This is a working overview of LC-MS/MS, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-22. Anything still debated is marked as such rather than presented as settled.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
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.
Detection of GW501516 in biological samples generally relies on liquid chromatography coupled with tandem mass spectrometry. Urine is a common matrix in anti-doping analysis, while blood or plasma may be used in research settings. Sample preparation can involve enzymatic hydrolysis, protein precipitation, or solid-phase extraction before instrumental analysis. Because the compound undergoes metabolism, assays may target the parent molecule, one or more metabolites, or both. Detection windows are not fixed; they depend on factors such as dose, route, individual metabolism, and assay sensitivity. Reference standards are required for accurate identification and quantification.
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.
| Property | Value | Notes |
|---|---|---|
| Primary target | PPARδ | Nuclear receptor; not androgen receptor |
| Studied indications | Dyslipidemia; obesity; diabetes | Early clinical research; development discontinued |
| Rodent toxicity | Tumor formation in multiple tissues | Dose-dependent findings in some studies |
| Human approval | None | No approved therapeutic use |
| Typical analytical method | LC-MS/MS | Used for identity and quantification |
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.
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.
Cardarine is a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
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.
==== Below 1% ==== There are few studies of the health effects of long-term continuous CO2 exposure on humans and animals at levels below 1%. Occupational CO2 exposure limits have been set in the United States at 0.5% (5000 ppm) for an eight-hour period. At this CO2 concentration, International Space Station crew experienced headaches, lethargy, mental slowness, emotional irritation, and sleep disruption. Studies in animals at 0.5% CO2 have demonstrated kidney calcification and bone loss after eight weeks of exposure. A study of humans exposed in 2.5 hour sessions demonstrated significant negative effects on cognitive abilities at concentrations as low as 0.1% (1000 ppm) CO2 likely due to CO2 induced increases in cerebral blood flow. Another study observed a decline in basic activity level and information usage at 1000 ppm, when compared to 500 ppm. However a review of the literature found that a reliable subset of studies on the phenomenon of carbon dioxide induced cognitive impairment to only show a small effect on high-level decision making (for concentrations below 5000 ppm). Most of the studies were confounded by inadequate study designs, environmental comfort, uncertainties in exposure doses and differing cognitive assessments used. Similarly a study on the effects of the concentration of CO2 in motorcycle helmets has been criticized for having dubious methodology in not noting the self-reports of motorcycle riders and taking measurements using mannequins.
== Taxonomy == The first scientific description of Vanilla planifolia was published by Henry Charles Andrews in the eighth volume of his The Botanist's Repository. In his description he credits Charles Plumier with publishing a description of it in 1703 as the third species of the genus Vanilla. Andrews created the drawing in his book from a specimen that bloomed in a hothouse belonging to Charles Greville.
== In culture == Although observations of soy consumption inducing gynecomastia on men are not conclusive, a pejorative term, "soy boy", has emerged to describe perceived emasculated young men with feminine traits.
=== Israel and Palestine === In August 2024, The Times of Israel reported that Pritzker previously served on the national board of the pro-Israel lobby group AIPAC. In March 2026, Pritzker clarified to The New York Times that while he had donated to AIPAC, he had not served on its board. In 2026, he was described as a "former supporter" of the group and his spokesperson said he had not donated to AIPAC in a decade and believed the group had "abandoned its bipartisan principles and become a pro-Trump organization". After the October 7 attacks on Israel in 2023, Pritzker issued a public condemnation of the attacks, saying that Illinois "unequivocally stands" with the Israeli people and that Hamas is a terrorist organization while acknowledging that "There are many peace-loving Palestinians" in Gaza. In February 2024, Pritzker criticized the Gaza ceasefire resolution passed by Chicago Mayor Brandon Johnson and rejected calls for an immediate permanent ceasefire in the Gaza war, arguing that a lasting ceasefire was not possible while Hamas retained the ability to attack Israel. In October 2024, he publicly supported a ceasefire, saying, "It's past time to honor the innocent Palestinian and Israeli lives lost by securing the release of the hostages and implementing a ceasefire" in a statement on social media. In June 2025, Pritzker said the question of whether what is happening in Gaza is a genocide was for others to determine in accordance with the term's definition.
