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.
This page was last updated on 2025-08-25 and is reviewed periodically as new material appears.
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.
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.
Laboratory studies indicate that GW501516 activates PPARδ, a nuclear receptor involved in fatty acid oxidation and energy metabolism. In rodent experiments, treated animals often showed increased endurance and reduced fat mass. These effects were observed under controlled conditions and do not establish safe or effective use in humans. The exact dose-response relationship in humans remains poorly characterized. Species differences in metabolism can affect how results translate across animals and people.
| Property | Value | Notes |
|---|---|---|
| IUPAC name | {4-[({4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl}methyl)sulfanyl]phenoxy}acetic acid | Systematic name for GW501516 |
| CAS Registry Number | 317318-70-0 | Unique identifier for the parent compound |
| Molecular formula | C21H18F3NO3S2 | Includes carbon, hydrogen, fluorine, nitrogen, oxygen, and sulfur |
| Molecular weight | 453.5 g/mol | Approximate value for the neutral form |
| Appearance | White to off-white powder | Typical description for purified laboratory material |
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.
At the molecular level, GW501516 binds and activates PPARδ, a nuclear receptor that regulates transcription. Activation shifts expression of genes involved in fatty acid oxidation, energy expenditure, and lipid transport in skeletal muscle and liver. Animal studies report increased endurance and altered lipid profiles after exposure. Human data are limited to small trials and do not establish long-term safety or efficacy. PPARδ also has roles in cell proliferation, so the relationship between activation and cancer risk remains an open question.
Published literature on cardarine includes in vitro assays, rodent experiments, and a small number of human studies. Reports describe effects on exercise capacity and lipid metabolism in animals, while human evidence is sparse. Many online descriptions present the compound as a proven endurance aid, a claim not supported by regulatory approval or large clinical trials. Analytical studies focus on identifying the parent compound and its metabolites in biological samples. Important uncertainties include species differences, dose-response relationships, and the relevance of rodent tumor findings to humans.
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.
O' Coffee Club (commonly known as Coffee Club) is a Singaporean coffee house and restaurant chain. The chain was founded in Holland Village in 1991 as a 2-storey establishment and has since expanded to 23 outlets in Singapore, 6 in Malaysia and 4 in Indonesia. O' Coffee Club serves hot and cold drinks, including coffees, teas, iced teas, juices, smoothies and milkshakes. The chain also offers full-course meals at its outlets, as well as desserts and other baked goods.
==== Czech Republic ==== Possession of more than 200 mg of 2C-B is punishable with a two years jail sentence. Smaller amount is punishable by a fine. The 200 mg threshold is merely a guideline which the court can reconsider depending on circumstances.
== Side effects == Side effects of orexin receptor antagonists include somnolence, daytime sleepiness and sedation, headache, abnormal dreams, fatigue, and dry mouth. Rates of somnolence or fatigue with orexin receptor antagonists in clinical trials were 7% (vs. 3% with placebo) for suvorexant 15 to 20 mg, 7 to 10% (vs. 1.3% for placebo) for lemborexant 5 to 10 mg, and 5 to 6% (vs. 4% with placebo) for daridorexant 25 to 50 mg.
Cells receive information from their neighbors through a class of proteins known as receptors. Receptors may bind with some molecules (ligands) or may interact with physical agents like light, mechanical temperature, pressure, etc. Reception occurs when the target cell (any cell with a receptor protein specific to the signal molecule) detects a signal, usually in the form of a small, water-soluble molecule, via binding to a receptor protein on the cell surface, or once inside the cell, the signaling molecule can bind to intracellular receptors, other elements, or stimulate enzyme activity (e.g. gasses), as in intracrine signaling. Signaling molecules interact with a target cell as a ligand to cell surface receptors, and/or by entering into the cell through its membrane or endocytosis for intracrine signaling. This generally results in the activation of second messengers, leading to various physiological effects. In many mammals, early embryo cells exchange signals with cells of the uterus. In the human gastrointestinal tract, bacteria exchange signals with each other and with human epithelial and immune system cells. For the yeast Saccharomyces cerevisiae during mating, some cells send a peptide signal (mating factor pheromones) into their environment. The mating factor peptide may bind to a cell surface receptor on other yeast cells and induce them to prepare for mating.
Sources: en.wikipedia.org
=== Insulin resistance === Isoleucine, like other branched-chain amino acids, is associated with insulin resistance: higher levels of isoleucine are observed in the blood of diabetic mice, rats, and humans. In diet-induced obese and insulin resistant mice, a diet with decreased levels of isoleucine (with or without the other branched-chain amino acids) results in reduced adiposity and improved insulin sensitivity. Reduced dietary levels of isoleucine are required for the beneficial metabolic effects of a low protein diet. In humans, a protein restricted diet lowers blood levels of isoleucine and decreases fasting blood glucose levels. Mice fed a low isoleucine diet are leaner, live longer, and are less frail. In humans, higher dietary levels of isoleucine are associated with greater body mass index.
