Cardarine is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-02-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Handling and quality assessment of cardarine reference material follow general laboratory practices for poorly characterized compounds. It typically appears as a white to off-white powder and is sparingly soluble in water but soluble in organic solvents such as dimethyl sulfoxide and ethanol. Storage recommendations usually specify a cool, dry, dark place, with long-term storage at low temperature and desiccation. Purity may be checked by high-performance liquid chromatography with ultraviolet detection, while identity is confirmed by mass spectrometry and nuclear magnetic resonance. No pharmacopeial monograph exists, so reported purity and stability depend on the supplier’s methods.
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.
Products sold as cardarine have been found to contain incorrect compounds, variable amounts, or no active ingredient at all. Independent testing is required to verify identity and purity. Common analytical approaches include high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance for structural confirmation. These methods can distinguish GW501516 from related PPAR agonists and from unrelated steroids. For regulators and researchers, such verification is central to interpreting both biological results and adverse event reports.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
Anti-doping laboratories detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Visual description for typical solid reference material. |
| Solubility | Poorly soluble in water; soluble in DMSO | Solubility depends on solvent, purity, and form. |
| Storage | Cool, dry, protected from light | Long-term storage often uses low temperature and desiccant. |
| Common analytical method | LC-MS/MS | Used for detection and quantification in biological matrices. |
| Common synonyms | GW-501516; GW501516; endurobol | Naming varies among literature, vendors, and databases. |
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.
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.
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.
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.
Vitamin D is a group of structurally related, fat-soluble compounds responsible for increasing intestinal absorption of calcium, along with numerous other biological functions. In humans, the most important compounds within this group are vitamin D3 (cholecalciferol) and vitamin D2 (ergocalciferol). Unlike the other twelve vitamins, vitamin D is only conditionally essential in the diet, as with adequate skin exposure to the ultraviolet B (UVB) radiation component of sunlight there is synthesis of cholecalciferol in the deeper layers of the skin's epidermis. Vitamin D can also be obtained through diet, food fortification and dietary supplements. For most people, skin synthesis contributes more than dietary sources. Accordingly, the name "vitamin D" is arguably a misnomer, as rather than being an essential part of the diet, it acts more like a fat-soluble secosteroid hormone precursor. Nevertheless, US and other dietary guidelines generally assume that all of a person's vitamin D is taken orally, given the potential for insufficient sunlight exposure due to urban living, cultural choices for the amount of clothing worn when outdoors, and use of sunscreen because of concerns about safe sunlight exposure. In many countries, milk and plant-based milk substitutes are fortified with vitamin D3, as are breakfast cereals. Cholecalciferol is converted in the liver to calcifediol (also known as calcidiol or 25-hydroxycholecalciferol), while ergocalciferol is converted to ercalcidiol (25-hydroxyergocalciferol).
=== Coloration in mammals === The MC1R protein lies within the cell membrane, and is signalled by melanocyte-stimulating hormone (MSH) released by the pituitary gland. When activated by one of the variants of MSH, typically α-MSH, MC1R initiates a complex signaling cascade that leads to the production of eumelanin. In contrast, the receptor can also be antagonized by agouti signalling peptide (ASIP), which reverts the cell back to producing the yellow or red phaeomelanin. The yellow and black agouti banding pattern observed on most mammalian hair is caused by the pulsative nature of ASIP signalling through MC1R. Exceptions include particoloured bay horses, which have reddish bodies, and black legs, mane, and tail, where ASIP signaling is limited to regions instead of pulsating. Human hair, which is neither banded nor particoloured, is thought to be regulated by α-MSH signaling through MC1R exclusively. The prevalence of red hair in humans varies considerably worldwide. In the United States, about 25% of the human population carries the mutated melanocortin 1 receptor that causes red hair. With one in four people as carriers, the chance of two people having a child with red hair is about 2% (one in 64). People with freckles and no red hair have an 85% chance of carrying the MC1R gene that is connected to red hair. People with no freckles and no red hair have an 18% chance of carrying the MC1R gene linked to red hair. Eight genes have been identified in humans that control whether the MC1R gene is turned on and the person has red hair.
Turner spoke with Jesse Mulligan after two health workers in the United Kingdom had suffered allergic reactions to the COVID-19 vaccine early in December 2020, and noted that some reaction to any vaccine is always a possibility but "good quality services delivering vaccines" were crucial to deal with these reactions. She suggested people with very severe allergies did need to be careful and it was important good information about the strengths and limitations of this vaccine, based on clinical data that was appropriately scrutinized, was shared by the media, scientists and the general community . In December 2021, Medsafe gave provisional approval for the vaccine to be used for children in age group of 5 - 11 year-olds in New Zealand. Turner told Corin Dann on Radio New Zealand that initial internal clinical data from the use of the vaccine for children overseas had shown it was being rolled out well. She noted that it didn't need to be mandatory but would protect children with other health issues or living in poverty, would limit the spread of COVID-19 in families and have less impact on schools. Prior to this approval, Turner acknowledged there were "pros and cons" about children getting the vaccine, but a strong case could be made that this would be in the interests of protecting the community. Turner stated that the gap for New Zealand children to get their second dose of COVID-19 vaccine needed to be longer than that for adults and maintaining it at eight weeks was likely to result in better immunity.
