If you have been reading about GW501516 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.
Updated 2025-11-13. Numbers and descriptions here follow the published literature rather than marketing material.
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 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.
GW501516 binds and activates PPARδ, a nuclear receptor that influences transcription of genes involved in fatty acid oxidation and energy use. Activation shifts some metabolic pathways in preclinical models, which is why the compound has been studied for lipid disorders and exercise-related endpoints. The exact downstream effects in humans are incompletely mapped. PPARδ is expressed in many tissues, including skeletal muscle, liver, and adipose tissue, so broad activation may have varied consequences. Researchers continue to examine how selective or partial activation might alter the balance between benefits and risks.
Published human data are sparse and mostly come from early-phase trials. Those studies examined short-term changes in lipids, glucose, and exercise capacity, but they were not large enough to establish efficacy or long-term safety. Some animal experiments reported increased running endurance, yet such findings do not prove a performance benefit in people. Anti-doping laboratories detect GW501516 and its metabolites in urine or blood using liquid chromatography-tandem mass spectrometry. Detection windows depend on dose, sample type, and individual metabolism. The method is sensitive enough to identify trace residues in tested samples.
| 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. |
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.
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.
Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.
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.
In the fitness and bodybuilding literature, cardarine is frequently discussed as an endurance agent or fat-loss compound, although such claims are not supported by robust clinical evidence. Online descriptions often mix animal data, user anecdotes, and marketing language. Researchers who study PPARδ agonists distinguish between receptor activation in controlled experiments and unsupervised use of unverified products. The latter introduces unknown purity, dose, and interactions, making reported experiences difficult to interpret scientifically.
GW501516 acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in transcription of genes related to lipid handling and energy use. Activation of PPARδ can shift skeletal muscle toward greater fatty acid oxidation in animal models, which is one reason it drew interest for metabolic disease and exercise research. The exact downstream effects depend on tissue, species, dose, and duration. Human data are sparse, so many proposed benefits remain hypotheses rather than established clinical outcomes.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
Cardarine is a common name for GW501516, a synthetic compound developed in the 1990s through research collaborations involving GlaxoSmithKline. It belongs to a class of molecules known as peroxisome proliferator-activated receptor delta agonists. Early studies explored its effects on lipid metabolism and energy expenditure in animal models. The compound was never approved as a human medicine, and clinical development was discontinued. In the years since, it has appeared in fitness and bodybuilding communities as a performance-enhancing substance. Regulatory agencies classify it as an unapproved drug.
PPARδ is a nuclear receptor that regulates gene expression related to fatty acid oxidation, glucose homeostasis, and mitochondrial function. GW501516 binds to this receptor with high affinity and activates downstream signaling in skeletal muscle and other tissues. Animal studies reported increased endurance and altered fuel preference, but human data remain limited and inconsistent. The precise relationship between receptor activation and observed physiological changes is still an area of active investigation. Researchers have also examined whether the compound affects inflammation or cell proliferation. No approved therapeutic indication exists for cardarine.
Humulin R (REGULAR human insulin injection [rDNA origin]) is a short-acting insulin that has a relatively short duration of activity as compared with other insulins. Humulin R Regular U-500 (Concentrated) insulin human injection, USP (rDNA Origin) is a stronger concentration (500 units/mL) of Humulin R. Humulin 70/30 (70% human insulin isophane suspension, 30% human insulin injection [rDNA origin]) is a mixture insulin. It is an intermediate-acting insulin combined with the onset of action of Humulin Humulin 50/50 (50% human insulin isophane suspension, 50% human insulin injection [rDNA origin]) is a mixture insulin. It is an intermediate-acting insulin combined with the onset of action of Humulin R. In UK these include:
N-methyl putrescine then undergoes deamination into 4-methylaminobutanal by the N-methyl putrescine oxidase (MPO) enzyme, 4-methylaminobutanal then spontaneously cyclize into N-methyl-Δ1-pyrrollidium cation. The final step in the synthesis of nicotine is the coupling between N-methyl-Δ1-pyrrollidium cation and nicotinic acid. Although studies conclude some form of coupling between the two component structures, the definite process and mechanism remains undetermined. The current agreed theory involves the conversion of nicotinic acid into 2,5-dihydropyridine through 3,6-dihydronicotinic acid. The 2,5-dihydropyridine intermediate would then react with N-methyl-Δ1-pyrrollidium cation to form enantiomerically pure (−)-nicotine.
