This is a working overview of metabolite, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-03-21 and is reviewed periodically as new material appears.
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.
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.
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 |
|---|---|---|
| Regulatory status | Prohibited in sport; not approved as medicine | Listed by WADA at all times. |
| Common synonyms | GW501516, GW-501516, endurobol | Cardarine is a colloquial name. |
| Typical analytical method | LC-MS/MS | Detects parent compound and metabolites. |
| Common test matrix | Urine | Blood and dried blood spots also possible. |
| Legal classification | Varies by country | Often treated as unapproved drug or research chemical. |
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.
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.
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.
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.
== Medical uses == Oxymetazoline is available over-the-counter as a topical decongestant in the form of oxymetazoline hydrochloride in nasal sprays. Due to its vasoconstricting properties, oxymetazoline is also used to treat nosebleeds and eye redness due to minor irritation (marketed as Visine L.R. in the form of eye drops). In the United States, oxymetazoline 1% cream was approved by the Food and Drug Administration (FDA) in January 2017 for topical treatment of persistent facial erythema (redness) associated with rosacea in adults. In July 2020, oxymetazoline received approval by the FDA for the treatment of acquired blepharoptosis (drooping eyelid).
=== Food quality === Decontamination of food by ionizing radiation is a safe and efficient process for elimination of pathogenic bacteria. Ionizing radiation treatment can be applied to either raw materials or ready to eat foods, with some countries, like the United States, imposing limitations on its use. Assessed rigorously over several decades, irradiation in commercial amounts to treat food has no negative impact on the sensory qualities and nutrient content of foods.
Vulture bees are a small group of obligately necrophagous bees in the Trigona genus. Trigona worker bees play a similar role to worker bees in the Apis genus; however, along with collecting pollen, nectar, and plant resins, Trigona workers also collect carrion. Although pollen is associated with higher energy value, carrion is preferred by Trigona bees because it is biochemically easier to extract energy from. This dead animal tissue is used as a source of amino acids too. Cerumen pots are utilized by some Trigona species, such as T. necrophaga, as vesicles to store foodstuff. The foodstuff of T. necrophaga consists of both honey and carrion from vertebrate carcasses. Ultimately, the stored food is utilized by developing larvae and the worker bee itself as a source of nutrition and energy. Due to the rapid decomposition of carrion, especially in warm temperatures, the bees must efficiently metabolize the carrion to avoid rotten carrion in their cerumen pots. Trigona hypogea communicate the presence of a valuable carcass through olfactory signals. The bees create an odour trail between their nest and the prospective animal carcass; thus, the bees recruit the other nest members to respond and exploit the corpse's resources rapidly. Additionally, interspecific competition is observed in Trigona hypogea bees. The bees are observed to defend their colonized food item, including but not limited to a monkey, lizard, fish, or snake carcass, from competing necrophages, such as flies.
==== Neuromuscular fatigue ==== Nerves control the contraction of muscles by determining the number, sequence, and force of muscular contraction. When a nerve experiences synaptic fatigue it becomes unable to stimulate the muscle that it innervates. Most movements require a force far below what a muscle could potentially generate, and barring pathology, neuromuscular fatigue is seldom an issue. For extremely powerful contractions that are close to the upper limit of a muscle's ability to generate force, neuromuscular fatigue can become a limiting factor in untrained individuals. In novice strength trainers, the muscle's ability to generate force is most strongly limited by nerve's ability to sustain a high-frequency signal. After an extended period of maximum contraction, the nerve's signal reduces in frequency and the force generated by the contraction diminishes. There is no sensation of pain or discomfort, the muscle appears to simply 'stop listening' and gradually cease to move, often lengthening. As there is insufficient stress on the muscles and tendons, there will often be no delayed onset muscle soreness following the workout. Part of the process of strength training is increasing the nerve's ability to generate sustained, high frequency signals which allow a muscle to contract with their greatest force. It is this "neural training" that causes several weeks worth of rapid gains in strength, which level off once the nerve is generating maximum contractions and the muscle reaches its physiological limit.
Nicotinamide mononucleotide adenylyltransferase 2 (NMNAT2) is an enzyme that in humans is encoded by the NMNAT2 gene. This gene product belongs to the nicotinamide-nucleotide adenylyltransferase (NMNAT) enzyme family, members of which catalyze an essential step in the nicotinamide adenine dinucleotide (NAD+ (NADP)) biosynthetic pathway. NMNAT2 is cytoplasmic (associated with the Golgi apparatus), and is predominantly expressed in the brain. Two transcript variants encoding different isoforms have been found for this gene.