The symptoms are mainly vomiting and diarrhea, and the condition may be misdiagnosed as gastroenteritis. Most potato poisoning victims recover fully, although fatalities are known, especially when victims are undernourished or do not receive suitable treatment. The United States National Institutes of Health's information on solanine strongly advises against eating potatoes that are green below the skin.
=== Pharmacokinetics === The metabolism of 4-HO-MET has been studied. In vitro experiments using pooled human liver microsomes identified twelve metabolites. Four metabolites were detected in vivo from human urine, of which two were detected in vitro.
Sources: en.wikipedia.org
2C drugs like 2C-I are metabolized by the monoamine oxidase (MAO) enzymes, including both MAO-A and MAO-B. As a result, 2C drugs may be potentiated by monoamine oxidase inhibitors (MAOIs), such as phenelzine, tranylcypromine, moclobemide, and selegiline. This has the potential to lead to overdose and serious toxicity. In contrast to 2C drugs, 25I-NBOMe has been found not to be metabolized by MAO-A or MAO-B and instead only by cytochrome P450 enzymes. Other 25-NB drugs besides 25I-NBOMe were not assessed.
He shared the Walter Knox Prize for Chemistry on Mill Hill School's Foundation Day, Friday, 7 July 1933. He declared that his success was founded on the quality of teaching he received whilst a pupil at Mill Hill. Crick studied at University College London (UCL), a constituent college of the University of London and earned a Bachelor of Science degree awarded by the University of London in 1937. Crick began a PhD at UCL, but was interrupted by World War II. He later became a PhD student and Honorary Fellow of Gonville and Caius College, Cambridge, and mainly worked at the Cavendish Laboratory and the Medical Research Council (MRC) Laboratory of Molecular Biology in Cambridge. He was also an Honorary Fellow of Churchill College, Cambridge, and of University College London. Crick began a PhD research project on measuring the viscosity of water at high temperatures (which he later described as "the dullest problem imaginable") in the laboratory of physicist Edward Neville da Costa Andrade at University College London, but with the outbreak of World War II (in particular, an incident during the Battle of Britain when a bomb fell through the roof of the laboratory and destroyed his experimental apparatus), Crick was deflected from a possible career in physics. During his second year as a PhD student, however, he was awarded the Carey Foster Research Prize, a great honour. He did postdoctoral work at the Brooklyn Collegiate and Polytechnic Institute, now part of the New York University Tandon School of Engineering.
April 27, 1999, A small fan site known as contaminated.net is relaunched as "Planet Half-Life", covering Half-Life and editing resources. November 16, 1999, Major changes to layout and color scheme, plus new sections covering Half-Life: Opposing Force and the announcement of Half-Life 2. December 3, 2000, New sections covering Counter-Strike and Team Fortress Classic. June 19, 2001, New section covering Half-Life: Blue Shift. September 14, 2002, New section covering Day of Defeat. May 24, 2003, Half-Life 2 section re-opens amid rumors of a September 2003 launch and early media releases. July 17, 2003, Major changes to color scheme and graphics in anticipation of Half-Life 2 launch. June 11, 2006, PHLWiki is launched, with bulk of content made up by staff writers prior to public unveiling. September 13, 2006, Complete site format change to accommodate new PNAP article submission system, as well as new color scheme and graphics that were used until the absence of site updating. September 13, 2007, PHL Steam Community officially announced to the public. August 13, 2012, Last entry posted.
In contrast to oral estradiol, due to the lack of the first pass, an excess in estrone and estrogen conjugate levels does not occur with transdermal estradiol or other parenteral estradiol routes. The transformation of estradiol into estrone and estrogen conjugates is reversible. As such, these metabolites can be converted back into estradiol. About 15% of orally administered estradiol is transformed into estrone and 65% into estrone sulfate. About 5% of estrone and 1.4% of estrone sulfate is converted back into estradiol. An additional 21% of estrone sulfate is converted into estrone, whereas transformation of estrone into estrone sulfate is approximately 54%. The interconversion between estradiol and estrone is mediated by 17β-hydroxysteroid dehydrogenases (17β-HSDs), whereas the conversion of estrone into estrone sulfate is mediated by estrogen sulfotransferases (ESTs) and the transformation of estrone sulfate into estrone by steroid sulfatase (STS). The metabolic clearance rates and hence blood half-lives of estrogen conjugates like estrone sulfate are much longer than those of estradiol and estrone. Estrogen conjugates, primarily estrone sulfate, serve as a large circulating reservoir for estradiol, and because of this, they function to greatly extend the biological half-life of oral estradiol. As such, the biological half-life of oral estradiol is a composite parameter that is dependent on interconversion between estradiol and estrogen conjugates, as well as on enterohepatic recirculation.
Sources: en.wikipedia.org
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.
Most methods use liquid chromatography with tandem mass spectrometry. Urine is common in anti-doping testing, and blood or plasma may be used in research.
Typical guidance is cool, dry, dark storage, often at low temperature and with desiccant. Stability data are limited, so storage conditions should be verified for each batch or supplier.
Legal status varies by country, but cardarine is not approved as a medicine in major jurisdictions. It is often sold as a research chemical, a category that may not be lawful for human use. Buyers should check local laws and product labels carefully.