This is a working overview of fatty acid oxidation, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-14. Anything still debated is marked as such rather than presented as settled.
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 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.
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
| 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. |
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.
Safety concerns emerged from long-term animal studies. In rodents given the compound for extended periods, researchers found an increased incidence of certain cancers, including liver and bladder tumors. These findings contributed to the discontinuation of clinical development. Whether similar risks apply to short-term or low-level exposure in humans is not established, and controlled human safety data are limited. The relevance of high-dose rodent carcinogenicity findings to human use remains a subject of debate.
Human trials of GW501516 were small and short in duration. They examined lipid levels, glucose handling, and other metabolic markers, but the programs were halted after the animal cancer findings. No approved therapeutic product exists, and published human data are insufficient for establishing long-term safety. Reports of use for athletic performance come mainly from non-clinical settings and cannot be verified through controlled trials. Independent testing of products sold as cardarine has found inconsistent purity and labeling.
== Career == McAlpine returned to Canada after her PhD to work as a postdoctoral fellow at Queen's University from 1970 to 1972 in the group of Nancy Simpson. McAlpine participated in a project to study genetic traits of peoples in the Arctic, living in northern Canada for a month in 1970. In 1972, she started working at the University of Manitoba. Her main research focus was on mapping human genes. She served on the university senate between 1981 and 1985 and was Chair of the University Discipline Committee between 1990 and 1994. She was granted full professorship in 1985. From 1993 until her death, she was Chair of the Department of Human Genetics. McAlpine was part of a group of geneticists who recognised the importance of standardised nomenclatures across all human genes and homologous genes in other species. She founded the HUGO Gene Nomenclature Committee and was Chair of the committee from 1992 until 1996. When she retired, her workload was so significant as to be divided between three full-time staff members. She contributed to the creation of guidelines and provided pre-publication services to researchers to ensure consistent gene labelling. She became known as the foremost expert and leader in gene nomenclature. McAlpine was also a member of the American Society of Human Genetics since 1965 and was president of the Genetics Society of Canada in 1995. She was President of the Manitoba Chapter of the Canadian Association of Women in Science in 1993–1994.
== Rearmament of Hezbollah == Event though the ceasefire agreement was signed by both parties, immediately after Hezbollah began its rearmament. According to Israeli and Arab intelligence sources, the organization is using the Beirut seaport and its old smuggling land routes from Syria, for bringing in long range missiles, antitank missiles, rockets, and artillery shells. It is also reported that, Hezbollah is manufacturing weapons. The efforts take place mainly in the suburbs of Beirut and the Bekaa Valley.
==== Above-ground disposal ==== Dry cask storage typically involves taking waste from a spent fuel pool and sealing it (along with an inert gas) in a steel cylinder, which is placed in a concrete cylinder which acts as a radiation shield. It is a relatively inexpensive method which can be done at a central facility or adjacent to the source reactor. The waste can be easily retrieved for reprocessing.
Sources: en.wikipedia.org
=== Stereochemistry === Panthenol comes in two enantiomers: D, and L. Only D-panthenol (dexpanthenol) is biologically active, however both forms have moisturizing properties. For cosmetic use, panthenol comes either in D form, or as a racemic mixture of D and L (DL-panthenol).
=== Films depicting Cold War espionage === Tinker Tailor Soldier Spy is a 2011 Cold War spy thriller adaptation of the 1974 John le Carré novel of the same name. It is set in London in the early 1970s and follows the hunt for a Soviet double agent at the top of the British secret service. The Spy Who Came In from the Cold is a 1965 British Cold War spy film based on the 1963 John le Carré novel. The film depicts a British agent's mission as a faux defector to East Germany to sow damaging disinformation about a powerful East German intelligence officer. Firefox is a 1982 film based on a Craig Thomas novel of the same name. The plot details an American plot to steal a highly advanced Soviet fighter aircraft (MiG-31 Firefox) which is capable of Mach 6, is invisible to radar, and carries weapons controlled by thought. The Hunt for Red October is a 1990 film based on the 1984 Tom Clancy novel of the same name about the captain of a technologically advanced Soviet ballistic missile submarine that attempts to defect to the United States. James Bond first appeared in 1953. While the primary antagonists in the majority of the novels were Soviet agents, the films were only vaguely based on the Cold War. The Bond movies followed the political climate of the time in their depictions of Soviets and "Red" Chinese.