=== Assisted reproduction === PRP can be inoculated into the uterine cavity, to improve endometrial receptivity in cases of refractory endometrium. Studies have reported that intrauterine inoculation of PRP before embryo transfer can thicken the endometrium and improve reproductive prognosis. PRP has been studied for the management of Asherman's Syndrome. PRP can be inoculated experimentally into the ovary to promote ovarian tissue regeneration. The main applications would be in cases of diminished ovarian reserve or premature ovarian failure. A 2023 retrospective observational study reported PRP's effectiveness in rejuvenating ovarian fertility and viability in terms of "the influence of intraovarian injection of autologous PRP on the levels of E2". and pregnancy outcome in women treated with PRP who had a history of infertility, hormonal abnormalities, an absence of menstrual cycle, and premature ovarian failure in a single centre." A 2024 review showed that PRP is beneficial when used as intraovarian injections for women with decreased fertility. PRP used for fertility trouble increases AFC, number of cleavage embryos, and improves cancellation rate in women with poor ovarian reserve. However, "Although there was an improvement of baseline hormones (anti-Müllerian hormone, follicle-stimulating hormone, and estradiol) after intraovarian injection of PRP, this improvement failed to reach statistical significance (except the improvement of serum AMH analyzed in quasi-experimental studies)."
Sources: en.wikipedia.org
Chitosan is produced commercially by deacetylation of chitin, which is the structural element in the exoskeleton of crustaceans (such as crabs and shrimp) and cell walls of fungi. A common method for obtaining chitosan is the deacetylation of chitin using sodium hydroxide in excess as a reagent and water as a solvent. The reaction follows first-order kinetics though it occurs in two steps; the activation energy barrier for the first stage is estimated at 48.8 kJ·mol−1 at 25–120 °C (77–248 °F) and is higher than the barrier to the second stage.
Syeda, F; Fagan, RL; Wean, M; Avvakumov, GV; Walker, JR; Xue, S; Dhe-Paganon, S; Brenner, C (2011). "The Replication Focus Targeting Sequence (RFTS) Domain is a DNA-Competitive Inhibitor of Dnmt1". J. Biol. Chem. 286 (17): 15344–15351. doi:10.1074/jbc.M110.209882. PMC 3083197. PMID 21389349. Bogan, KL; Brenner, C (1 August 2008). "Nicotinic Acid, Nicotinamide, and Nicotinamide Riboside: A Molecular Evaluation of NAD + Precursor Vitamins in Human Nutrition". Annual Review of Nutrition. 28 (1): 115–130. doi:10.1146/annurev.nutr.28.061807.155443. ISSN 0199-9885. PMID 18429699. Tempel, W; Rabeh, WM; Bogan, KL; Belenky, P; Wojcik, M; Seidle, HF; Nedyalkova, L; Yang, T; Sauve, AA; Park, HW; Brenner, C (2007-10-02). "Nicotinamide riboside kinase structures reveal new pathways to NAD+". PLOS Biology. 5 (10) e263. doi:10.1371/journal.pbio.0050263. ISSN 1545-7885. PMC 1994991. PMID 17914902. Robu, ME; Larson, JD; Nasevicius, A; Beiraghi, S; Brenner, C; Farber, SA; Ekker, SC (25 May 2007). "p53 Activation by Knockdown Technologies". PLOS Genetics. 3 (5) e78. doi:10.1371/journal.pgen.0030078. ISSN 1553-7404. PMC 1877875. PMID 17530925. S2CID 9914091. Belenky, P; Bogan, KL; Brenner, C (January 2007). "NAD+ metabolism in health and disease". Trends in Biochemical Sciences. 32 (1): 12–19. doi:10.1016/j.tibs.2006.11.006. PMID 17161604. Belenky, P; Racette, FG; Bogan, KL; McClure, JM; Smith, JS; Brenner, C (4 May 2007). "Nicotinamide riboside promotes Sir2 silencing and extends lifespan via Nrk and Urh1/Pnp1/Meu1 pathways to NAD+". Cell. 129 (3): 473–84. doi:10.1016/j.cell.2007.03.024.
Although Bugie was considered to be the second author on the Proceedings of the Society for Experimental Biology paper, she was not listed on the patent submission. Bugie's contributions to Waksman's lab were great. In addition to her work on streptomycin, she also helped develop other antimicrobial substances, had two peer-reviewed publications, and researched the use of antimicrobials against plant pathogens, among several other important contributions to the scientific field, particularly in regard to microbiology.
=== Mutational convergence === The most well-studied example is the Spike protein of SARS-CoV-2, which independently evolved at the same positions regardless of the underlying sublineage. The most eminent examples from the pre-Omicron era were E484K and N501Y, while in the Omicron era examples include R493Q, R346X, N444X, L452X, N460X, F486X, and F490X.
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.
Anti-doping and clinical laboratories commonly use liquid chromatography-tandem mass spectrometry. The method can identify GW501516 and its metabolites in urine or blood. Detection depends on sample timing and the amount present.