerala Congress (Jacob) party.
Sources: en.wikipedia.org
l-Kynurenine is a metabolite of the amino acid l-tryptophan used in the production of niacin. Kynurenine is synthesized by the enzyme tryptophan dioxygenase, which is made primarily but not exclusively in the liver, and indoleamine 2,3-dioxygenase, which is made in many tissues in response to immune activation. An important source is the intestine. Kynurenine and its further breakdown products carry out diverse biological functions, including dilating blood vessels during inflammation and regulating the immune response. Some cancers increase kynurenine production, which increases tumor growth.
== Malignant neoplasm of bone, connective tissue, skin, and breast (170–175) == 170 Malignant neoplasm of bone and articular cartilage 170.9 Malignant neoplasm of bone and articular cartilage, site unspecified Ewing's sarcoma Osteosarcoma Chondrosarcoma 171 Malignant neoplasm of connective and other soft tissue Rhabdomyosarcoma 172 Malignant melanoma of skin 173 Other malignant neoplasm of skin 174 Malignant neoplasm of female breast 175 Malignant neoplasm of male breast
premature muscle fatigue (particularly for anaerobic activity and high-intensity aerobic activity, which may be described as inability to keep up with peers or reduced stamina); exercise-induced painful cramps; inappropriate rapid heart rate response to exercise; exaggerated cardiorespiratory response to exercise (heavy or rapid breathing with inappropriately rapid heart rate); second wind phenomenon (muscle fatigue and heart rate improve for aerobic activity after approximately 6–10 minutes). Heart rate during exercise is a key indicator as, unlike the symptoms of muscle fatigue and cramping, it is a medical sign (meaning that it is observable and measurable by a third party rather than felt subjectively by the patient). In regularly active individuals with McArdle disease, they may not feel the usual symptoms of muscle fatigue and cramping until they increase their speed to very brisk walking, jogging, or cycling; however, they will still show an inappropriately rapid heart rate response to exercise, with a declining heart rate once second wind has been achieved."In McArdle's, our heart rate tends to increase in what is called an 'inappropriate' response. That is, after the start of exercise it increases much more quickly than would be expected in someone unaffected by McArdle's."
Sources: en.wikipedia.org
=== Weight loss === Excess body weight is thought to be an important cause of sleep apnea. People who are overweight have more tissues in the back of their throat which can restrict the airway, especially when sleeping. In weight loss studies of overweight individuals, those who lose weight show reduced apnea frequencies and improved apnoea–hypopnoea index (AHI). Weight loss effective enough to relieve obesity hypoventilation syndrome (OHS) must be 25–30% of body weight. For some obese people, it can be difficult to achieve and maintain this result without bariatric surgery.
Owing to its location, the present territory of Colombia was a corridor of early human civilization from Mesoamerica and the Caribbean to the Andes and Amazon basin. The oldest archaeological finds are from the Pubenza and El Totumo sites in the Magdalena Valley 100 kilometers (62 mi) southwest of Bogotá. These sites date from the Paleoindian period (18,000–8000 BCE). At Puerto Hormiga and other sites, traces from the Archaic Period (~8000–2000 BCE) have been found. Vestiges indicate that there was also early occupation in the regions of El Abra and Tequendama in Cundinamarca. The oldest pottery discovered in the Americas, found in San Jacinto, dates to 5000–4000 BCE. Indigenous people inhabited the territory that is now Colombia by 12,500 BCE. Nomadic hunter-gatherer tribes at the El Abra, Tibitó and Tequendama sites near present-day Bogotá traded with one another and with other cultures from the Magdalena River Valley. A site including eight miles (13 km) of pictographs that is under study at Serranía de la Lindosa was revealed in November 2020. Their age is suggested as being 12,500 years old (c. 10,480 B.C.) by the anthropologists working on the site, because of extinct fauna depicted. It was during the earliest known human occupation of the area. Between 5000 and 1000 BCE, hunter-gatherer tribes transitioned to agrarian societies; fixed settlements were established, and pottery appeared.
== Resistance == Resistance to zalcitabine develops infrequently compared with other nRTIs, and generally only occurs at a low level. The most common mutation observed in vivo is T69D, which does not appear to give rise to cross-resistance to other nRTIs; mutations at positions 65, 74, 75, 184 and 215 in the pol gene are observed more rarely.
== Clinical significance == A deficiency of this protein may be responsible for dermatosparaxis, a genetic defect of connective tissues. Some hereditary forms of lymphedema are caused by mutations in ADAMTS3.
Sources: en.wikipedia.org
Cardarine is commonly known as GW501516 or GW-1516. These names refer to the same synthetic compound. It is not a brand-name approved medicine.
No, cardarine is not a steroid. It is classified as a PPARδ agonist. Its structure and receptor target differ from anabolic steroids.
No regulatory agency has approved cardarine as a medicine. It was investigated in early research but development was discontinued. It is not available as a prescription drug.
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.