Sources: en.wikipedia.org
The Government of India refused the offer from Union Carbide, and claimed US$3.3 billion. The Indian Supreme Court told both sides to come to an agreement and "start with a clean slate" in November 1988. Eventually, in an out-of-court settlement reached in February 1989, Union Carbide agreed to pay US$470 million for damages caused in the Bhopal disaster. The amount was immediately paid. Throughout 1990, the Indian Supreme Court heard appeals against the settlement. In October 1991, the Court upheld the original $470 million, dismissing any other outstanding petitions that challenged the original decision. It ordered the Indian government "to purchase, out of settlement fund, a group medical insurance policy to cover 100,000 persons who may later develop symptoms" and cover any shortfall in the settlement fund. It also requested UCC and its subsidiary UCIL "voluntarily" fund a hospital in Bhopal, at an estimated $17 million, to specifically treat victims of the Bhopal disaster. The company agreed to this.
E3 enzymes possess one of two domains: the homologous to the E6-AP carboxyl terminus (HECT) domain and the really interesting new gene (RING) domain (or the closely related U-box domain). HECT domain E3s transiently bind ubiquitin in this process (an obligate thioester intermediate is formed with the active-site cysteine of the E3), whereas RING domain E3s catalyse the direct transfer from the E2 enzyme to the substrate. The anaphase-promoting complex (APC) and the SCF complex (for Skp1-Cullin-F-box protein complex) are two examples of multi-subunit E3s involved in recognition and ubiquitylation of specific target proteins for degradation by the proteasome. In the ubiquitylation cascade, E1 can bind with many E2s, which can bind with hundreds of E3s in a hierarchical way. Having levels within the cascade allows tight regulation of the ubiquitylation machinery. Other ubiquitin-like proteins (UBLs) are also modified via the E1–E2–E3 cascade, although variations in these systems do exist. E4 enzymes, or ubiquitin-chain elongation factors, are capable of adding pre-formed polyubiquitin chains to substrate proteins. For example, multiple monoubiquitylation of the tumor suppressor p53 by Mdm2 can be followed by addition of a polyubiquitin chain using p300 and CBP. Some proteins contain extended lysine-free regions, known as lysine deserts, which have been studied as features that may limit lysine-directed ubiquitination while still allowing other forms of ubiquitin-dependent regulation.
== Leadership == Phil Keiser became the second CEO of the franchise in June 2015 until his death in October 2016. Joe Koss followed him in January 2017 until retiring at the end of 2020. He was succeeded by Enrique "Rick" Silva in March 2021. Silva retired in April 2025 and was replaced with Julie Fussner, the first female CEO of the company. She was previously the chief marketing officer, and had been with the company since 2017.
Sources: en.wikipedia.org
However the stepwise addition of at least three independent sets of chemical moieties to a tri-functional core building block for the construction and encoding of a very large DNA-encoded library (comprising up to 106 compounds) can also be envisaged.(Fig.2)
Heroin, the common name for diacetylmorphine, is the first of several semi-synthetic opioids to be derived from morphine, a component of natural opium. It is formed by the acetylation of morphine in order to increase the lipid solubility. Heroin (diacetylmorphine) is a morphine prodrug; it is metabolized by the liver into morphine after administration. One of the major metabolites of heroin, 6-monoacetylmorphine (6-MAM), is also a morphine prodrug.
Tifluadom is a benzodiazepine derivative with an unusual activity profile. Unlike most benzodiazepines, tifluadom has no activity at the GABAA receptor, but instead is a selective agonist for the κ-opioid receptor. It has potent analgesic and diuretic effects in animals, and also has sedative effects and stimulates appetite. While tifluadom has several effects which might have potential uses in medicine, such as analgesia and appetite stimulation, κ-opioid agonists tend to produce undesirable effects in humans such as dysphoria and hallucinations, and so these drugs tend to only be used in scientific research. Dysphoric effects are similar to those seen when using other κ-opioid receptor agonists like pentazocine and salvinorin A, and can be considered the opposite of morphine-induced euphoria. As such, kappa agonists are believed to have very limited abuse potential.
Sources: en.wikipedia.org
It targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not act primarily on androgen receptors. This distinction separates it from SARMs.
Rodent studies found dose-dependent tumors in several organs. The sponsor discontinued the program over cancer concerns. Human risk from long-term use remains unknown.
Controlled human endurance trials are lacking. Animal studies show increased exercise capacity under some conditions. Anecdotal reports are not equivalent to clinical evidence.
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.