GW501516 comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2025-09-19. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
| 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. |
Regulatory treatment of cardarine differs by context and jurisdiction. In competitive sport, the World Anti-Doping Agency lists PPARδ agonists, including GW501516, as prohibited at all times. Outside sport, it lacks approval as a prescription medicine in major drug markets, and products sold for human consumption may be treated as unapproved drugs. Some countries also restrict importation or sale through general consumer protection and medicines laws. These classifications affect availability, testing, and legal risk without establishing therapeutic value.
Because cardarine is not an approved medicine, no pharmacopeial monograph defines its identity, purity, or storage requirements. Laboratories typically rely on in-house methods and reference standards when testing materials labeled as GW501516. Certificates of analysis may report purity and identity for a specific batch, but their scope varies and they do not guarantee safety or legal status. Independent verification can include high-performance liquid chromatography, mass spectrometry, nuclear magnetic resonance, and elemental analysis. The distinction between research chemical labeling and human use is significant because quality standards and oversight differ.
Anti-doping laboratories identify GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the usual matrix, and detection can occur after the parent compound has cleared from blood. The exact detection window depends on dose, formulation, individual metabolism, and assay sensitivity. Because the compound is prohibited at all times, athletes are subject to testing in and out of competition. Analytical methods continue to improve as new metabolites and designer analogs are characterized.
GW501516 acts as a ligand for PPAR delta, a nuclear receptor that regulates transcription of genes involved in fatty acid oxidation and energy use. Activation of this receptor in skeletal muscle shifts metabolism toward fat burning in animal models. The compound does not burn fat directly; it changes gene expression over hours to days. Researchers study it to understand metabolic flexibility and exercise adaptation. Effects observed in rodents are not automatically expected in humans.
Preclinical research reported that GW501516 increased running endurance in mice and improved lipid profiles in some animal species. Early human trials explored effects on high-density lipoprotein cholesterol, triglycerides, and glucose handling, but the program was discontinued. Published human data are sparse and do not establish efficacy for any condition. Studies also examined PPAR delta in cancer biology, with conflicting findings across models. The relationship between receptor activation, tissue context, and disease risk remains an active area of investigation.
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.
== Research == Under research are GLP1 poly-agonist peptides, dual and triple receptor agonists such as tirzepatide (GLP-1 + GIP) and retatrutide (GLP-1 + GIP + glucagon), and combinations such as cagrilintide/semaglutide, which combines semaglutide with a dual amylin and calcitonin receptor agonist, and amycretin, which acts as both a GLP1 and an amylin agonist.
Research has focused on changing the mixture of keratins produced in the skin. There are 54 known keratin genes—of which 28 belong to the type I intermediate filament genes and 26 to type II—which work as heterodimers. Many of these genes share substantial structural and functional similarity, but they are specialized to cell type and/or conditions under which they are normally produced. If the balance of production could be shifted away from the mutated, dysfunctional keratin gene toward an intact keratin gene, symptoms could be reduced. For example, sulforaphane, a compound found in broccoli sprouts and few other vegetables, was found to reduce blistering in a mouse model to the point where affected pups could not be identified visually, when injected into pregnant mice (5 μmol/day = 0.9 mg) and applied topically to newborns (1 μmol/day = 0.2 mg in jojoba oil). As of 2008, clinical research at the University of Minnesota has explored allogeneic bone marrow transplantation for RD and junctional EB, treating a two-year-old child who is one of two brothers with EB. A second transplant has also been performed on the child's older brother. A Missouri boy has also successfully undergone the transplant, as well as a 5 year old boy from Alabama. So far there have been 12 successful transplants. Another transplant is scheduled for a California baby. A clinical trial is planned for 30 subjects. However, the immune suppression that bone marrow transplantation requires causes a risk of serious infections with large scale blisters and skin erosion.
=== Sleep === Gabapentin is effective in treating sleep disorders such as insomnia and restless legs syndrome that are the result of an underlying illness, but comes with some risk of discontinuation and withdrawal symptoms after prolonged use at higher doses. Gabapentin enhances slow-wave sleep in people with primary insomnia. It also improves sleep quality by elevating sleep efficiency and decreasing spontaneous arousal.
