If you have been reading about Reference standard and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-07-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
Analytical laboratories typically identify cardarine and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is a common matrix in anti-doping testing, while blood and tissue may be used in research settings. Detection windows depend on the assay, the sample matrix, and the compound's metabolism. Because cardarine is extensively metabolized, laboratories often target specific metabolites to improve sensitivity and confirmation. Reference standards are required for reliable quantification. Method validation includes checks for selectivity, linearity, and carryover.
A persistent misconception is that cardarine is a fat-burning drug or a safe alternative to anabolic steroids. No approved therapeutic product exists, and human safety data are limited. The tumor findings in rodents remain a central concern in scientific reviews. Products sold online may contain inaccurate labels, impurities, or different compounds entirely, which complicates any assessment of effects. Independent testing of such products has reported frequent mislabeling. For these reasons, discussions in the literature emphasize risks and unknowns rather than benefits.
Cardarine is not approved for human therapeutic use in any major jurisdiction. It appears on the World Anti-Doping Agency Prohibited List as a PPARδ agonist within the hormone and metabolic modulators category. Sports organizations test for it because it has been detected in athlete samples and seized products. Regulatory actions against marketed research chemical versions have occurred in several countries, though enforcement varies. Availability through unregulated channels complicates oversight.
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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved for human therapeutic use | No marketing authorization identified in major jurisdictions. |
| Anti-doping class | PPARδ agonist; hormone and metabolic modulators | Listed on the WADA Prohibited List. |
| Common test matrix | Urine | Also blood and tissue in research settings. |
| Typical analytical method | LC-MS/MS | Targets parent compound and metabolites. |
| Major safety signal | Tumor findings in rodents | Human relevance not established; limited human data. |
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.
A common misconception is that cardarine has been proven safe for human use. In reality, human clinical data are limited, and long-term animal studies have raised concerns about cancer. Another misconception is that it is a supplement or vitamin-like compound. It is a synthetic research chemical with no approved medical indication. Scientific discussion often focuses on its mechanism and detection rather than therapeutic use. Regulatory and anti-doping literature treats it primarily as a prohibited substance.
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.
Cardarine is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a drug.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
Stability of GW501516 depends on form, temperature, light exposure, and moisture. Solid reference material is typically stored frozen or refrigerated in a desiccator and protected from light. Solutions in organic solvents such as dimethyl sulfoxide are often kept frozen in aliquots to reduce freeze-thaw cycling. Aqueous solubility is low, so aqueous stock solutions can be difficult to prepare without cosolvents. Degradation may appear as changes in chromatographic purity or mass spectral signal. Stability studies are needed to establish shelf life for any specific preparation.
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.
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.
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.
AMP deaminase deficiency (formally known as myoadenylate deaminase deficiency or MADD) is a metabolic myopathy which results in excessive AMP buildup brought on by exercise. AMP deaminase is needed to convert AMP into IMP in the purine nucleotide cycle. Without this enzyme, the excessive AMP buildup is initially due to the adenylate kinase (myokinase) reaction which occurs after a muscle contraction. However, AMP is also used to allosterically regulate the enzyme myophosphorylase (see Glycogen phosphorylase § Regulation), so the initial buildup of AMP triggers the enzyme myophosphorylase to release muscle glycogen into glucose-1-P (glycogen→glucose-1-P), which eventually depletes the muscle glycogen, which in turn triggers protein metabolism, which then produces even more AMP. In AMP deaminase deficiency, excess adenosine is converted into uric acid in the following reaction:
osmotic concentration maintained by the use of metabolically inert substances like lactobionate and raffinose rather than with glucose Hydroxyethyl starch (HES) is used to prevent edema Substances are added to scavenge free radicals, along with steroids and insulin.
