Everything below concerns PPARδ. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-01-23. Numbers and descriptions here follow the published literature rather than marketing material.
Cardarine is not approved for human therapeutic use in any major jurisdiction. It appears on the World Anti-Doping Agency Prohibited List as a PPARδ agonist within the hormone and metabolic modulators category. Sports organizations test for it because it has been detected in athlete samples and seized products. Regulatory actions against marketed research chemical versions have occurred in several countries, though enforcement varies. Availability through unregulated channels complicates oversight.
Analytical laboratories typically identify cardarine and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is a common matrix in anti-doping testing, while blood and tissue may be used in research settings. Detection windows depend on the assay, the sample matrix, and the compound's metabolism. Because cardarine is extensively metabolized, laboratories often target specific metabolites to improve sensitivity and confirmation. Reference standards are required for reliable quantification. Method validation includes checks for selectivity, linearity, and carryover.
A persistent misconception is that cardarine is a fat-burning drug or a safe alternative to anabolic steroids. No approved therapeutic product exists, and human safety data are limited. The tumor findings in rodents remain a central concern in scientific reviews. Products sold online may contain inaccurate labels, impurities, or different compounds entirely, which complicates any assessment of effects. Independent testing of such products has reported frequent mislabeling. For these reasons, discussions in the literature emphasize risks and unknowns rather than benefits.
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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved for human therapeutic use | No marketing authorization identified in major jurisdictions. |
| Anti-doping class | PPARδ agonist; hormone and metabolic modulators | Listed on the WADA Prohibited List. |
| Common test matrix | Urine | Also blood and tissue in research settings. |
| Typical analytical method | LC-MS/MS | Targets parent compound and metabolites. |
| Major safety signal | Tumor findings in rodents | Human relevance not established; limited human data. |
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.
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.
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.
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.
Cardarine can be detected in biological samples and product materials using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The method separates compounds by chromatography and identifies them by mass-to-charge transitions, allowing low-level detection in urine or blood. Sample preparation often involves enzymatic hydrolysis, solid-phase extraction, or protein precipitation. Certified reference materials and isotope-labeled internal standards improve quantification. Detection windows depend on metabolism, matrix, and assay sensitivity, so no single universal window applies.
=== Abuse of migrants === According to Human Rights Watch, Houthi militias have "beaten, raped, and tortured detained migrants and asylum seekers from the Horn of Africa." UN experts have warned that female migrants face sexual violence, forced labor, and forced drug trafficking by smugglers who collaborate with the Houthi-controlled Yemen Immigration, Passport and Nationality Authority (IPNA).
== Science, technology and mathematics == Central limit theorem, in probability and statistics Construal level theory, a statistical social theory Central location test, a marketing research technique Cross-laminated timber, an engineered wood
== External links == Emil Fischer on Nobelprize.org including his Nobel Lecture Nobel Lecture, 12 December 1902 Syntheses in the Purine and Sugar Group Eminent Chemists of Our Time By Benjamin Harrow pages 216–239, published 1920 by Von Nostrand Company at books.google.com. Aders Plimmer, R. H. (July 1907). "The work of Emil Fischer and his school on the chemistry of the proteins". Science Progress in the Twentieth Century. 2 (5): 88–120. Guide to the Emil Fischer Papers at The Bancroft Library Text-book of Physiological Chemistry in Thirty Lectures by Emil Abderhalden, translated by William Thomas Hall and George Defren; published 1908 by Wiley Company, has many technical references to Fischer's work in Chemistry. American Journal of Diseases of Children 1911 volume 2 by the American Medical Association also refers to Fischer's work. An Introduction to the History of Medicine: With Medical Chronology by Fielding Hudson Garrison, page 708 refers to Fischer and Merings discovery of the drugs veronal(1904) and proponal(1905), published 1921 by Saunders Company. 1914 Year Book of the American Pharmaceutical Association, page 438 abstracts Fischer and Strauss's work on Phenol-Glucosides – Synthetic Production from Berlin d.D Chem. Germany, page 45(1912) No. 12. Texts on Wikisource: "Fischer, Emil". New International Encyclopedia. 1905. "Fischer, Emil". Encyclopædia Britannica (11th ed.). 1911. "Fischer, Emil". Encyclopedia Americana. 1920.
Sources: en.wikipedia.org
=== Optic nerve blood supply === The optic nerve head, or prelaminar disc, primarily receives blood from the peripapillary choroidal arterioles, which stem from the elliptical anastomotic annulus connected to the circle of Zinn-Haller. The circle of Zinn-Haller is formed by branches of the lateral and posterior ciliary arteries. Beyond this region, different segments of the optic nerve are supplied by various networks of arteries and capillaries originating from the ophthalmic artery and the central retinal artery. The Zinn-Haller circle also provides blood to the thin, sieve-like section of the eye's outer layer and the optic nerve fibers within it through small, inward-facing arteries. The area just behind this layer in the optic nerve is vascularized by small returning arteries and minute blood vessels that arise from the eye's surrounding circulation and the main ophthalmic artery, interweaving through the nerve's supporting fibers. The parts of the optic nerve located within the eye socket and the canal it traverses receive blood from small arteries branching off the primary network surrounding the eye, as well as from the central retinal artery. Fluorescein angiographic studies have demonstrated that during the acute phase of NAION, there is a delay in blood flow to the optic disc, suggesting a potential impairment in the arteries directly supplying it. Other research indicates that a drop in blood pressure within specific critical areas of the optic disc's blood supply network may increase its susceptibility to damage.
