Everything below concerns LC-MS/MS. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-01-19. Numbers and descriptions here follow the published literature rather than marketing 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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular target | PPAR delta (NR1C2) | Ligand-activated nuclear receptor. |
| Primary tissues studied | Skeletal muscle, liver, adipose | Effects on fatty acid oxidation and energy use. |
| Typical detection matrix | Urine | Used in anti-doping analysis. |
| Common analytical method | LC-MS/MS | Detects parent compound and metabolites. |
| Sport regulatory class | Prohibited at all times | Listed as a metabolic modulator by WADA. |
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.
Laboratory handling focuses on identity, purity, and stability. Reference standards are typically stored cold and dry, protected from light, because solutions can degrade over time. Analytical checks may use high-performance liquid chromatography with ultraviolet detection or mass spectrometry. Impurities and related substances can be separated chromatographically and compared with a known standard. Because cardarine is not an approved drug, compendial monographs are absent, and laboratories often rely on in-house methods. Reported purity varies among unregulated products and should not be assumed from a label.
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.
Handling and quality assessment of cardarine reference material follow general laboratory practices for poorly characterized compounds. It typically appears as a white to off-white powder and is sparingly soluble in water but soluble in organic solvents such as dimethyl sulfoxide and ethanol. Storage recommendations usually specify a cool, dry, dark place, with long-term storage at low temperature and desiccation. Purity may be checked by high-performance liquid chromatography with ultraviolet detection, while identity is confirmed by mass spectrometry and nuclear magnetic resonance. No pharmacopeial monograph exists, so reported purity and stability depend on the supplier’s methods.
GW501516 acts as a selective agonist at PPARδ, a nuclear receptor that regulates transcription of genes involved in lipid handling and energy metabolism. Activation of PPARδ in preclinical models increases fatty acid oxidation, mitochondrial biogenesis, and exercise endurance in rodents. These effects have made the compound a subject of metabolic research and also a target for sport anti-doping rules. In humans, however, controlled studies are limited, and whether similar endurance or metabolic changes occur at tolerated exposures remains an open question. The receptor’s broad tissue distribution also means downstream effects may vary by organ and condition.
Sporting authorities added GW501516 to prohibited lists after it appeared in athlete samples and online markets. The World Anti-Doping Agency classifies it as a hormone and metabolic modulator, and its use can lead to an anti-doping rule violation. Some early laboratory work suggested effects on fatty acid oxidation and endurance-related metabolism in animals, but those findings do not establish safe or effective use in people. Reports of adverse events in humans are scarce and often anecdotal, which complicates risk assessment.
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.
Trans fats occur in meat and dairy products from ruminants. For example, butter contains about 3% trans fat by weight. These naturally occurring trans fats include conjugated linoleic acid (CLA) and vaccenic acid (trans-11 18:1). They arise from the action of bacteria in the rumen. Polyunsaturated fats are toxic to the rumen-based bacteria, which detoxify the fats by changing some cis-double bonds to trans-double bonds. In contrast to industrially produced trans fats, this bacterial process produces only a few specific isomers. Conjugated trans fatty acids such as CLA are exempt from counting as trans fat in the US. The Codex Alimentarius includes an analogous exclusion. As industrial sources of trans fats are eliminated, increased attention focuses on ruminant derived trans fats. Not all ruminant-derived trans fats are innocuous like vaccenic acid and its metabolite rumenic acid (cis-9-trans-11 CLA / 18:2). In particular, trans-10 18:1 is not turned into a conjugated linoleic acid by humans. It appears to have health consequences comparable to trans fats of industrial origin.
However, later on, within a more complex cellular environment, these highly hydrophobic LCRs became inappropriate or even toxic from a protein interaction perspective and have been selected against ever since. In addition, they further hypothesize that the very early protopeptides did not have a nucleic acid binding role, because DNA and RNA-binding LCRs are highly enriched in glycine, arginine and lysine, however, arginine and lysine are not among the amino acids of the proposed early genetic code.