=== Internal factors === Internal factors causing necrosis include: trophoneurotic disorders (diseases that occur due to defective nerve action in a part of an organ which results in failure of nutrition); injury and paralysis of nerve cells. Pancreatic enzymes (lipases) are the major cause of fat necrosis. Necrosis can be activated by components of the immune system, such as the complement system; bacterial toxins; activated natural killer cells; and peritoneal macrophages. Pathogen-induced necrosis programs in cells with immunological barriers (intestinal mucosa) may alleviate invasion of pathogens through surfaces affected by inflammation. Toxins and pathogens may cause necrosis; toxins such as snake venoms may inhibit enzymes and cause cell death. Necrotic wounds have also resulted from the stings of Vespa mandarinia. Pathological conditions are characterized by inadequate secretion of cytokines. Nitric oxide (NO) and reactive oxygen species (ROS) are also accompanied by intense necrotic death of cells. A classic example of a necrotic condition is ischemia which leads to a drastic depletion of oxygen, glucose, and other trophic factors and induces massive necrotic death of endothelial cells and non-proliferating cells of surrounding tissues (neurons, cardiomyocytes, renal cells, etc.). Recent cytological data indicates that necrotic death occurs not only during pathological events but it is also a component of some physiological process.
Sources: en.wikipedia.org
== Common mass spectrometer configurations and techniques == When a specific combination of source, analyzer, and detector becomes conventional in practice, a compound acronym may arise to designate it succinctly. One example is MALDI-TOF, which refers to a combination of a matrix-assisted laser desorption/ionization source with a time-of-flight mass analyzer. Other examples include inductively coupled plasma-mass spectrometry (ICP-MS), accelerator mass spectrometry, thermal ionization-mass spectrometry (TIMS) and spark source mass spectrometry. Certain applications of mass spectrometry have developed monikers that although strictly speaking would seem to refer to a broad application, in practice have come instead to connote a specific or a limited number of instrument configurations. An example of this is isotope-ratio mass spectrometry, which refers in practice to the use of a limited number of sector based mass analyzers; this name is used to refer to both the application and the instrument used for the application.
The Tanukhids were Christianised in the 3rd or 4th centuries, likely while in the eastern half of the Fertile Crescent, and by the 4th century they were described as having a "fanatic zeal for Christianity" and were "zealous Christian soldiers" in the 6th century. In the 7th century, during the Muslim conquest of the Levant, the Tanukhids fought with the Romans against the Muslims, including in the Battle of Yarmouk. After Yarmouk, their status as foederati ended. They were described as an "autonomous Christian community in Bilad al-Sham" up until the reign of the Abbasid caliph al-Mahdi (r. 775–785), after which they appear as Muslims. Their conversion to Islam is believed to have been forced upon them by al-Mahdi. They are reported to have been devoted to Christianity, Thomas the Apostle and monasticism, with many monasteries associated with the tribe. Epistle 50, one of the Epistles of Wisdom composed by Druze missionaries in the early 11th century, was explicitly directed to three Tanukhid emirs settled in the mountainous Gharb area southeast of Beirut, calling on them to continue the tradition of their ancestors in spreading Druze teachings. The Gharb was less rugged than the neighboring areas to the north and south, and its strategic value stemmed from its control of Beirut's southern harbor and the road connecting Beirut with Damascus. The warrior peasants who inhabited the Gharb subscribed to the Druze faith, an esoteric offshoot of Isma'ili Shia Islam, the religion of the Fatimid caliphs of Egypt.
A unique membrane-bound prokaryotic organelle, the magnetosome has been discovered in magnetotactic bacteria. Cells were discovered by Robert Hooke in 1665, who named them after their resemblance to cells in a monastery. Cell theory, developed in 1839 by Matthias Jakob Schleiden and Theodor Schwann, states that all organisms are composed of one or more cells, that cells are the fundamental unit of structure and function in all organisms, and that all cells come from pre-existing cells.