Other Marvel Comics adaptations have also had success with the Spider-Man and X-Men properties, while films based on Batman and Superman from DC Comics have generally performed well. Beyond the superhero genre, Star Wars, with four films, is the most represented franchise in the nominal earnings chart. Although the nominal earnings chart is dominated by films adapted from pre-existing properties and sequels, it is headed by Avatar, which is an original work. Animated family films have performed consistently well, with Disney films enjoying lucrative re-releases prior to the home-video era. Disney also enjoyed later success with films such as Frozen and its sequel, Zootopia and its sequel, and The Lion King (along with its computer-animated remake), as well as its Pixar division, of which Inside Out 2, Incredibles 2, and Toy Story 3, 4 and 5 have been the best performers. Beyond Disney and Pixar animation, China's Ne Zha 2 (the highest-grossing animated film), and the Despicable Me and Shrek series have met with the most success. While inflation has eroded the achievements of most films from the 1960s and 1970s, there are franchises originating from that period that are still active. Besides the Star Wars franchise, James Bond films are still being released periodically; both are among the highest-grossing franchises. Some of the older films that held the record of highest-grossing film still have respectable grosses by today's standards, but no longer compete numerically against today's top-earners in an era of much higher individual ticket prices.
=== Early work: 1924-1933 === In 1926, while at the University of Leipzig, Schoenheimer developed a method of synthesising peptides. From 1903 to 1909, Emil Fischer's scientific work had prompted the synthesis of many peptides, however there were limitations to his method. Fischer used a halogen acyl amino acid halide coupling method. A suitable method was needed, which involved an amino blocking group being removed by a nonhydrolyptic process. This method was first proposed by Rudolph Schoenheimer, as he utilised earlier findings by Michel Bergmann which demonstrated that with a mixture of hydrogen iodide and phosphonium iodide, p-toluenesulfonyl amino acids could be detosylated reductively. Schoenheimer used the azide coupling method introduced by Theodor Curtius, and the acid chloride method introduced by Emil Fischer in order to make several peptides. In 1929, Schoenheimer investigated how different sterols impacted cholesterol deposition in rabbits. It had been assumed that only plants were able to synthesize complex compounds whilst animals were forced to obtain these compounds indirectly from plants. It was assumed also that there would only small chemical changes were necessary when modifying these compounds to suit specific needs. Previous cholesterol-balance studies indicated that under specific conditions, animals could possess the ability to form cholesterol, as it has been discovered that sometimes negative balances are present in metabolic studies, wherein more sterol is excreted than consumed.
Rabbit-skin glue is a type of animal glue used as a sizing and an adhesive. It is essentially refined rabbit collagen. The glue has been used for centuries for stretching and priming canvases for oil painting. It is also an ingredient in traditional gesso.
=== Dentinal sclerosis === Dentinal sclerosis or transparent dentin sclerosis of primary dentin is a change in the structure of teeth characterized by calcification of dentinal tubules. It can occur as a result of injury to dentin by caries or abrasion, or as part of the normal aging process.
Sources: en.wikipedia.org
An example calculation for the distance to the supernova point of origin is given below. This calculation uses speculative values for terrestrial 60Fe atom surface density (N60 ≈ 4 × 1011 atoms/m2) and a rough estimate of the mass of 60Fe ejected by a supernova (10×10−5 M☉).
Such deterioration is similar to the one produced in MS patients due to heat, fever or stress (Uhthoff's phenomenon), usually appears within 24 hours of treatment, is more common in the initial months of treatment, and may last several days. A symptom specially sensitive to worsening is spasticity. Interferon-beta can also reduce numbers of white blood cells (leukopenia), lymphocytes (lymphopenia) and neutrophils (neutropenia), as well as affect liver function. In most cases these effects are non-dangerous and reversible after cessation or reduction of treatment. Nevertheless, recommendation is that all patients should be monitored through laboratory blood analyses, including liver function tests, to ensure safe use of interferons. To help prevent injection-site reactions, patients are advised to rotate injection sites and use an aseptic injection technique. Injection devices are available to optimize the injection process. Side effects are often onerous enough that many patients ultimately discontinue taking interferons (or glatiramer acetate, a comparable disease-modifying therapy requiring regular injections).
The word pharmacy is derived from Old French farmacie "substance, such as a food or in the form of a medicine which has a laxative effect" from Medieval Latin pharmacia from Greek pharmakeia (Ancient Greek: φαρμακεία) "a medicine", which itself derives from pharmakon (φάρμακον), meaning "drug, poison, spell" (which is etymologically related to pharmakos).
=== Beginnings of molecular cytogenetics === In the 1980s, advances were made in molecular cytogenetics. While radioisotope-labeled probes had been hybridized with DNA since 1969, movement was now made in using fluorescent-labeled probes. Hybridizing them to chromosomal preparations using existing techniques came to be known as fluorescence in situ hybridization (FISH). This change significantly increased the usage of probing techniques as fluorescent-labeled probes are safer. Further advances in micromanipulation and examination of chromosomes led to the technique of chromosome microdissection whereby aberrations in chromosomal structure could be isolated, cloned, and studied in ever greater detail.
Sources: en.wikipedia.org
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.
It is prohibited by the World Anti-Doping Agency as a hormone and metabolic modulator. Athletes who test positive for GW501516 can face sanctions, including suspensions and loss of results.
Cardarine is a common or trade-style name, while GW501516 is the research code for the same chemical entity. Some sources also use Endurobol or GSK-516. The names refer to the same compound, not distinct drugs.
Rodent studies reported increased endurance and fat oxidation after GW501516 exposure. Long-term studies also found higher rates of some tumors, which led to halted development.