Sources: en.wikipedia.org
=== Protein complex purification === Complexes of interacting proteins may also be purified using the SBP-Tag because elution with biotin permits recovery under conditions in which desired complexes remain associated. For example, the Condensin Complex was purified by Kim et al. [2010] and complexes with the TAZ transcriptional co-activator were purified by Zhang et al. [2009]. The SBP-Tag has also been incorporated into several Tandem Affinity Purification (TAP) systems in which successive purification steps are utilized with multiple tags, for example GFP fusion proteins and BTK-protein complexes were purified using a TAP protocol with the SBP-Tag and the His-Tag, HDGF-protein complexes were purified using a TAP protocol with the SBP-Tag and with the FLAG-tag and Wnt complexes were purified using a TAP protocol with the SBP-Tag and with the [Calmodulin-Tag]. TAP is generally used with protein complexes and several studies report significant improvements in purity and yield when the SBP-Tag TAP systems are compared to non-SBP-Tag systems. Commercial TAP systems that use the SBP-Tag include the Interplay® Adenoviral and Mammalian TAP Systems sold by Agilent Technologies, similar products are sold by Sigma-Aldrich.
express the short-range order of the liquid, i.e., the correlations between a molecule and "shells" of nearest neighbors, next-nearest neighbors, and so on. An equivalent representation of these correlations is the radial distribution function
== Research == CPA has been studied and used in combination with low-dose diethylstilbestrol in the treatment of prostate cancer. The combination results in suppression of testosterone levels into the castrate range, which normally cannot be achieved with CPA alone. CPA has been studied as a form of androgen deprivation therapy for the treatment of benign prostatic hyperplasia (enlarged prostate). The medication has been studied in the treatment of breast cancer as well. CPA has been studied for use as a potential male hormonal contraceptive both alone and in combination with testosterone in men. CPA was under development by Barr Pharmaceuticals in the 2000s for the treatment of hot flashes in prostate cancer patients in the United States. It reached phase III clinical trials for this indication and had the tentative brand name CyPat but development was ultimately discontinued in 2008. CPA is not satisfactorily effective as topical antiandrogen, for instance in the treatment of acne. CPA has been used to treat estrogen hypersensitivity vulvovaginitis in women. CPA has been investigated for use in reducing aggression and self-injurious behavior via its antiandrogenic effects in conditions like autism spectrum disorders, dementias like Alzheimer's disease, and psychosis. CPA may be effective in the treatment of obsessive–compulsive disorder (OCD). CPA has been studied in the treatment of cluster headaches in men.
=== Lupus === As of 2016, studies in cells, animals, and humans have suggested that mTOR activation is a process underlying systemic lupus erythematosus and that inhibiting mTOR with rapamycin may be a disease-modifying treatment. As of 2016 rapamycin had been tested in small clinical trials in people with lupus.
Sources: en.wikipedia.org
In October 2025, Pritzker and the Illinois Department of Transportation announced a proposed six-year Highway & Multimodal Multi-Year Improvement Program, slated to begin in fiscal year 2026, involving the leveraging of $50.6 billion in public funds to invest $32.5 billion into more than 7,100 miles of state and local roads and 8.4 million square feet of bridge deck, $13.8 billion distributed across 90 transit projects, $2.9 billion for 29 freight and passenger rail projects, $1.2 billion for 244 aviation projects, and $200 million for ports and waterways, including 28 marine projects. The plan includes $388 million for the proposed Quad Cities Amtrak route between Chicago and Moline, Illinois and $400 million to replace the I-80 bridge that connects LeClaire, Iowa, and Rapids City, Illinois. In June 2019, Pritzker deployed 200 Illinois National Guardsmen to combat flooding across central and southern Illinois. The troops were tasked with sandbagging, protecting levees and keeping evacuation routes open. In August 2019, he officially requested a federal disaster declaration for 32 Illinois counties due to flooding since February 2019. The request came after the state's disaster assessment was concluded.
First proposed in 1972 by Meldner, such a reaction might enable the production of macroscopic quantities of superheavy elements within the island of stability; the role of fission in intermediate superheavy nuclides is highly uncertain, and may strongly influence the yield of such a reaction.
==== Immunotherapy ==== Immunotherapy successfully treats some kinds of cancer, such as melanoma. This treatment involves manipulating a human's immune system to destroy cancerous cells. Humans have two major antigen identifying lymphocytes: CD8+ cytotoxic T-lymphocytes (CTL) and CD4+ helper T-lymphocytes that can destroy cells. Antigen receptors on CTL can bind to a 9–10 amino acid chain that is presented by the major histocompatibility complex (MHC) as in Figure 4. HTERT is a potential target antigen. Immunotargeting should result in relatively few side effects since hTERT expression is associated only with telomerase and is not essential in almost all somatic cells. GV1001 uses this pathway. Experimental drug and vaccine therapies targeting active telomerase have been tested in mouse models, and clinical trials have begun. One drug, imetelstat, is being clinically researched as a means of interfering with telomerase in cancer cells. Most of the harmful cancer-related effects of telomerase are dependent on an intact RNA template. Cancer stem cells that use an alternative method of telomere maintenance are still killed when telomerase's RNA template is blocked or damaged.
Sources: en.wikipedia.org
Legal status varies by country. It is not approved as a medicine, and it is prohibited in sport. Some jurisdictions restrict import, sale, or possession.
Laboratories use liquid chromatography-tandem mass spectrometry to detect GW501516 and its metabolites. Urine is commonly tested, and testing can occur in and out of competition.
No, cardarine is not a SARM. It is a PPARδ agonist, which acts on a different receptor. The two classes are often confused in online discussions.
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.