== Responses == The Government of Indonesia, especially the leading figures from People's Consultative Assembly, called the flag a threat to the national unity of Indonesia and declared it a symbol of treason and sedition. Various government institutions, such as the Banten regional police, attempted to ban the flag. Meanwhile, the deputy speaker of DPR Sufmi Dasco Ahmad and West Java governor Dedi Mulyadi found no problem with its raising. Minister of State Secretariat Prasetyo Hadi said that President Prabowo had no issues with protesters raising the flag and considered it as freedom of speech, but urged people not to "compare it to, tarnish it, or put it in conflict with the Red and White flag". The Guardian described the flag as "a symbol of defiance and hope for gen Z protesters" which has "resonated across borders". Tokoro Ikuya (床呂郁哉), professor of Tokyo University of Foreign Studies who studies Japanese popular culture, indicated that the flag serves as "an icon conveys a message that could be understood beyond minor different positions". Animanga expert Andrea Horbinski remarked that the flag was a natural uniting symbol, since Gen Z protesters knew that protesters would be familiar with it due to the series' popularity.
Sources: en.wikipedia.org
Igloos – built by the Inuit, igloos were constructed for many centuries as a form of protection and shelter to house people from the harsh Arctic weather. While the temperature outside an igloo may have been −45 °C (−49 °F), the temperature within an igloo was stable ranging from −7 to 16 °C (19 to 61 °F) when warmed by body heat. The Central Inuit in Northern Canada (especially those, who lived around the Davis Strait), lined the inside living area of an igloo with animal skin and hides. This assisted in increasing the temperature within an igloo from around 2 °C (36 °F) to 10–20 °C (50–68 °F), thereby insuring a more comfortable existence for the inhabitants of the igloo from the fierce cold outside. With the addition of a qulliq the temperature could be raised even more. Inca road systems – the Inca built one of the most extensive road systems in the ancient world. The Incas built upon the roads, which were originally constructed by previous Andean civilizations such as the Chimu, Nazca, Wari, Moche, and others. The Inca also further refined and expanded upon the earlier innovations and systems laid in place by previous Indigenous cultures. The Incan road system, at its peak, spanned over 20,000 mi (32,000 km) and crisscrossed mountains, rivers, deserts, rainforests, and plains. The road system connected the empire from the Andes mountain in Colombia all through Ecuador, Peru, Bolivia, northeastern Argentina, and present-day northern Chile.
=== Stimulation of glycogen synthesis === Glycogen synthesis is also stimulated by the insulin receptor via IRS-1. In this case, it is the SH2 domain of PI-3 kinase (PI-3K) that binds the P-Tyr of IRS-1. Now activated, PI-3K can convert the membrane lipid phosphatidylinositol 4,5-bisphosphate (PIP2) to phosphatidylinositol 3,4,5-triphosphate (PIP3). This indirectly activates a protein kinase, PKB (Akt), via phosphorylation. PKB then phosphorylates several target proteins, including glycogen synthase kinase 3 (GSK-3). GSK-3 is responsible for phosphorylating (and thus deactivating) glycogen synthase. When GSK-3 is phosphorylated, it is deactivated, and prevented from deactivating glycogen synthase. In this roundabout manner, insulin increases glycogen synthesis.
=== Distribution === The plasma protein binding of testosterone is 98.0 to 98.5%, with 1.5 to 2.0% free or unbound. It is bound 65% to sex hormone-binding globulin (SHBG) and 33% bound weakly to albumin.
Minoxidil causes a redistribution of cellular iron through its apparent capacity to bind this metal ion. By binding iron in a Fenton-reactive form, intracellular hydroxyl radical production would ensue, but hydroxyl would be immediately trapped and scavenged by the minoxidil to generate a nitroxyl radical. It is presumed that this nitroxyl radical will be capable of reduction by glutathione to reform minoxidil. Such a process would cycle until the minoxidil is otherwise metabolized and would result in rapid glutathione depletion with glutathione disulphide formation and therefore with concomitant consumption of NADPH/NADH and other reducing equivalents. Minoxidil inhibited PHD by interfering with the normal function of ascorbate, a cofactor of the enzyme, leading to a stabilization of HIF-1α protein and a subsequent activation of HIF-1. In an in vivo angiogenesis assay, millimolar minoxidil increased blood vessel formation in a VEGF-dependent manner. Minoxidil inhibition of PHD occurs via interrupting ascorbate binding to iron. The structural feature of positioning amines adjacent to nitric oxide may confer the ability of millimolar minoxidil to chelate iron, thereby inhibiting PHD. Minoxidil is capable of tetrahydrobiopterin inhibition as a cofactor for nitric oxide synthase. Minoxidil stimulates prostaglandin E2 production by activating COX-1 and prostaglandin endoperoxide synthase-1 but inhibits prostacyclin production.
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.
It targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not act primarily on androgen receptors. This distinction separates it from SARMs.