This is a working overview of Preclinical research, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-07-03 and is reviewed periodically as new material appears.
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.
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.
| 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 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.
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 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.
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.
Preclinical research reported that GW501516 increased running endurance in mice and improved lipid profiles in some animal species. Early human trials explored effects on high-density lipoprotein cholesterol, triglycerides, and glucose handling, but the program was discontinued. Published human data are sparse and do not establish efficacy for any condition. Studies also examined PPAR delta in cancer biology, with conflicting findings across models. The relationship between receptor activation, tissue context, and disease risk remains an active area of investigation.
L-RNA aptamers, built using L-ribose, are the enantiomers of natural oligonucleotides, which are made with D-ribose. Nucleic acid aptamers, including L-RNA aptamers, contain adenosine monophosphate, guanosine monophosphate, cytidine monophosphate, uridine monophosphate, a phosphate group, a nucleobase and a ribose sugar.
For several years, Valve secretly worked on Half-Life 2. Valve developed a new game engine, Source. It comes packaged with a heavily modified version of the Havok physics engine that allows for an extra dimension of interactivity in both single-player and online environments. In the episodic games that followed Half-Life 2, Valve made minor tweaks to the game's engine. In Episode One, Valve modified Alyx's AI to allow her to react to player actions. The game runs on an upgraded version of Valve's proprietary Source engine, and features both the engine's advanced lighting effects, and a new version of its facial animation/expression technology. The designer Robin Walker said Valve used Half-Life games to "solve some interesting collision of technology and art that had reared itself". For the original Half-Life, they expanded the role of narrative in FPS games; for Half-Life 2, they explored characters and physics systems, and refined these ideas in the Half-Life 2 episodes. Valve made several attempts to develop further Half-Life games, but could not settle on a direction and its flat management structure made it difficult for projects to gain momentum. Walker said Valve failed to find a unifying idea that provided a sense of "wonderment, or opening, or expansion". In January 2016, Laidlaw left Valve. He said he had tired of the FPS genre and that he had "always hoped that we'd stumble into a more expansive vocabulary or grammar for storytelling within the FPS medium, one that would let you do more than shoot or push buttons, or push crates".
Taken by mouth, valproate is rapidly and virtually completely absorbed from the gut. When in the bloodstream, 80–90% of the substance are bound to plasma proteins, mainly albumin. Protein binding is saturable: it decreases with increasing valproate concentration, low albumin concentrations, the patient's age, additional use of other drugs such as aspirin, as well as liver and kidney impairment. Concentrations in the cerebrospinal fluid and in breast milk are 1 to 10% of blood plasma concentrations. The vast majority of valproate metabolism occurs in the liver. Valproate is known to be metabolized by the cytochrome P450 enzymes CYP2A6, CYP2B6, CYP2C9, and CYP3A5. It is also known to be metabolized by the UDP-glucuronosyltransferase enzymes UGT1A3, UGT1A4, UGT1A6, UGT1A8, UGT1A9, UGT1A10, UGT2B7, and UGT2B15. Some of the known metabolites of valproate by these enzymes and uncharacterized enzymes include (see image):
Sources: en.wikipedia.org
== Structure == In humans, the gene for StAR is located on chromosome 8p11.23 and the protein has 285 amino acids. The signal sequence of StAR that targets it to the mitochondria is clipped off in two steps with import into the mitochondria. Phosphorylation at the serine at position 195 increases its activity. The domain of StAR important for promoting cholesterol transfer is the StAR-related transfer domain (START domain). StAR is the prototypic member of the START domain family of proteins and is thus also known as STARD1 for "START domain-containing protein 1". It is hypothesized that the START domain forms a pocket in StAR that binds single cholesterol molecules for delivery to P450scc. The closest homolog to StAR is MLN64 (STARD3). Together they comprise the StarD1/D3 subfamily of START domain-containing proteins.
=== Angevin transition === After the Polish royal line and Piast junior branch died out in 1370, Poland came under the rule of Louis I of Hungary of the Capetian House of Anjou, who presided over a union of Hungary and Poland that lasted until 1382. In 1374, Louis granted the Polish nobility the Privilege of Koszyce to assure the succession of one of his daughters in Poland. His youngest daughter Jadwiga (d. 1399) assumed the Polish throne in 1384.
