A practical reference on clinical development: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-06-27 and is reviewed periodically as new material appears.
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.
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.
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.
| 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. |
Laboratory studies indicate that GW501516 activates PPARδ, a nuclear receptor involved in fatty acid oxidation and energy metabolism. In rodent experiments, treated animals often showed increased endurance and reduced fat mass. These effects were observed under controlled conditions and do not establish safe or effective use in humans. The exact dose-response relationship in humans remains poorly characterized. Species differences in metabolism can affect how results translate across animals and people.
Safety concerns emerged from long-term animal studies. In rodents given the compound for extended periods, researchers found an increased incidence of certain cancers, including liver and bladder tumors. These findings contributed to the discontinuation of clinical development. Whether similar risks apply to short-term or low-level exposure in humans is not established, and controlled human safety data are limited. The relevance of high-dose rodent carcinogenicity findings to human use remains a subject of debate.
Human trials of GW501516 were small and short in duration. They examined lipid levels, glucose handling, and other metabolic markers, but the programs were halted after the animal cancer findings. No approved therapeutic product exists, and published human data are insufficient for establishing long-term safety. Reports of use for athletic performance come mainly from non-clinical settings and cannot be verified through controlled trials. Independent testing of products sold as cardarine has found inconsistent purity and labeling.
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.
There are many different kinds of antibody and their production is highly complex, involving several types of lymphocyte, but in general lymphocytes and other antibody regulating and producing cells will migrate to the lymph nodes to aid in the release of these antibodies into the bloodstream. On the other hand, there are natural killer cells; these cells have the ability to take down threats that are larger in size, such as bacteria, parasites, and tumor cells. A separate study found that cortisol effectively disarmed natural killer cells, downregulating the expression of their natural cytotoxicity receptors. Prolactin has the opposite effect. It increases the expression of cytotoxicity receptors on natural killer cells, increasing their potency. Cortisol stimulates many copper enzymes (often to 50% of their total potential), including lysyl oxidase, an enzyme that cross-links collagen and elastin. Especially valuable for immune response is cortisol's stimulation of the superoxide dismutase, since this copper enzyme is almost certainly used by the body to permit superoxides to poison bacteria. Some viruses, such as influenza and SARS-CoV-1 and SARS-CoV-2, are known to suppress the secretion of stress hormones to avoid the organism's immune response. These viruses suppress cortisol by producing a protein that mimics the human ACTH hormone but is incomplete and does not have hormonal activity. ACTH is a hormone that stimulates the adrenal gland to produce cortisol and other steroid hormones.
=== Depression === A comparative meta-analysis of 21 major antidepressants found that venlafaxine, agomelatine, amitriptyline, escitalopram, mirtazapine, paroxetine, and vortioxetine were more effective than other antidepressants, although the quality of many comparisons was assessed as low or very low. Open-label evidence also suggests potential benefit in treatment-resistant cases: in a multicenter Canadian study of adults with inadequate response to prior antidepressants (n=159), 58% achieved response and 28% remission after 8 weeks of venlafaxine (mean 260 mg/day); tolerability was generally acceptable. Venlafaxine was similar in efficacy to the atypical antidepressant bupropion; however, the remission rate was lower for venlafaxine. In a double-blind study, patients who did not respond to an SSRI were switched to either venlafaxine or another SSRI (citalopram); similar improvement was observed in both groups. Studies have not established its efficacy for use in pediatric populations. In children and adolescents with depression, venlafaxine increases the risk of suicidal thoughts or attempts. Higher doses (e.g., 225 mg and 375 mg per day) of venlafaxine are more effective than lower doses (e.g., 75 mg per day) but also cause more side effects. Studies have shown that the extended-release is superior to the immediate-release form of venlafaxine. A 2017 meta-analysis has shown that the efficacy of venlafaxine is not correlated with baseline severity of depression.
