unapproved substance 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 2025-12-11. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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 |
|---|---|---|
| IUPAC name | {4-[({4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl}methyl)sulfanyl]phenoxy}acetic acid | Systematic name for GW501516 |
| CAS Registry Number | 317318-70-0 | Unique identifier for the parent compound |
| Molecular formula | C21H18F3NO3S2 | Includes carbon, hydrogen, fluorine, nitrogen, oxygen, and sulfur |
| Molecular weight | 453.5 g/mol | Approximate value for the neutral form |
| Appearance | White to off-white powder | Typical description for purified laboratory material |
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.
The pharmacological interest in cardarine centers on PPARδ activation and its downstream effects on lipid handling and mitochondrial function. In animal studies, PPARδ agonists have been associated with changes in exercise endurance and fatty acid utilization, though results vary by model and protocol. Human data remain sparse, and the absence of large controlled trials limits conclusions about efficacy. Researchers often describe the compound as a tool for probing PPARδ biology rather than a proven therapeutic agent.
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
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.
Most animals rely on biomass and bioenergy produced by plants and phytoplanktons (collectively called producers) through photosynthesis. Herbivores, as primary consumers, eat the plant material directly to digest and absorb the nutrients, while carnivores and other animals on higher trophic levels indirectly acquire the nutrients by eating the herbivores or other animals that have eaten the herbivores. Animals oxidise carbohydrates, lipids, proteins and other biomolecules in cellular respiration, which allows the animal to grow and to sustain basal metabolism and fuel other biological processes such as locomotion. Of the 550 gigatons of carbon biomass on Earth, animals account for 2 gigatons. Some benthic animals living close to hydrothermal vents and cold seeps on the dark sea floor consume organic matter produced through chemosynthesis (via oxidising inorganic compounds such as hydrogen sulfide) by archaea and bacteria. Animals originated in the ocean; all extant animal phyla, except for Micrognathozoa and Onychophora, feature at least some marine species. However, several lineages of arthropods begun to colonise land around the same time as land plants, between 510 and 471 million years ago, during the Late Cambrian or Early Ordovician periods. Vertebrates such as the lobe-finned fish Tiktaalik started to move on to land in the late Devonian, about 375 million years ago.
== Other biology == Yeast grown under high concentrations of selenomethionine is able to convert selenomethionine into selenocysteine, much like methionine can be converted into cystine. Existence of selenocysteine is enough to trick the cystine-tRNA ligase into producing a tRNACys linked to selenocystine, resulting in the production of non-functional proteins and cytotoxicity.
=== Economics === Trastuzumab costs about US$70,000 for a full course of treatment. Australia has negotiated a lower price of A$50,000 per course of treatment. Since October 2006, trastuzumab has been made available for Australian women and men with early-stage breast cancer via the Pharmaceutical Benefits Scheme. This is estimated to cost the country over A$470 million for 4–5 years supply of the drug. Roche has agreed with Emcure in India to make an affordable version of this cancer drug available to the Indian market. Roche has changed the brand name of the drug and has re-introduced an affordable version of the same in the Indian market. The new drug named Herclon would cost approximately RS75,000 INR (US$ 870) in the Indian market. On 16 September 2014, Genentech notified hospitals in the United States that, as of October, trastuzumab could only be purchased through their selected specialty drugs distributors not through the usual general line wholesalers. By being forced to purchase through specialty pharmacies, hospitals lost rebates from the big wholesalers and the ability to negotiate cost-minus discounts with their wholesalers.
Triosephosphate isomerase rapidly interconverts dihydroxyacetone phosphate with glyceraldehyde 3-phosphate (GADP) that proceeds further into glycolysis. This is advantageous, as it directs dihydroxyacetone phosphate down the same pathway as glyceraldehyde 3-phosphate, simplifying regulation.
Sources: en.wikipedia.org
The polypeptide hormone IGF1 is synthesized primarily in the liver upon stimulation by growth hormone (GH). It is a key mediator of anabolic activities in numerous tissues and cells, such as growth hormone-stimulated growth, metabolism and protein translation. Due to its participation in the GH-IGF1 axis it contributes among other things to the maintenance of muscle strength, muscle mass, development of the skeleton and is a key factor in brain, eye and lung development during fetal development. Studies have shown the importance of the GH/IGF1 axis in directing development and growth, where mice with an IGF1 deficiency had a reduced body- and tissue mass. Mice with an excessive expression of IGF1 had an increased mass.
Due to the immune response, LTLs can experience the accelerated blood clearance (ABC) phenomenon. This phenomenon is more common in repeated dosage usage of LTLs, such as multi-dose PEGylated formulas, because of immunological memory. The pharmokinetics and clearance rates of the second dose have been shown to be significantly reduced while accumulation in the spleen and liver increases. This poses challenges for clinical applications of LTLs that require multiple doses to be effective. Ligand-targeted liposomes need specific conditions to remain intact for use. Controlling environmental factors such as temperature and pH is necessary to maintain the integrity of the molecules. This can be helpful for temperature-sensitive or pH-dependent drug release conditions but is harmful if the pH changes at an inopportune time. This technology can also be used in combination with enzymes such as in Gal-Dox, which releases active doxorubicin in combination with β-Galactosidase. Making sure the compound does not encounter the enzyme too early is also important for effective usage. There is a possibility that LTLs lead to immunosuppression. LTLs are cleared through the RES which is part of the innate immune system. Macrophage saturation to remove the liposomes could impact the ability of the phagocytic cells to function properly to conduct immune functions. Significant immune suppression has not been observed in clinical cases for therapeutic doses of LTLs containing non-cytotoxic drugs.
