This is a working overview of PPARδ, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-07-28 and is reviewed periodically as new material appears.
Published studies have examined GW501516 in animal models of obesity, insulin resistance, and exercise endurance. Early human trials reportedly ended, and development was discontinued after preclinical findings raised concerns about cancer in some rodent studies. Regulatory agencies have not approved cardarine for any medical use. Its availability through non-pharmaceutical channels raises questions about identity, purity, and legal status that are separate from its laboratory pharmacology. Those questions are often addressed through analytical testing rather than assumptions about product labels.
Cardarine is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a drug.
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.
Laboratory detection of GW501516 commonly uses liquid chromatography coupled with tandem mass spectrometry. The method can identify the parent compound or its metabolites in urine and blood after sample cleanup. Protein precipitation, solid-phase extraction, or enzymatic hydrolysis may precede analysis, depending on the matrix. Reference standards are required for accurate quantification and confirmation. Because the compound is not approved, testing often occurs in anti-doping, forensic, or research settings rather than routine clinical care. Results are reported with limits of detection and quantification.
| Property | Value | Notes |
|---|---|---|
| Chemical class | PPARδ agonist | Not an anabolic steroid. |
| Common synonyms | GW501516, GW-1516 | Cardarine is an informal name. |
| Appearance | White to off-white powder | Typical for research-grade solid. |
| Solubility class | Poorly soluble in water; soluble in some organic solvents | Such as DMSO or ethanol in laboratory settings. |
| Typical storage temperature | Cool, dry, protected from light | Specific conditions vary by supplier and form. |
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.
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.
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.
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.
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.
Type 1 diabetes Type 2 diabetes Hybrid forms of diabetes(including slowly evolving, immune-mediated diabetes of adults and ketosis-prone type 2 diabetes) Hyperglycemia first detected during pregnancy Other specific types Unclassified diabetes Diabetes is a more variable disease than once thought, and individuals may have a combination of forms.
In 1926, the Portway, a new road along the Avon Gorge built at a cost of around £800,000, was opened linking the floating harbour to the expanding docks at Avonmouth. As the location of aircraft manufacture and a major port, Bristol was a target of bombing during the Bristol Blitz of World War II. Bristol's city centre also suffered severe damage, especially in November and December 1940, when the Broadmead area was flattened, and Hitler claimed to have destroyed the city. The original central area, near the bridge and castle, is still a park featuring two bombed out churches and some fragments of the castle. Slightly to the north, the Broadmead shopping centre and Cabot Circus were built over bomb-damaged areas. About 1,300 people living or working in the city were killed, and nearly 100,000 buildings were damaged, at least 3,000 beyond repair. As with other British cities, there was immigration from various Commonwealth countries in the post war years, which did lead to some racist tension. In 1963, a colour bar operated by Bristol Omnibus Company, which at that time refused to employ Black or Asian bus crews, was successfully challenged in the Bristol Bus Boycott, which was considered to have been instrumental in the eventual passage of the Race Relations Act 1968. In 1980 a police raid on a cafe in St Paul's sparked the St Pauls riot, which highlighted the alienation of the city's ethnic minorities. Bristol aviation continued to develop in post war years.
A 2018 meta-analysis found no higher risk of breast cancer with 5α-reductase inhibitors. Sexual and mood side effects, such as erectile dysfunction, loss of libido, depression, and reduced semen volume occur in as many as 4.8% of patients taking 5α-reductase inhibitors including dutasteride. In affected men, semen volume is decreased an average of 30%, with a smaller subgroup of patients also experiencing a decrease of sperm motility of 6 to 12%. Sperm shape and function are unaffected and the impact on male fertility is unknown. These negative effects reverse by 3–4 months after discontinuation of the drug. In a study of 6,729 men with benign prostatic hyperplasia (BPH, a condition where the prostate grows unassociated with cancer), 9% had erectile dysfunction (compared to 5.7% treated with a placebo), 3.3% experienced decreased sex drive (vs 1.6% of placebo), and 1.9% had enlarged breasts (vs 1% of placebo). These effects were noted to resolve over time, with many fewer men reporting any adverse effects by the end of the 4-year study. The rate of discontinuation of the drug due to adverse effects was less than 5%. A subset of men affected by sexual and mood side effects report persistent loss of libido, depression, and erectile dysfunction for several years after discontinuing treatment.
