Reference standard 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.
Last reviewed on 2026-03-27. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Cardarine is the common name for GW501516, a synthetic compound studied as a peroxisome proliferator-activated receptor delta agonist. Researchers developed it to explore treatments for lipid disorders and metabolic conditions. It is not an approved medicine in any country. Early clinical work examined changes in HDL cholesterol and triglycerides, but development was discontinued after animal studies raised concerns about cancer. The compound remains available as a research chemical and appears in discussions of performance enhancement.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common name | Cardarine | Also called GW501516 and endurobol. |
| Chemical formula | C21H18F3NO3S2 | Molecular weight about 453.5 g/mol. |
| Appearance | White to off-white solid | Form depends on synthesis and purity. |
| Solubility | Soluble in DMSO and ethanol | Low solubility in water. |
| Typical storage | -20 °C, desiccated, protected from light | Common for research chemicals. |
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
Cardarine is a common name for GW501516, a synthetic compound studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
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.
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.
Cardarine is explicitly prohibited by the World Anti-Doping Agency under the class of PPARδ agonists. Its presence in urine or blood samples can be detected using mass spectrometry-based methods, often liquid chromatography-tandem mass spectrometry. Athletes who test positive may face sanctions, including bans from competition. The compound is also regulated as a prescription-only or unapproved drug in many countries. Enforcement varies by jurisdiction, and some regions treat it as a controlled substance. Online sales may occur despite these restrictions, creating quality and legal risks.
Laboratory detection of cardarine typically involves sample preparation followed by chromatographic separation and mass spectrometric identification. Urine is the most common matrix for anti-doping tests, though blood and hair have also been explored. Methods can target the parent compound or its metabolites, depending on the expected window of detection. Reference standards are required for accurate quantification. Matrix effects and dilution can influence results, so laboratories use internal standards and validation protocols. The exact detection window varies with dose, route, and individual metabolism.
== Types == Nano-materials are often categorized as to how many of their dimensions fall in the nanoscale. A nanoparticle is defined a nano-object with all three external dimensions in the nanoscale, whose longest and the shortest axes do not differ significantly. A nanofiber has two external dimensions in the nanoscale, with nanotubes being hollow nanofibers and nanorods being solid nanofibers. A nanoplate/nanosheet has one external dimension in the nanoscale, and if the two larger dimensions are significantly different it is called a nanoribbon. For nanofibers and nanoplates, the other dimensions may or may not be in the nanoscale, but must be significantly larger. In all of these cases, a significant difference is noted to typically be at least a factor of 3. Nanostructured materials are often categorized by what phases of matter they contain. A nanocomposite is a solid containing at least one physically or chemically distinct region or collection of regions, having at least one dimension in the nanoscale. A nanofoam has a liquid or solid matrix, filled with a gaseous phase, where one of the two phases has dimensions on the nanoscale. A nanoporous material is a solid material containing nanopores, voids in the form of open or closed pores of sub-micron lengthscales. A nanocrystalline material has a significant fraction of crystal grains in the nanoscale.
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== Physical properties == Ciprofol is an optically active 2,6-disubstituted alkylphenol with a cyclopropylethyl group incorporated at the second carbon atom. This cyclopropyl group increases the steric effects and introduces stereoselective effects over its anesthetic properties. These properties appear to increase the anesthetic potency of ciprofol, when compared with propofol.
=== Urinary preparations === Purified urinary FSH (75 IU FSH and ≤ 2 IU of LH) Generic urofollitropin for injection, purified. Brands Bravelle, U.S., (≤ 2 IU LH) Metrodin, U.S. and Canada, (≤ 1 IU LH) Fertinorm Hp, (Canada) Highly purified urinary FSH (75 IU FSH and ≤ 0.1 IU LH/1000 IU FSH) Generic urofollitropin for injection, (highly) purified. Brands Fertinex (≤ 0.1 IU LH/1000 IU FSH)
heterokaryon A multinucleate cell containing nuclei with different genotypes, resulting from the fusion of two or more genetically distinct cells, either naturally (e.g. in certain types of sexual reproduction) or artificially (e.g. in genetic engineering).
Sources: en.wikipedia.org
Morphine became a controlled substance in the US under the Harrison Narcotics Tax Act of 1914, and possession without a prescription in the US is a criminal offense. Morphine was the most commonly abused narcotic analgesic in the world until heroin was synthesized and came into use. In general, until the synthesis of dihydromorphine (c. 1900), the dihydromorphinone class of opioids (1920s), and oxycodone (1916) and similar drugs, there were no other drugs in the same efficacy range as opium, morphine, and heroin, with synthetics still several years away (pethidine was invented in Germany in 1937) and opioid agonists among the semi-synthetics were analogues and derivatives of codeine such as dihydrocodeine (Paracodin), ethylmorphine (Dionine), and benzylmorphine (Peronine). Even today, morphine is the most sought-after prescription narcotic by heroin addicts when heroin is scarce, all other things being equal; local conditions and user preference may cause hydromorphone, oxymorphone, high-dose oxycodone, or methadone as well as dextromoramide in specific instances such as 1970s Australia, to top that particular list. The stop-gap drugs used by the largest absolute number of heroin addicts is probably codeine, with significant use also of dihydrocodeine, poppy straw derivatives like poppy pod and poppy seed tea, propoxyphene, and tramadol. The structural formula of morphine was determined by 1925 by Robert Robinson.
