This is a working overview of Metabolic modulator, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-27. Anything still debated is marked as such rather than presented as settled.
Quality assessment for cardarine samples usually combines identity, purity, and impurity testing. Nuclear magnetic resonance spectroscopy and mass spectrometry can confirm molecular structure, while high-performance liquid chromatography estimates purity. Certificates of analysis from testing laboratories may list these results, but they do not establish safety or legality. In the absence of approved manufacturing, products sold online may contain the wrong compound, variable amounts, or unlisted contaminants. Independent verification is therefore central to analytical work and to interpreting any reported biological activity.
Laboratory detection of GW501516 commonly uses liquid chromatography coupled with tandem mass spectrometry. The method can identify the parent compound or its metabolites in urine and blood after sample cleanup. Protein precipitation, solid-phase extraction, or enzymatic hydrolysis may precede analysis, depending on the matrix. Reference standards are required for accurate quantification and confirmation. Because the compound is not approved, testing often occurs in anti-doping, forensic, or research settings rather than routine clinical care. Results are reported with limits of detection and quantification.
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.
Sporting authorities added GW501516 to prohibited lists after it appeared in athlete samples and online markets. The World Anti-Doping Agency classifies it as a hormone and metabolic modulator, and its use can lead to an anti-doping rule violation. Some early laboratory work suggested effects on fatty acid oxidation and endurance-related metabolism in animals, but those findings do not establish safe or effective use in people. Reports of adverse events in humans are scarce and often anecdotal, which complicates risk assessment.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Common for reference-grade material. |
| Solubility | Low in water | Dissolves in DMSO and some organic solvents. |
| Typical storage | -20 °C, desiccated | Protect from light and moisture. |
| Analytical method | LC-MS/MS | Used for trace detection in biological matrices. |
| Purity assessment | HPLC with UV detection | Often combined with NMR and mass spectrometry. |
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.
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.
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.
Anti-doping laboratories identify GW501516 and related metabolites using liquid chromatography coupled with tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be analyzed. The method targets the parent compound and phase I and phase II metabolites, which extend the detection window. Because the substance is prohibited at all times, athletes can be tested outside competition. Detection limits and windows depend on the assay, sample type, and individual metabolism.
Regulatory treatment varies, but cardarine is not approved as a medicine. Sports authorities list GW501516 as a prohibited substance, and it is banned at all times under the World Anti-Doping Agency code. Many countries restrict sales for human consumption, while online vendors market it as a research chemical. Such products may lack purity data, and their actual contents can differ from the label. Purchasing or possessing cardarine may carry legal consequences depending on jurisdiction. The compound is not a dietary supplement ingredient in regulated markets.
Clinical development stopped after rodent studies showed tumors at multiple sites. Whether those findings predict human cancer risk remains an open question, but they led sponsors to discontinue programs. Human safety data are limited to small, short-term studies that were not designed to assess cancer risk. Reported effects in those studies included changes in blood lipids, but the evidence is insufficient for medical use. Long-term consequences of nonmedical use are not well characterized. Questions about dose, duration, and individual susceptibility remain unresolved.
Cardarine is a common name for GW501516, an investigational compound developed in the 1990s for metabolic conditions. It acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in lipid and energy metabolism. The compound is frequently mislabeled as a selective androgen receptor modulator, or SARM, but its molecular target is different. GW501516 reached early clinical testing before development was discontinued. It has no approved therapeutic use in any country. The name cardarine is not a formal international nonproprietary name.
β turns (also β-bends, tight turns, reverse turns, Venkatachalam turns) are the most common form of turns—a type of non-regular secondary structure in proteins that cause a change in direction of the polypeptide chain. They are very common motifs in proteins and polypeptides. Each consists of four amino acid residues (labelled i, i+1, i+2 and i+3). They can be defined in two ways:
=== Honors and awards === On December 4, 2015, Sanders won Time's 2015 Person of the Year readers' poll with 10.2% of the vote but did not receive the editorial board's award. On March 20, 2016, he was given an honorary Lushootseed name, dxʷshudičup, by Deborah Parker in Seattle to honor his focus on Native American issues during his presidential campaign. On May 30, 2017, Sanders received an honorary degree of Doctor of Humane Letters from Brooklyn College.
== External links == Clegg, Simon. "Surface tension calculator for aqueous solutions". www.aim.env.uea.ac.uk. University of East Anglia. Retrieved 26 August 2026. Clegg, Simon. "Densities of H+ - NH+4 - Na+ - SO2−4 - NO−3 - Cl− - H2O". www.aim.env.uea.ac.uk. University of East Anglia. Retrieved 26 August 2026.
==== Oxidation of biomass ==== Formic acid can also be obtained by aqueous catalytic partial oxidation of wet biomass by the OxFA process. A Keggin-type polyoxometalate (H5PV2Mo10O40) is used as the homogeneous catalyst to convert sugars, wood, waste paper, or cyanobacteria to formic acid and CO2 as the sole byproduct. Yields of up to 53% formic acid can be achieved.
== Structure == The phytaspase displays a structure, common to the subtilisin-like proteases. Its N-terminus includes a prodomain, which commonly inhibits subtilisin-like proteases and undergoes an autocatalytic cleavage during maturation, followed by a protease domain, which includes and adheres the common order of the sequence of the three canonic catalytic amino acid residues, and a prolonged C-terminal domain.
Sources: en.wikipedia.org
==== United States ==== 3,4-DMA is not an explicitly controlled substance in the United States, but can be considered a Schedule I controlled substance as a positional isomer of 2,5-dimethoxyamphetamine (2,5-DMA) in this country.