== Structure == Disulfur difluoride has a chain structure F−S−S−F. The angle between the Fa−S−S and S−S−Fb planes is 87.9°, while the angles of Fa−S−S and S−S−Fb are equivalent, and are equal to 108.3°. Both S−F bonds are equivalent and their length is 163.5 pm, while the length of the S−S bond is 189 pm. This structure is referred to as gauche, and is similar to H2O2. There is a branched isomer of disulfur difluoride, thiothionyl fluoride, with the structure S=SF2.
=== Hairpins === A hairpin is a special case of a turn, in which the direction of the protein backbone reverses and the flanking secondary structure elements interact. For example, a beta hairpin connects two hydrogen-bonded, antiparallel β-strands (a rather confusing name, since a β-hairpin may contain many types of turns – α, β, γ, etc.). Beta hairpins may be classified according to the number of residues that make up the turn - that is, that are not part of the flanking β-strands. If this number is X or Y (according to two different definitions of β sheets) the β hairpin is defined as X:Y. Beta turns at the loop ends of beta hairpins have a different distribution of types from the others; type I′ is commonest, followed by types II′, I and II.
=== Column technology === Early gas chromatography used packed columns, made of block 1–5 m long, 1–5 mm diameter, and filled with particles. The resolution of packed columns was improved by the invention of capillary column, in which the stationary phase is coated on the inner wall of the capillary.
Sources: en.wikipedia.org
Necrophages and their microbiotas ("friendly bacteria") produce several molecules of medical interest. These include molecules that can bind to bacterial pathogens (e.g. lectins), inhibit pathogen growth (e.g. chitin, cyclic lipopeptides), and kill pathogens (e.g. antimicrobial peptides, lysozymes). In nature, these molecules are thought to block pathogen entry into the integuments (e.g. skin, cuticle) and circulatory systems (e.g. blood, hemolymph) of necrophages, and enable the immune systems of necrophages to detect, inhibit and kill any pathogens that breach these barriers. Research is underway in Germany, China, the USA and other countries to develop these molecules for use in medicine. Possible applications include antimicrobial wound dressings, antibacterial drugs, and drug delivery systems for bacterial infections.
=== Coronary artery disease === Homocysteine, a sulfur based amino acid is the main product of methionine demethylation. Elevated homocysteine is an independent risk factor for cardiovascular disease and inversely correlated to consumed vitamin B12/B6 and folate levels. Homocysteine methylation to methionine is catalyzed by MTR, resulting in appropriate intracellular levels of methionine and tetrahydrofolate, alongside non-toxic homocysteine levels. The GG phenotype promotes the development of premature coronary artery disease (CAD) independent of hyperhomocysteinemia. Hyperhomocysteinemia is associated with cerebral, coronary and peripheral atherosclerotic pathology as it promotes endothelial cell dysfunction, platelet adhesion and vascular smooth muscle cell proliferation. DNA damage and homocysteine levels are proportional to CAD severity. Micronucleus frequency in human lymphocytes, dependent on homocysteine levels increases reactive oxygen species and uracil incorporation in DNA methylation, promoting genetic alterations and point mutations. The (MTRR):c.66A>G, polymorphism containing chromosome is prone to fragmentation. This chromosomal loss or global DNA hypomethylation results in under condensation of pericentromeric heterochromatin, micronucleus formation and elevated risks of aneuploidy. Co-expression of this mutation and the 677T polymorphism in methionine tetrahydrofolate reductase (MTHFR) Methylenetetrahydrofolate reductase act to further the extent of DNA damage.
At the end of the electrophoretic separation, all proteins are sorted by size and can then be analyzed by other methods, e. g. protein staining such as Coomassie staining (most common and easy to use), silver staining (highest sensitivity), stains all staining, Amido black 10B staining, Fast green FCF staining, fluorescent stains such as epicocconone stain and SYPRO orange stain, and immunological detection such as the Western Blot. The fluorescent dyes have a comparatively higher linearity between protein quantity and color intensity of about three orders of magnitude above the detection limit (the quantity of protein that can be estimated by color intensity). When using the fluorescent protein dye trichloroethanol, a subsequent protein staining is omitted if it was added to the gel solution and the gel was irradiated with UV light after electrophoresis. In Coomassie staining, gel is fixed in a 50% ethanol 10% glacial acetic acid solution for 1 hr. Then the solution is changed for fresh one and after 1 to 12 hrs gel is changed to a staining solution (50% methanol, 10% glacial acetic acid, 0.1% coomassie brilliant blue) followed by destaining changing several times a destaining solution of 40% methanol, 10% glacial acetic acid.
Sources: en.wikipedia.org
No. Cardarine has not received approval for human therapeutic use in major jurisdictions. It remains an investigational compound.
It is classified as a PPARδ agonist on the WADA Prohibited List. Anti-doping laboratories can detect it and its metabolites in urine. Its use is banned in competition and usually out of competition.
Rodent studies reported increased tumor incidence at multiple sites. The human relevance remains uncertain, but the findings contributed to discontinuation of development. No long-term human cancer data are available.
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.