One of the most important events in the decade after the war was the creation of the Union of South Africa (later the Republic of South Africa). It proved a key ally to Britain as a Dominion of the British Empire during the World Wars. At the start of the First World War a crisis ensued when the South African government led by Louis Botha and other former Boer fighters, such as Jan Smuts, declared support for Britain and agreed to send troops to take over the German colony of German South-West Africa (Namibia). Many Boers were opposed to fighting for Britain, especially against Germany, which had been sympathetic to their struggle. Some bittereinders and their allies took part in a revolt known as the Maritz rebellion. The rebellion was quickly suppressed, and the leading Boer rebels escaped lightly (especially compared with leading Irish rebels of the Easter Rising), with imprisonment of 6-7 years and heavy fines. Two years later, they were released from prison, as Louis Botha recognised the value of reconciliation.
An mRNA vaccine (or RNA vaccine) is a novel type of vaccine which is composed of the nucleic acid RNA, packaged within a vector such as lipid nanoparticles. Among the COVID-19 vaccines are a number of RNA vaccines to combat the COVID-19 pandemic and some have been approved or have received emergency use authorization in some countries. For example, the Pfizer-BioNTech vaccine and Moderna mRNA vaccine are approved for use in adults and children in the US.
=== Sexual === Cnidarian sexual reproduction often involves a complex life cycle with both polyp and medusa stages. For example, in Scyphozoa (jellyfish) and Cubozoa (box jellies), a larva swims until it finds a good site, and then becomes a polyp. This grows normally but then absorbs its tentacles and splits horizontally into a series of disks that become juvenile medusae, a process called strobilation. The juveniles swim off and slowly grow to maturity, while the polyp re-grows and may continue strobilating periodically. The adult medusae have gonads in the gastroderm, and these release ova and sperm into the water in the breeding season. This phenomenon of succession of differently organized generations (one asexually reproducing, sessile polyp, followed by a free-swimming medusa or a sessile polyp that reproduces sexually) is sometimes called "alternation of asexual and sexual phases" or "metagenesis", but should not be confused with the alternation of generations as found in plants. Shortened forms of this life cycle are common, for example some oceanic scyphozoans omit the polyp stage completely, and cubozoan polyps produce only one medusa. Hydrozoa have a variety of life cycles. Some have no polyp stages and some (e.g. hydra) have no medusae. In some species, the medusae remain attached to the polyp and are responsible for sexual reproduction; in extreme cases these reproductive zooids may not look much like medusae.
Sources: en.wikipedia.org
== Research == Much of Limbird's research has explored the activity of G-protein coupled receptors. She has demonstrated how alpha-2 adrenergic receptors are involved in regulation of blood pressure, suppression of pain, sedation and the action of opioid drugs. She has developed techniques for selectively manipulating such receptors. Limbird is the author of Cell Surface Receptors: A Short Course in Theory and Methods (1985, 1996, 2004); co-editor with Joel Hardman of the 9th (1995) and 10th (2001) editions of Goodman and Gilman’s Pharmacological Basis of Therapeutics; editor of Alpha2-Adrenergic Receptors (1988) and co-editor with Stephen Lanier of α2-Adrenergic Receptors. Structure, Function and Therapeutic Implications (1996). Limbird has served on the editorial boards of the Journal of Biological Chemistry, the American Journal of Physiology, and Molecular Pharmacology.
Anne-Claude Gingras is a senior investigator at Lunenfeld-Tanenbaum Research Institute, and a professor in the department of molecular genetics at the University of Toronto. She is an expert in mass spectrometry based proteomics technology that allows identification and quantification of protein from various biological samples. Gingras was born on Île d'Orléans, Quebec. She earned her undergraduate degree at Université Laval in Quebec. She completed her PhD in biochemistry at McGill University in Montreal, studying how 4E-BP1 regulated translation initiation, under the mentorship of Nahum Sonenberg. After graduating in 2001, she began postdoctoral research in Seattle at the Institute for Systems Biology in the lab of Ruedi Aebersold, where she studied proteomics for three years. In 2005, Gingras moved to Toronto and joined the Lunenfeld-Tanenbaum Research Institute, and in 2006, she began teaching at the University of Toronto in the department of molecular genetics.