=== Pharmaceuticals === Ion-exchange resins are used in the manufacturing of pharmaceuticals, not only for catalyzing certain reactions, but also for isolating and purifying pharmaceutical active ingredients. Three ion-exchange resins, sodium polystyrene sulfonate, colestipol, and cholestyramine, are used as active ingredients. Sodium polystyrene sulfonate is a strongly acidic ion-exchange resin and is used to treat hyperkalemia. Colestipol is a weakly basic ion-exchange resin and is used to treat hypercholesterolemia. Cholestyramine is a strongly basic ion-exchange resin and is also used to treat hypercholesterolemia. Colestipol and cholestyramine are known as bile acid sequestrants. Ion-exchange resins are also used as excipients in pharmaceutical formulations such as tablets, capsules, gums, and suspensions. In these uses the ion-exchange resin can have several different functions, including taste-masking, extended release, tablet disintegration, increased bioavailability, and improving the chemical stability of the active ingredients. Selective polymeric chelators have been proposed for maintenance therapy of some pathologies, where chronic ion accumulation occurs, such as Wilson disease (where copper accumulation occurs) or hereditary hemochromatosis (iron overload, where iron accumulation occurs) These polymers or particles have a negligible or null systemic biological availability and they are designed to form stable complexes with Fe2+ and Fe3+ in the GIT and thus limiting the uptake of these ions and their long-term accumulation.
Sources: en.wikipedia.org
== Disease and Pharmaceutical Relevance == While one study which utilized mice models indicated that acrosin is not a necessary component of zona pellucida penetration, other studies in humans have shown an association between low acrosomal proteinase activity and infertility. Other research groups have demonstrated a significant correlation between acrosin activity and sperm motility. In rabbit models, an intravaginal contraceptive device that secreted tetradecyl sodium sulfate, a known inhibitor of acrosin and hyaluronidases, had a complete contraceptive effect. Although its exact mechanism of action is not entirely clear, acrosin could thus serve as a novel target for contraceptive agents. Acrosin may represent as a uniquely druggable target due to its location and high cellular specificity. Thus, developing inhibitors of acrosin could provide the basis for safe, reversible male contraceptives, or female contraceptives through the use of intravaginal contraceptive devices. Moreover, as serine proteases are important in the potentiation of HIV, research has found that an acrosin inhibitor, 4'-acetamidophenyl 4-guanidinobenzoate, possess the ability to inhibit HIV infection in virus-inoculated lymphocytes. This suggests the further role of acrosin inhibitors as potentially viable agents in the prevention of HIV transmission.
In many periodic tables, the f-block is shifted one element to the right, so that lanthanum and actinium become d-block elements in group 3, and Ce–Lu and Th–Lr form the f-block. Thus the d-block is split into two very uneven portions. This is a holdover from early mistaken measurements of electron configurations; modern measurements are more consistent with the form with lutetium and lawrencium in group 3, and with La–Yb and Ac–No as the f-block. The 4f shell is completely filled at ytterbium, and for that reason Lev Landau and Evgeny Lifshitz in 1948 considered it incorrect to group lutetium as an f-block element. They did not yet take the step of removing lanthanum from the d-block as well, but Jun Kondō realized in 1963 that lanthanum's low-temperature superconductivity implied the activity of its 4f shell. In 1965, David C. Hamilton linked this observation to its position in the periodic table, and argued that the f-block should be composed of the elements La–Yb and Ac–No. Since then, physical, chemical, and electronic evidence has supported this assignment. The issue was brought to wide attention by William B. Jensen in 1982, and the reassignment of lutetium and lawrencium to group 3 was supported by IUPAC reports dating from 1988 (when the 1–18 group numbers were recommended) and 2021. The variation nonetheless still exists because most textbook writers are not aware of the issue.
==== Inexpensive method ==== The third and least expensive method the embalmers offered was to clear the intestines with an unnamed liquid, injected as an enema. The body was then placed in natron for seventy days and returned to the family. Herodotus gives no further details.
After pressure from the Department of Justice and after more than 1,000 churches said they would reopen, Newsom announced that churches would be allowed to open at 25% capacity. On April 9, 2021, the Supreme Court ruled against Newsom for a fifth and final time regarding his prohibitions and limits on religious gatherings. In a 5-4 decision, the court ruled that California unfairly singled out religious gatherings for restrictions and struck down the remaining restrictions on at-home religious gatherings. As the state opened up, the Los Angeles Times found that new coronavirus hospitalizations in California began accelerating around June 15 at a rate not seen since early April, immediately after the virus began rapidly spreading in the state. On June 18, Newsom made face coverings mandatory for all Californians in an effort to reduce COVID-19's spread. Enforcement was up to business owners, as local law enforcement agencies saw non-compliance as a minor infraction. By the end of June, Newsom had ordered seven counties to close bars and nightspots and recommended that eight other counties take action on their own to close those businesses due to a surge of coronavirus cases in parts of the state. In a regular press conference on July 13 as he was ordering the reinstatement of the shutdown of bars and indoor dining in restaurants, he said, "We're seeing an increase in the spread of the virus, so that's why it's incumbent upon all of us to recognize soberly that COVID-19 is not going away any time soon until there is a vaccine or an effective therapy".