== Mechanism of action == The mechanism seems to vary with different organisms and is not well understood. However, pentamidine is suspected to work through various methods of interference of critical functions in DNA, RNA, phospholipid and protein synthesis. Pentamidine binds to adenine-thymine-rich regions of the Trypanosoma parasite DNA, forming a cross-link between two adenines four to five base pairs apart. The drug also inhibits topoisomerase enzymes in the mitochondria of Pneumocystis jirovecii. Similarly, pentamidine inhibits type II topoisomerase in the mitochondria of the Trypanosoma parasite, resulting in a broken and unreadable mitochondrial genome.
provide an easy-to-use environment for individual application scientists themselves to create their own workflows, provide interactive tools for the scientists enabling them to execute their workflows and view their results in real-time, simplify the process of sharing and reusing workflows between the scientists, and enable scientists to track the provenance of the workflow execution results and the workflow creation steps. Some of the platforms giving this service: Galaxy, Kepler, Taverna, UGENE, Anduril, HIVE.
Sources: en.wikipedia.org
=== pH === The basic driving force for protein crystallization is to optimize the number of bonds one can form with another protein through intermolecular interactions. These interactions depend on electron densities of molecules and the protein side chains that change as a function of pH. The tertiary and quaternary structure of proteins are determined by intermolecular interactions between the amino acids' side groups, in which the hydrophilic groups are usually facing outwards to the solution to form a hydration shell to the solvent (water). As the pH changes, the charge on these polar side group also change with respect to the solution pH and the protein's pKa. Hence, the choice of pH is essential either to promote the formation of crystals where the bonding between molecules to each other is more favorable than with water molecules. pH is one of the most powerful manipulations that one can assign for the optimal crystallization condition.
Examples of drugs that can raise the serum potassium are non-selective beta-blockers such as propranolol and labetalol. Beta-1 selective blockers such as metoprolol do not increase serum potassium levels. Exercise can cause a release of potassium into the bloodstream by increasing the number of potassium channels in the cell membrane. The degree of potassium elevation varies with the degree of exercise, which ranges from 0.3 meq/L in light exercise to 2 meq/L in heavy exercise, with or without accompanying ECG changes or lactic acidosis. However, peak potassium levels can be reduced by prior physical conditioning, and potassium levels are usually reversed several minutes after exercise. High levels of adrenaline and noradrenaline have a protective effect on the cardiac electrophysiology because they bind to beta 2 adrenergic receptors, which, when activated, extracellularly decrease potassium concentration. Hyperkalemic periodic paralysis is an autosomal dominant clinical condition where there is a mutation in the gene located at 17q23 that regulates the production of protein SCN4A. SCN4A is an important component of sodium channels in skeletal muscles. During exercise, sodium channels normally open to allow the influx of sodium into the muscle cells for depolarization to occur. But in hyperkalemic periodic paralysis, sodium channels are slow to close after exercise, causing excessive influx of sodium and displacement of potassium out of the cells. Rare causes of hyperkalemia are discussed as follows.
The contact activation pathway begins with formation of the primary complex on collagen by high-molecular-weight kininogen (HMWK), prekallikrein, and FXII (Hageman factor). Prekallikrein is converted to kallikrein and FXII becomes FXIIa. FXIIa converts FXI into FXIa. Factor XIa activates FIX, which with its co-factor FVIIIa form the tenase complex, which activates FX to FXa. The minor role that the contact activation pathway has in initiating blood clot formation (or more specifically, physiological hemostasis) can be illustrated by the fact that individuals with severe deficiencies of FXII, HMWK, and prekallikrein do not have a bleeding disorder. Instead, contact activation system seems to be more involved in inflammation, and innate immunity. Interference with the pathway may confer protection against thrombosis without a significant bleeding risk. Inhibition of factor XII and PK interferes with innate immunity in animal models. More promising is inhibition of factor XI, which in early clinical trials have shown the expected effect.
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.
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.