=== Legal recognition of denturists === The 1919 Tasmanian Dental Act made a clear distinction between the role of a Dentist and the practice of denture making. For a patient that required dentures, a consultation by referral from a Dentist became normal procedure. Denturism – that is the field of dentures - was not recognised until more recent times. The Health Amendment Act (1933) was the first legal document that gave rise to the practice of Denturism in Canada. The Dental Mechanics Act of Alberta (1961) was the future update to this legislation allowing Denturists to begin work in the field. They were also known as "Dental Mechanics" or "Denture Therapists." This gave rise for the need for legal recognition of denturists in other countries. In the United States, the first legally recognised Denturists were found in Oregon, 1971. In 1974, denturists were first legally recognised and in 1978, Denture Therapists began practicing. The increasing rate of ill-fitting, misaligned, unstable and unsupportive dentures motivated three Denturists in 1956 to pursue international recognition. Rolf Pfenniger, Hannes Stiebler and Stephan Grabert formed the Internationale Arbeitsgemeinschaft der Zahnprothetiker. In English, this is the International Federation of Denturists. Denturists have campaigned for the right to practice independently in many states, with the argument that they can provide greater access and lower-cost prosthetic services. This argument has been disproved by examining other jurisdictions in the world which have both dentists and denturists.
== Contraindications == Benzodiazepines require special precaution if used in the elderly, during pregnancy, in children, alcohol or drug-dependent individuals and individuals with comorbid psychiatric disorders. Phenazepam should not be taken with alcohol or any other CNS depressants. Phenazepam should not be used therapeutically for periods of longer than one month including tapering on and off the drug as recommended for any benzodiazepine in the British national formulary. Some patients may require longer term treatment. Phenazepam was found to be a component in some "herbal incense" mixtures in Australia and New Zealand in 2011, namely "Kronic". The particular product variety was withdrawn from the market shortly after and replaced with a new formulation.
=== Excessive sleepiness === Selegiline has been evaluated for the treatment of narcolepsy in three small clinical studies. It was found to be effective in these studies. A dosage of 10 mg/day had no effect on symptoms, but 20 to 30 mg/day improved alertness, mood, and somewhat reduced cataplexy, clinical effects that have been described as comparable to the same dosages of amphetamine. Animal research indicates that the beneficial effects of high doses of selegiline in narcolepsy are likely due to conversion into its active metabolites, levoamphetamine and levomethamphetamine. Selegiline has also been evaluated for treatment of hypersomnia (excessive sleeping or sleepiness) in people with myotonic dystrophy, but its effectiveness was very uncertain.
The United States has a growing problem with counterfeit drugs. In 2012, tainted steroids killed 11 people near Boston and sickened another 100. In another case, vials of the cancer medicine Avastin were found to contain no active ingredients. The vials were sourced in Turkey, shipped to Switzerland, then Denmark, finally to the United Kingdom from which they were exported to U.S. wholesale distributors. The Wall Street Journal reported that the U.S. wholesale distributor was hired by Canada Drugs, which also owns CanadaDrugs.com, a retail pharmacy website that sells prescription medication internationally, with a focus on the American market. Between 2007 and 2008, 149 Americans died from a contaminated blood thinner called Heparin that was legally imported into the United States. Investigated by the FDA Office of Criminal Investigations, the Albers Medical investigation is the most prolific example to date. In August 2005, the U.S. Attorney's Office for the Western District of Missouri issued a press release announcing that three businesses and eleven individuals were indicted for their involvement in a $42 million conspiracy to sell counterfeit, smuggled and misbranded Lipitor and other drugs and for participating in a conspiracy to sell stolen drugs. As part of this investigation, the FDA initiated a recall of more than 18 million Lipitor tablets, which ranks as the largest recall in the history of criminal investigations of counterfeit medications. Participants in this scheme conspired to purchase and sell counterfeit, misbranded and illegally imported drugs.
Sources: en.wikipedia.org
Cardarine is a common name for the investigational compound GW501516. It acts as a PPARδ agonist and is not approved for human use. It is prohibited in sport.
It activates PPARδ, a nuclear receptor that influences gene expression related to lipid and energy metabolism. Animal studies show changes in endurance and lipid levels. Human effects and risks are not well established.
No, cardarine is not a steroid. It belongs to a different chemical class, the PPARδ agonists. It is also not a selective androgen receptor modulator.
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.