The rRNA molecules are thought responsible for its enzymatic activity, as no amino-acid residues lie within 18Å of the enzyme's active site, and, when the majority of the amino-acid residues in the ribosome were stringently removed, the resulting ribosome retained its full peptidyl transferase activity, fully able to catalyze the formation of peptide bonds between amino acids. A pseudo 2 fold symmetry of the region surrounding the peptidyl transferase center (PTC) led to the hypothesis of the Proto-Ribosome, that a vestige of an ancient dimeric molecule from the RNA world is functioning within the ribosome. An RNA molecule derived from the 23S ribosomal RNA sequence for this region has been synthesized in the lab in 2022 to test the proto-ribosome hypothesis. It was able to dimerize and to form peptide bonds. A much shorter RNA molecule has been synthesized in the laboratory in 1999 with the ability to form peptide bonds, and it has been suggested that rRNA has evolved from a similar molecule. tRNA is suggested to have also evolved from RNA molecules that began to catalyze amino acid transfer (also see the discussion of amino acid-RNA ligation above). The current core of the ribosome, the PTC, may also have evolved from the concatenation of five proto-tRNAs. A RNP world-type hypothesis is that the tRNA acceptor stem and the catalytic domain of the aaRS came earlier than the genetic code and the PTC.
While starting doses may be adjusted based on the amount of opioids reportedly used, most clinical guidelines suggest doses start low (e.g., at doses not exceeding 40 mg daily) and be titrated gradually. It has been found that doses of 40 mg per day were sufficient to help control the withdrawal symptoms but not enough to curb the cravings for the drug. Doses of 80 to 100 mg per day have shown higher rates of success in patients and less illicit heroin use during the maintenance therapy. However, higher doses do put a patient more at risk for overdose than a moderately low dose (e.g. 20 mg/day). Methadone maintenance has been shown to reduce the transmission of bloodborne viruses associated with opioid injection, such as hepatitis B and C, and/or HIV. The principal goals of methadone maintenance are to relieve opioid cravings, suppress the abstinence syndrome, and block the euphoric effects associated with opioids. Chronic methadone dosing will eventually lead to neuroadaptation, characterised by tolerance and dependence. However, when used correctly in treatment, maintenance therapy is medically safe, non-sedating, and can provide a slow recovery from opioid addiction. Methadone has been widely used for pregnant women addicted to opioids.
Copanlisib, sold under the brand name Aliqopa, is a medication used for the treatment of adults experiencing relapsed follicular lymphoma who have received at least two prior systemic therapies. In November 2023, Bayer announced that it was withdrawing copanlisib from the United States market after the drug's phase III trial, CHRONOS-4, failed to establish confirmation of clinical benefits as sought by the Food and Drug Administration.
Sources: en.wikipedia.org
On 4 June, Hezbollah rejected the truce deal announced the previous day and instead demanded a comprehensive truce and full withdrawal of Israel from Lebanon. On 19 June, an American official said that Israel and Hezbollah agreed to a truce mediated by the US, Qatar and Iran. On 26 June, US Secretary of State Marco Rubio announced a framework deal between Israel and Lebanon for "lasting peace and security" via US mediation. The agreement includes a cease-fire, requiring Hezbollah to end hostilities and withdraw from southern Lebanon, but it was subsequently rejected by Hezbollah.
Pholcus phalangioides, commonly known as the cosmopolitan cellar spider, long-bodied cellar spider, or one of various types called a daddy long-legs spider, is a spider of the family Pholcidae. It was first described in 1775 by the Swiss entomologist Johann Kaspar Füssli (his surname is also spelled Fuesslin) as Aranea phalangoides. Its common name of "daddy long-legs" should not be confused with a different arachnid group with the same common name, the harvestman (Opiliones), or the crane flies of the superfamily Tipuloidea. Females have a body length of about 8 mm while males tend to be slightly smaller. The length of the spider's legs are on average 5 or 6 times the length of its body. Pholcus phalangioides has a habit of living on the ceilings of rooms, caves, garages or cellars. This spider species is considered beneficial in parts of the world because it preys on other spiders, including species considered dangerous such as redback spiders. Pholcus phalangioides is known to be harmless to humans and a potential for the medicinal use of their silk has been reported.
=== Active site === The cleft between GALE's N- and C-terminal domains constitutes the enzyme's active site. A conserved Tyr-X-X-X Lys motif is necessary for GALE catalytic activity; in humans, this motif is represented by Tyr 157-Gly-Lys-Ser-Lys 161, while E. coli GALE contains Tyr 149-Gly-Lys-Ser-Lys 153. The size and shape of GALE's active site varies across species, allowing for variable GALE substrate specificity. Additionally, the conformation of the active site within a species-specific GALE is malleable; for instance, a bulky UDP-GlcNAc 2' N-acetyl group is accommodated within the human GALE active site by the rotation of the Asn 207 carboxamide side chain.
=== Inter-Tribal Environmental Council === Since 1992, the nation has served on Inter-Tribal Environmental Council. The mission of ITEC is to protect the health of Native Americans, their natural resources and their environment as it relates to air, land and water. To accomplish this mission, ITEC provides technical support, training, and environmental services in a variety of environmental disciplines.
Sources: en.wikipedia.org
No. Major drug regulators have not approved GW501516 for treating any medical condition. Products sold as cardarine are typically unapproved research chemicals or supplements, so their contents and safety are not assured.
It is prohibited by the World Anti-Doping Agency as a hormone and metabolic modulator. Athletes who test positive for GW501516 can face sanctions, including suspensions and loss of results.
Cardarine is a common or trade-style name, while GW501516 is the research code for the same chemical entity. Some sources also use Endurobol or GSK-516. The names refer to the same compound, not distinct drugs.
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.