== Further reading == Booth, Martin (2004). Cannabis: A History. Picador. ISBN 978-0-312-42494-7. Drake, Bill (2002). The Marijuana Food Handbook: A Guide for the Sensuous Connoisseur. Ronin Publishing. ISBN 978-0-914171-99-7. Grinspoon, Lester (1994). Marihuana Reconsidered. Quick American Archives. ISBN 978-0-932551-13-9.
== Flexible design == The functional group, the spacer and the lipid tail components of the FSL Kode construct can each be individually designed resulting in FSL Kode constructs with specific biological functions. The functional head group is usually the bioactive component of the construct and the various spacers and lipids influence and effect its presentation, orientation and location on a surface. Critical to the definition of an FSL Kode construct is the requirement to be dispersible in water, and spontaneously and stably incorporate into cell membranes. Other lipid bioconjugates that include components similar to FSLs but do not have these features are not termed as Function-Spacer-Lipid Kode constructs.
==== United States ==== JRT is not an explicitly controlled substance in the United States. However, it could be considered a controlled substance under the Federal Analogue Act if intended for human consumption.
In 1999, initiated by the International Olympic Committee to fight against doping in sport, the World Anti-Doping Agency had been founded. After the doping scandal in cycling in the summer 1998 the International Olympic Committee (IOC) decided to establish the WADA to promote, coordinate and monitor the fight of against doping in sport. The headquarters for WADA is in Montreal, Canada. The WADA is the supreme international authority and is allowed to do doping tests and can determine which substances are illegal. In February 2011, the United States Olympic Committee and the Ad Council launched an anti-steroid campaign called Play Asterisk Free aimed at teens. The campaign first launched in 2008 under the name "Don't Be An Asterisk!". In October 2012, the USADA released evidence to corroborate their doping claim against cyclist Lance Armstrong. According to USADA CEO Travis T. Tygart, the evidence against Armstrong includes, "...scientific data and laboratory test results that further prove the use, possession and distribution of performance-enhancing drugs". On 1 November 1989, US Senator Joseph Biden introduced S. 1829, The Steroid Trafficking Act of 1989. The purpose of the act was simple: It would "amend the Controlled Substances Act to further restrict the use of steroids. By designating anabolic steroids as a Schedule II controlled substance, the bill would crack down on illegal steroid use". (Senate Judiciary Committee, 2002, p. 282).
Sources: en.wikipedia.org
He concluded his speech by saying that "great rejuvenation of the Chinese nation and making America great again can go hand in hand" and that "Let us meet the people's expectations and show our historical initiative, let us keep advancing the cause of friendship between our two peoples and work together to build a better world".
Vacutainer tubes may contain additional substances that preserve blood for processing in a medical laboratory. Using the wrong tube may make the blood sample unusable for the intended purpose. These additives are typically thin film coatings applied using an ultrasonic nozzle. The additives may include anticoagulants (EDTA, sodium citrate, heparin) or a gel with density between those of blood cells and blood plasma. Additionally, some tubes contain additives that preserve certain components of or substances within the blood, such as glucose. When a tube is centrifuged, the materials within are separated by density, with the blood cells sinking to the bottom and the plasma or serum accumulating at the top. Tubes containing gel can be easily handled and transported after centrifugation without the blood cells and serum mixing.
=== Other branches === Biotechnology, Bioluminescence, Molecular chemistry, Enzymatic chemistry, Genetic engineering, Pharmaceuticals, Endocrinology, Neurochemistry, Hematology, Nutrition, Photosynthesis, Environmental, Toxicology, Structural biology
== Clinical research == The feasibility of using recombinant human tropoelastin to promote elastin-fibre production and improve skin flexibility in wounds and scars has been studied. Although new elastin fibres were observed following the administration of recombinant human tropoelastin into fresh wounds, the treatment did not result in significant improvements in scar appearance or flexibility. Another line of research has investigated stimulation of endogenous elastin production in the skin. In an in vitro study, an amino acid–copper mixture increased elastin- and type I collagen-related gene expression and protein production in cultured human dermal fibroblasts compared with copper or the amino acid mixture alone. A subsequent open-label, single-centre clinical study evaluated a skin-booster formulation containing amino acids, copper sulfate and non-cross-linked hyaluronic acid, marketed as Elastic Lab. Five participants received four facial treatments at one-week intervals, and the outcomes were assessed one week after the final treatment. Instrumentally measured skin elasticity increased by 23.4% from baseline, while skin thickness and density increased by 7.3% and 12.5%, respectively. Improvements in skin hydration and periocular wrinkle depth were also reported. The study did not directly measure newly synthesised or deposited elastin fibres.
while fresh citrus (particularly lemons) cured scurvy, lime juice that had been exposed to light, air, and copper tubing did not – thus undermining the theory that citrus cured scurvy; fresh meat (especially organ meat and raw meat, consumed in arctic exploration) also cured scurvy, undermining the theory that fresh vegetable matter was essential to preventing and curing scurvy; increased marine speed via steam shipping, improved nutrition on land, reduced the incidence of scurvy – and thus the ineffectiveness of copper-piped lime juice compared to fresh lemons was not immediately revealed. In the resulting confusion, a new hypothesis was proposed, following the new germ theory of disease – that scurvy was caused by ptomaine, a waste product of bacteria, particularly in tainted tinned meat. Infantile scurvy emerged in the late 19th century because children were fed pasteurized cow's milk, particularly in the urban upper class. While pasteurization killed bacteria, it also destroyed vitamin C. This was eventually resolved by supplementing with onion juice or cooked potatoes. Native Americans helped save some newcomers from scurvy by directing them to eat wild onions.
Sources: en.wikipedia.org
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.
Reference material is usually kept cold, dry, and protected from light. Frozen aliquots reduce repeated freeze-thaw cycles.
No approved pharmaceutical product exists, so manufacturing and quality controls are not standardized. Products may contain different compounds or impurities.
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.