Public healthcare in Hong Kong is recognized for its high-quality medical outcomes. The territory has the highest life expectancy in the world at 85.9 years. Hong Kong has one of the lowest infant mortality rates in the world, with recent estimates placing it around 1.7 to 2.5 deaths per 1,000 live births. However, the public system also faces challenges, including high patient volumes, overcrowding in emergency departments, and long wait times for specialist appointments and elective procedures. Healthcare in Hong Kong is provided through two categories, consisting of public and private hospitals. While private hospital services cater to patients seeking shorter wait times and personalized care, the majority of the population relies on the extensive public healthcare system. Public hospitals and clinics are heavily subsidized by the government, ensuring affordable access to a wide range of medical services. Hong Kong's healthcare system is managed primarily by the Hospital Authority, which was established in 1990 to oversee and operate all public hospitals in the region. The system is organized into seven geographic clusters that group hospitals and associated healthcare facilities based on their distribution across the territory. As of 2026, Hong Kong has a total of 42 public hospitals and 11 private hospitals.
Sources: en.wikipedia.org
Following a controversial constitutional amendment on 31 July 2025, the Legislative Assembly enabled indefinite reelection, extended presidential terms from five to six years, and eliminated the two-round system.
Computer Games Magazine argued the futility of reviewing the game due to its episodic nature; as the first part of a three-part story arc, it is difficult to judge it when divorced from the final product. Game Revolution expressed disappointment at a lack of new features such as environments and weapons. During the 10th Annual Interactive Achievement Awards, the Academy of Interactive Arts & Sciences nominated Half-Life 2: Episode One for "First-Person Action Game of the Year".
This enables the measurements of quadrupolar doublets for each nonequivalent deuterium atom. Thus reduces peak overlaps and provides more detailed information of hydrogen chemical environment. Mainstream uses of 2H-SNIF-NMR have been in source attribution, forensics and biosynthetic pathway studies. (See also Gray's section "Source attribution and Forensics") When measuring sugar compounds, a timesaving strategy is to convert them into ethanol through fermentation because 2H-SNIF NMR for ethanol is well established. Several studies have proved that hydrogen isotopes on the methyl and methylene position of the resulting ethanol is not affected by either fermentation rate or media. Another example is the study of monoterpenes. since the 1980s SNIF-NMR study of α-pinene has found large variations in DHR among its sites. Particularly ex-C2 position has a strong depletion (~-750‰), which was in disagreement with accepted biosynthetic mechanism (mevalonate mechanism) at that time, and lead to new development in pathways. More recently, Ina Ehlers published their work on the D6S/D6R ratios of glucose molecules. The stereochemical diteterium distribution was found to correlate to photorespiration/photosynthesis ratios. Photorespiration/photosynthesis ratios are driven by CO2 fertilization, thus this might lead to new proxies in reconstructing paleo-CO2 concentration.
HCl + NaHCO3 → NaCl + H2CO3 The carbonic acid rapidly equilibrates with carbon dioxide and water through catalysis by carbonic anhydrase enzymes bound to the gut epithelial lining, leading to a net release of carbon dioxide gas within the lumen associated with neutralisation. In the absorptive upper intestine, such as the duodenum, both the dissolved carbon dioxide and carbonic acid will tend to equilibrate with the blood, leading to most of the gas produced on neutralisation being exhaled through the lungs.
Proteins can coordinate metal ions on their surface and it is possible to separate proteins using chromatography by making use of the difference in their affinity to metal ions. This is termed as immobilized metal ion affinity chromatography (IMAC), as originally introduced in 1975 under the name metal chelate affinity chromatography. Subsequent studies have revealed that among amino acids constituting proteins, histidine is strongly involved in the coordination complex with metal ions. Therefore, if a number of histidines are added to the end of the protein, the affinity of the protein for the metal ion is increased and this can be exploited to selectively isolate the protein of interest. When a protein with a His-tag is brought into contact with a carrier on which a metal ion such as nickel is immobilized, the histidine residue chelates the metal ion and binds to the carrier. Since other proteins do not bind to the carrier or bind only very weakly, they can be removed by washing the carrier with an appropriate buffer. The poly-histidine tagged protein can then be recovered by eluting it off the resin.
Sources: en.wikipedia.org
Cardarine is commonly known as GW501516 or GW-1516. These names refer to the same synthetic compound. It is not a brand-name approved medicine.
No, cardarine is not a steroid. It is classified as a PPARδ agonist. Its structure and receptor target differ from anabolic steroids.
No regulatory agency has approved cardarine as a medicine. It was investigated in early research but development was discontinued. It is not available as a prescription drug.
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.