=== 2000s === Hudson was named chairman of Sonic Corp. in January 2000. In September of 2002, Sonic Corporation introduced PartnerNet to its franchisees, an intranet array of services that for the first time, digitally linked all Sonic Drive-in locations to Sonic Corporation. The new intranet was via Hughes Satellite Services and provided advancements like credit card processing and video training. The compulsory service package was headlined with the introduction of Sonic Live Radio by StudioStream Signature Sound, featuring a toll-free request line, 866-SONIC-FM, and live on-air personalities. The live radio style was first of its kind for corporate America, later emulated by the likes of Walmart. Sonic Live Radio, in beta since 2001, was released to all locations in February 2003. Sonic gained further attention in 2003 following the release of comedic reality show The Simple Life starring Paris Hilton and Nicole Richie. Hilton and Richie, previously with no experience in having a job, had to work in a Sonic site in Altus, Arkansas. Celebrating its 50th birthday in 2003, Sonic briefly added the Birthday Cake Shake to the menu. As a part of the anniversary celebration, Pickle-O's made another appearance as a recurring item. Development milestones celebrated in the 2000s include the opening of the 3,000th Sonic Drive-In in Shawnee, Oklahoma, and the 3,500th Sonic Drive-In in the Chicago market (Algonquin, Illinois). In October 2004, President Pattye Moore stepped down to spend more time with her family.
Sources: en.wikipedia.org
== Mechanism of action == When a tumor stimulates the growth of new vessels, it is said to have undergone an 'angiogenic switch'. The principal stimulus for this angiogenic switch appears to be oxygen deprivation, although other stimuli such as inflammation, oncogenic mutations and mechanical stress may also play a role. The angiogenic switch leads to tumor expression of pro-angiogenic factors and increased tumor vascularization. Specifically, tumor cells release various pro-angiogenic paracrine factors (including angiogenin, vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), and transforming growth factor-β (TGF-β). These stimulate endothelial cell proliferation, migration and invasion resulting in new vascular structures sprouting from nearby blood vessels. Cell adhesion molecules, such as integrins, are critical to the attachment and migration of endothelial cells to the extracellular matrix.
== Membrane composition as a metabolic pacemaker == Studies on the cell membranes of mammals and reptiles discovered that mammalian cell membranes are composed of a higher proportion of polyunsaturated fatty acids (DHA, omega-3 fatty acid) than reptiles. Studies on bird fatty acid composition have noted similar proportions to mammals but with 1/3rd less omega-3 fatty acids as compared to omega-6 for a given body size. This fatty acid composition results in a more fluid cell membrane but also one that is permeable to various ions (H+ & Na+), resulting in cell membranes that are more costly to maintain. This maintenance cost has been argued to be one of the key causes for the high metabolic rates and concomitant warm-bloodedness of mammals and birds. However polyunsaturation of cell membranes may also occur in response to chronic cold temperatures as well. In fish increasingly cold environments lead to increasingly high cell membrane content of both monounsaturated and polyunsaturated fatty acids, to maintain greater membrane fluidity (and functionality) at the lower temperatures.
=== Other === In 2009, LifeVantage was sued by Utah-based Zrii LLC, a marketer of nutritional fruit drinks endorsed by Deepak Chopra, based on allegations that LifeVantage had conspired with former Zrii executives to "ruin the company" and take it over “on the cheap” following a "mass exodus". The case was closed in December 2009 following LifeVantage's settlement payment of $400,000 to Zrii. On October 14, 2011, Burke Hedges, a former LifeVantage distributor (hired for his background as a speaker and trainer) filed a lawsuit with the Utah District Court against LifeVantage and its executives, seeking $3 million in punitive damages over allegations of wrongful termination and tortious interference. In September 2016, a class action lawsuit was filed against LifeVantage in Utah alleging that the company and its executive Darren Jensen and Mark Jaggi made false and/or misleading statements, as well as failed to disclose material adverse facts about the Company's business, operations, and prospects. Specifically, the case alleged that the defendants made false and/or misleading statements and/or failed to disclose that: (i) LifeVantage lacked effective internal financial controls; (ii) as a result, the Company had improperly accounted for sales in certain international markets, along with associated revenue and income tax accruals; and (iii) as a result of the foregoing, LifeVantage's public statements were materially false and misleading at all relevant times. The case was dismissed in June 2017.
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.
No. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.