== References == Church, I.J. & Parsons, A.L.: (1995) Modified Atmosphere Packaging Technology: A Review, Journal Science Food Agriculture, 67, 143-152 Day, B.P.F.: (1996) A perspective of modified atmosphere packaging of fresh produce In Western Europe, Food Science and Technology Today, 4,215-221 European Food Information Council (EFIC: (2001) Opinion of the Scientific Committee on Food on the use of carbon monoxide as component of packaging gases in modified atmosphere packaging for fresh meat. Parry, R. T.: (1993) Principles and applications of MAP of foods, Blackie Academic & Professional, England, 1-132 Phillips, C.A.: (1996) Review: Modified Atmosphere Packaging and its effects on the microbial quality and safety of produce, International Journal of Food Science and Tech, 31, 463-479 Robertson, G. L., "Food Packaging: Principles and Practice", 3rd edition, 2013, ISBN 978-1-4398-6241-4 Zagory, D. & Kader, A.A.: (1988) Modified atmosphere packaging of fresh produce, Food Technology., 42(9), 70-77
Sources: en.wikipedia.org
== Context == Leonard P. Guarente is recognized as the leading proponent of the hypothesis that caloric restriction slows aging by activation of Sirtuins. STACs have been discovered by Konrad Howitz of Biomol Inc and biologist David Sinclair. In September 2003, Howitz and Sinclair et al. published a highly cited paper reporting that polyphenols such as resveratrol activate human SIRT1 and extend the lifespan of budding yeast (Howitz et al., Nature, 2003). Other examples of such products are butein, piceatannol, isoliquiritigenin, fisetin, and quercetin. Sirtuins depend on the crucial cellular molecule called nicotinamide adenine dinucleotide (NAD+) for their function. Falling NAD+ levels during aging may adversely impact sirtuin maintenance of DNA integrity and ability to combat oxidative stress-induced cell damage. Increasing cellular NAD+ levels with supplements like nicotinamide mononucleotide (NMN) during aging may slow or reverse certain aging processes with sirtuin function enhancement. Some STACs can cause artificial effects in the assay initially used for their identification, but it has been shown that STACs also activate SIRT1 against regular polypeptide substrates, with an influence of the substrate sequence. Sirtris Pharmaceuticals, Sinclair's company, was purchased by GlaxoSmithKline (GSK) in 2008, and subsequently shut down as a separate entity within GSK.
DPP-4 inhibitors usually have an electrophilic group that can interact with the hydroxyl of the catalytic serine in the active binding site (Figure 3). Frequently that group is a nitrile group but can also be boronic acid or diphenyl phosphonate. This electrophilic group can bind to the imidate complex with covalent bonds and slow, tight-binding kinetics but this group is also responsible for stability issues due to reactions with the free amino group of the P2-amino acid. Therefore, inhibitors without the electrophilic group have also been developed, but these molecules have shown toxicity due to affinity to other dipeptidyl peptidases, e.g. DPP-2, DPP-8 and DPP-9. DPP-4 inhibitors span diverse structural types. In 2007 few of the most potent compounds contain a proline mimetic cyanopyrrolidine P1 group. This group enhances the potency, probably due to a transient covalent trapping of the nitrile group by the active site Ser630 hydroxyl, leading to delayed dissociation and slow tight binding of certain inhibitors. When these potency enhancements were achieved, some chemical stability issues were noted and more advanced molecules had to be made. To avoid these stability issues, the possibility to exclude the nitrile group was investigated. Amino acids with aryl or polar side chains did not show appreciable DPP-4 inhibition and in fact, all compounds without the nitrile group in this research suffered a 20 to 50-fold loss of potency corresponding to the compounds containing the nitrile group.
=== Cancer research === For hundreds of years, S. mutilans was used in traditional Chinese medicine for cancer treatment and other curative effects. Arthropod medicines were found to have a high level of antitumour effect in modern studies, and centipede is one of the major constituents of such medication. Extraction from these centipedes was found to be effective in controlling the proliferation of HepG2 cells (liver cancer). The mechanism by which the centipede extract alleviates liver cancer is related to the regulation of PI3/AKT, STA3, and MAPK signalling pathways. Water extracts from the dried whole body of this species were reported to have antitumour properties, and would lead to enhanced immune responses. SPPC is a polysaccharide-protein complex that can be extracted from the centipede by pouring hot water over the powdered, dried body of the organism. In mice clinical trials, SPPC was found to effectively suppress the growth of S180 cancer cell in mice by promoting both specific and nonspecific immune responses. H22-bearing mice were found to have extended survival time with the administration of SPPC.
Sources: en.wikipedia.org
No. Cardarine has not received approval for human therapeutic use in major jurisdictions. It remains an investigational compound.
It is classified as a PPARδ agonist on the WADA Prohibited List. Anti-doping laboratories can detect it and its metabolites in urine. Its use is banned in competition and usually out of competition.
Rodent studies reported increased tumor incidence at multiple sites. The human relevance remains uncertain, but the findings contributed to discontinuation of development. No long-term human cancer data are available.
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.