Sources: en.wikipedia.org
=== Beginnings === Chromosomes were first observed in plant cells by Carl Nägeli in 1842. Their behavior in animal (salamander) cells was described by Walther Flemming, the discoverer of mitosis, in 1882. The name was coined by another German anatomist, von Waldeyer in 1888. The next stage took place after the development of genetics in the early 20th century, when it was appreciated that the set of chromosomes (the karyotype) was the carrier of the genes. Levitsky seems to have been the first to define the karyotype as the phenotypic appearance of the somatic chromosomes, in contrast to their genic contents. Investigation into the human karyotype took many years to settle the most basic question: how many chromosomes does a normal diploid human cell contain? In 1912, Hans von Winiwarter reported 47 chromosomes in spermatogonia and 48 in oogonia, concluding an XX/XO sex determination mechanism. Painter in 1922 was not certain whether the diploid number of humans was 46 or 48, at first favoring 46. He revised his opinion later from 46 to 48, and he correctly insisted on humans having an XX/XY system of sex-determination. Considering their techniques, these results were quite remarkable. In science books, the number of human chromosomes remained at 48 for over thirty years. New techniques were needed to correct this error. Joe Hin Tjio working in Albert Levan's lab was responsible for finding the approach:
== Evolution == Similar to any other protein, enzymes change over time through mutations and sequence divergence. Given their central role in metabolism, enzyme evolution plays a critical role in adaptation. A key question is therefore whether and how enzymes can change their enzymatic activities alongside. It is generally accepted that many new enzyme activities have evolved through gene duplication and mutation of the duplicate copies although evolution can also happen without duplication. One example of an enzyme that has changed its activity is the ancestor of methionyl aminopeptidase (MAP) and creatine amidinohydrolase (creatinase) which are clearly homologous but catalyze very different reactions (MAP removes the amino-terminal methionine in new proteins while creatinase hydrolyses creatine to sarcosine and urea). In addition, MAP is metal-ion dependent while creatinase is not, hence this property was also lost over time. Small changes of enzymatic activity are extremely common among enzymes. In particular, substrate binding specificity (see above) can easily and quickly change with single amino acid changes in their substrate binding pockets. This is frequently seen in the main enzyme classes such as kinases. Artificial (in vitro) evolution is now commonly used to modify enzyme activity or specificity for industrial applications (see below).
The study showed that MMP-3 accomplishes this damage by degrading claudin-5, occludin, and ZO-1 (another tight junction protein), similar to how MMP-3 damages the BBB. The increase in blood-brain barrier and blood-spinal cord barrier permeability allows for more neutrophils to infiltrate the brain and spinal cord at the site of inflammation. Neutrophils carry MMP-9., which has also been shown to degrade occludin. This leads to further disruption of the BBB and BSCB
Through strengthening adhesion, α2β1 integrin facilitates aggregation of extra platelets and the development of a stable thrombus that is capable of stopping the bleeding. The engagement of collagen receptors through α2β1 integrin stimulates inside-out signaling and platelet spreading as well as remodeling of the cytoskeleton. This results in increased surface area of platelets, making their contact with surrounding platelets and coagulation factors possible. Platelet adhesion being important for physiological hemostasis, any variations in the expression of ITGA2 gene or its products may affect the rate of bleeding or development of thrombosis. There are some polymorphism of the ITGA2 gene, the presence of which results in various collagen-binding capacities in people due to different densities of the α2β1 receptor on the platelets' surface. Though the impact of these variations is still unclear, their relation to myocardial infarction and Ischemic stroke has been studied. Therefore, α2β1 receptor still remains an interesting Therapeutic target for the prevention of pathological thrombosis.
Sources: en.wikipedia.org
When the cells' roles are close to complete, unneeded cells undergo apoptosis. Maturation (remodeling): During maturation and remodeling, collagen is realigned along tension lines, and cells that are no longer needed are removed by programmed cell death, or apoptosis.
PmF3 + 3 Li → Pm + 3 LiF The promethium sample produced was used to measure a few of the metal's properties, such as its melting point. In 1963, ion-exchange methods were used at ORNL to prepare about ten grams of promethium from nuclear reactor fuel processing wastes. Promethium can be either recovered from the byproducts of uranium fission or produced by bombarding 146Nd with neutrons, turning it into 147Nd, which decays into 147Pm through beta decay with a half-life of 11 days.
Phenformin is an antidiabetic drug from the biguanide class. It was marketed as DBI by Ciba-Geigy, but was withdrawn from most markets in the late 1970s due to a high risk of lactic acidosis, which was fatal in 50% of cases. Phenformin was developed in 1957 by Ungar, Freedman and Seymour Shapiro, working for the U.S. Vitamin Corporation. Clinical trials begun in 1958 showed it to be effective, but with gastrointestinal side effects.
== Protein Intake and Muscle Hypertrophy == Research on resistance training shows that increasing daily protein intake supports gains in muscle mass, but the benefit have diminishing returns. A large meta-analysis by Morton et al. (2018) found that muscle growth increases as protein intake rises up to about 1.6 g/kg/day, after which additional protein offers little added effect. A similar dose response analysis by Tagawa et al. (2020) reported that while higher protein intakes are generally associated with greater lean mass gains, the effect plateaus once basic requirements for resistance trained individuals are met. Together, these findings suggest that moderate but adequate protein intake is sufficient for maximizing hypertrophy in most healthy adults.
== Politics and administration == Le Havre is one of two sub-prefectures of Seine-Maritime and the second largest subprefecture in France after Reims. It is the capital of the Arrondissement of Le Havre which includes 168 communes. It is also the largest member of the Le Havre Seine Métropole.
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.
No. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.