2 Bh + 3 O2 + 2 HCl → 2 BhO3Cl + H2 The longer-lived heavy isotopes of bohrium, produced as the daughters of heavier elements, offer advantages for future radiochemical experiments. Although the heavy isotope 274Bh requires a rare and highly radioactive berkelium target for its production, the isotopes 272Bh, 271Bh, and 270Bh can be readily produced as daughters of more easily produced moscovium and nihonium isotopes.
== Marketing == Ipragliflozin was the first drug of its kind sold by any company in Japan. Therefore, Astellas will focus their marketing in order to maintain the top share of this market that it holds. Astellas has been building up post-marketing data in regard to the efficacy and safety of ipragliflozin. By supplying information based on this data, Astellas aims to increase the market penetration of ipragliflozin in the Japanese market. In 2015, Astellas additionally launched Suglat in the Republic of Korea and Feburic in Thailand.
Sources: en.wikipedia.org
== Hypothermia == Reduced body temperature, or therapeutic hypothermia, during clinical death slows the rate of injury accumulation, and extends the time period during which clinical death can be survived. The decrease in the rate of injury can be approximated by the Q10 rule, which states that the rate of biochemical reactions decreases by a factor of two for every 10 °C reduction in temperature. As a result, humans can sometimes survive periods of clinical death exceeding one hour at temperatures below 20 °C. The prognosis is improved if clinical death is caused by hypothermia rather than occurring prior to it; in 1999, 29-year-old Swedish woman Anna Bågenholm spent 80 minutes trapped in ice and survived with a near full recovery from a 13.7 °C core body temperature. It is said in emergency medicine that "nobody is dead until they are warm and dead." In animal studies, up to three hours of clinical death can be survived at temperatures near 0 °C.
=== Resolving power definition === Some mass spectrometrists use the definition that is similar to definitions used in some other fields of physics and chemistry. In this case, resolving power is defined as:
== External links == "Terracotta Is a 3,000-Year-Old Solution to Fighting Extreme Heat". Scientific American. - uses of terracotta for refrigeration Green Cooling Initiative, on alternative natural refrigerants cooling technologies "The Refrigeration Cycle" at HowStuffWorks "The Refrigeration". frigokey.com.tr. Archived from the original on March 20, 2017. American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) International Institute of Refrigeration (IIR) British Institute of Refrigeration Scroll down to "Continuous-Cycle Absorption System" US Department of Energy: Technology Basics of Absorption Cycles Institute of Refrigeration
In Taiwan, researchers were able to produce kefir in a laboratory using microorganisms isolated from kefir grains. They report that the resulting kefir drink had chemical properties similar to homemade kefir.
Once taken up by peripheral tissue cells, the major usage of absorbed β-carotene is as a precursor to retinal via symmetric cleavage by the enzyme beta-carotene 15,15'-dioxygenase, which is encoded by the BCO1 gene. A lesser amount is metabolized by the mitochondrial enzyme beta-carotene 9',10'-dioxygenase, which is encoded by the BCO2 gene. The products of this asymmetric cleavage are two beta-ionone molecules and rosafluene. BCO2 appears to be involved in preventing excessive accumulation of carotenoids; a BCO2 defect in chickens results in yellow skin color due to accumulation in subcutaneous fat.
Sources: en.wikipedia.org
It binds to and activates PPAR delta, a nuclear receptor that controls expression of genes related to fatty acid oxidation. This mechanism can alter energy metabolism in animal models. It is not a direct stimulant or fat-burning enzyme.
Early-stage trials examined lipid and glucose markers, but the development program was discontinued. Published human results are limited and do not support approved use for any indication. Claims of performance or health benefits remain unproven.
Yes. Laboratories use LC-MS/MS to detect GW501516 and its metabolites in urine. Detection depends on timing and sensitivity, but the substance is banned at all times.
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.