Reference standard 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 2026-04-03. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
| Property | Value | Notes |
|---|---|---|
| CAS Registry Number | 317318-70-0 | Unique identifier for the compound. |
| Chemical class | PPARδ agonist | Synthetic ligand for peroxisome proliferator-activated receptor delta. |
| Appearance | White to off-white solid | Typical form of research-grade material. |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water. |
| Typical storage | -20°C | Recommended for long-term storage of stock solutions. |
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.
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
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.
Pressure sores, also called bedsores or pressure ulcers, are injuries to the skin and tissue caused by staying in one position for too long. To treat them, the skin should be washed with lukewarm water and dried completely, especially in areas where skin touches skin, like between the toes, under the breasts, in the groin, and under the arms. Harsh soaps should be avoided—it is better to use gentle, pH-balanced cleansers. Moisturizers can help protect the skin, but they shouldn't be used between the toes. It is best to apply a hypoallergenic moisturizer twice a day, especially on the arms and legs, and avoid rubbing the skin too hard.
=== St. Louis Bar & Grill === Founded in Toronto in 1992, St. Louis Bar & Grill is a Canadian restaurant chain known for their chicken wings and casual dining. The company has expanded to more than 80 locations across Canada and is known for its signature wings, garlic dill sauce, and sports-bar atmosphere. In 2022, the chain was acquired by Aegis Brands.
=== Table I === acetic anhydride N-Acetylanthranilic acid ephedrine ergometrine ergotamine isosafrole lysergic acid 3,4-methylenedioxyphenyl-2-propanone norephedrine phenylacetic acid 1-phenyl-2-propanone alpha-phenylacetoacetonitrile (APAAN) piperonal potassium permanganate pseudoephedrine safrole The salts of the substances listed in this Table whenever the existence of such salts is possible.
=== Blood-feeding insects === Many blood-feeding insects like horseflies or mosquitoes inject multiple bioactive compounds into their prey. These insects have been used by practitioners of Eastern Medicine for hundreds of years to prevent blood clot formation or thrombosis. However, modern medical research has only recently begun to investigate the drug development potential of blood-feeding insect saliva. These compounds in the saliva of blood feeding insects are capable of increasing the ease of blood feeding by preventing coagulation of platelets around the wound and provide protection against the host's immune response. Currently, over 1280 different protein families have been associated with the saliva of blood feeding organisms.
Sources: en.wikipedia.org
The introduction of the F gene of SeV in the form of a plasmid into the tumor tissue in mice by electroporation showed that the expression of the F gene increases the T cell infiltration of the tumor with CD4+ and CD8+ cells and inhibits tumor growth. It was also shown in other similar experiments that cancer cells themselves, transfected with plasmids that encode viral membrane glycoproteins with fusion function, cause the collective death of neighboring cells forming syncytium with them. Recruitment of bystander cells into the syncytium leads to significant regression of the tumor.
== Mathematical models == There are several mathematical models that describe collective cell motion. Typically, a Newtonian equation of motion for a system of cells is solved. Several forces act on each individual cell, examples are friction (between environment and other cells), chemotaxis and self-propulsion. The latter implies that cells are active matter far from thermal equilibrium that are able to generate force due to myosin-actin contractile motion. An overview over physical description of collective cell migration explains that the following types of models can be used:
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.
Integral membrane proteins are permanently attached to the membrane. Such proteins can be separated from the biological membranes only using detergents, nonpolar solvents, or sometimes denaturing agents. They can be classified according to their relationship with the bilayer:
Liquids can form solutions with gases, solids, and other liquids. Two liquids are said to be miscible if they can form a solution in any proportion; otherwise they are immiscible. As an example, water and ethanol (drinking alcohol) are miscible whereas water and gasoline are immiscible. In some cases a mixture of otherwise immiscible liquids can be stabilized to form an emulsion, where one liquid is dispersed throughout the other as microscopic droplets. Usually this requires the presence of a surfactant in order to stabilize the droplets. A familiar example of an emulsion is mayonnaise, which consists of a mixture of water and oil that is stabilized by lecithin, a substance found in egg yolks.
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist developed for research. It has not been approved as a medication in any country. It is classified as an unapproved drug and a prohibited substance in sport.
No. Cardarine is not an anabolic steroid; it belongs to a different chemical class that targets PPARδ. Steroids act primarily through androgen receptors, while cardarine acts through a nuclear receptor involved in metabolism.
Some rodent studies reported increased endurance and changes in fat metabolism after cardarine exposure. Long-term studies in animals also raised concerns about cancer in certain tissues. Human trial data are limited, so these findings cannot be directly translated to people.
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.