This is a working overview of PPAR delta, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-05-22 and is reviewed periodically as new material appears.
GW501516 acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in transcription of genes related to lipid handling and energy use. Activation of PPARδ can shift skeletal muscle toward greater fatty acid oxidation in animal models, which is one reason it drew interest for metabolic disease and exercise research. The exact downstream effects depend on tissue, species, dose, and duration. Human data are sparse, so many proposed benefits remain hypotheses rather than established clinical outcomes.
Laboratory studies have examined GW501516 in cell cultures and rodents for conditions such as dyslipidemia, insulin resistance, and obesity. Some trials in humans were initiated, but development was discontinued after preclinical findings raised concerns about cancer in certain models. Those findings do not prove that the compound causes cancer in people, but they contributed to regulatory caution. Later reviews often describe the evidence as preliminary and insufficient for assessing long-term safety.
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.
| Property | Value | Notes |
|---|---|---|
| Solubility | Soluble in dimethyl sulfoxide and some organic solvents; practically insoluble in water | Solvent choice affects laboratory handling |
| Typical storage | -20 °C, desiccated, protected from light | Common condition for research samples |
| Analytical method | Liquid chromatography–tandem mass spectrometry (LC-MS/MS) | Used for identification and quantification in biological or product samples |
| Common synonyms | GW501516, GW-501516, GSK-516, Endurobol | Names found in research and anti-doping literature |
| Regulatory status | Unapproved therapeutic; prohibited in competitive sport | Status can vary by country and context |
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.
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.
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.
So far, no known necrotoxins have been isolated from the venom of any of these spiders, and some arachnologists have disputed the accuracy of spider identifications carried out by bite victims, family members, medical responders, and other non-experts in arachnology. There have been several studies questioning the danger posed by some of the other spiders mentioned: In these studies, scientists examined case studies of bites in which the spider in question was identified by an expert, and found that the incidence of necrotic injury diminished significantly when "questionable" identifications were excluded from the sample set.
== Structure == In humans, the gene for StAR is located on chromosome 8p11.23 and the protein has 285 amino acids. The signal sequence of StAR that targets it to the mitochondria is clipped off in two steps with import into the mitochondria. Phosphorylation at the serine at position 195 increases its activity. The domain of StAR important for promoting cholesterol transfer is the StAR-related transfer domain (START domain). StAR is the prototypic member of the START domain family of proteins and is thus also known as STARD1 for "START domain-containing protein 1". It is hypothesized that the START domain forms a pocket in StAR that binds single cholesterol molecules for delivery to P450scc. The closest homolog to StAR is MLN64 (STARD3). Together they comprise the StarD1/D3 subfamily of START domain-containing proteins.
=== In humans === By the age of 4, all notochord residue is replaced by a population of chondrocyte-like cells of unclear origin. Persistence of notochordal cells within the vertebra may cause a pathologic condition: persistent notochordal canal. If the notochord and the nasopharynx do not separate properly during embryonic development, a depression (Tornwaldt bursa) or Tornwaldt cyst may form. The cells are the likely precursors to a rare cancer called chordoma.
Sources: en.wikipedia.org
Aryl nitriles can be synthesized via the Sandmeyer reaction of diazonium salts with copper(I) cyanide or by the Rosenmund-von Braun reaction (direct reaction of an aryl bromide with copper(I) cyanide). Conversion of thiocyanate with aromatic carboxylic acids, known as Letts nitrile synthesis, can be carried out using potassium thiocyanate; lead thiocyanate generally provides higher yields. Aryl iodides can be converted into aromatic nitriles under palladium catalysis with trimethylsilyl cyanide. For example, iodobenzene reacts with trimethylsilyl cyanide in the presence of tetrakis(triphenylphosphine)palladium(0) (Pd(PPh3)4) to form benzonitrile. Another palladium-catalyzed route (also employing Pd(PPh3)4) is the decarbonylation of aromatic acyl cyanides. Palladium-catalyzed cyanation of aryl chlorides with potassium cyanide or potassium hexacyanidoferrate(II) has likewise been reported. Quinones can react with trimethylsilyl cyanide to give silylated cyanohydrins, which are subsequently aromatized using phosphorus tribromide. A further approach involves reaction of aryl Grignard or aryllithium reagents with dimethylmalonitrile. Aromatic nitriles are often prepared in the laboratory from the aniline via diazonium compounds. This is the Sandmeyer reaction. It requires transition metal cyanides.
== Justification == Topical drug delivery is a route of administering drugs via the skin with the intent to provide therapeutic effects. This system usually provides a local effect on certain organs. In ancient times, people used herbs on wounds for relieving the inflammatory effect or as pain relievers. There are numerous dosage forms that can be used topically, including cream, ointment, lotion, patches, and other forms. The topical use has many advantages: avoiding first pass metabolism which can increase its bioavailability, being convenient and easy to apply to a large area, being easy to terminate the medication, and avoiding gastrointestinal irritations. All these can increase patient compliance. However, there are several disadvantages to this system – causing skin irritations and symptoms like rashes and itchiness may occur. Also, only small particles can pass through the skin, which limits the choice of drugs. Since skin is the main medium of the topical drug delivery system, its conditions determine the rate of skin penetration leading to affecting the pharmacokinetics of the drug. The temperature, pH value, and dryness of the skin need to be considered. There are some novel topical drugs in the market which can utilise the system as much as possible. This localized system provides topical therapeutic effects via skin, eyes, nose, and vagina to treat diseases. The most common usage is for local skin infections.
==== Horticulture ==== Some horticulturists and users of hydroponics advocate the use of weak hydrogen peroxide solution in watering solutions. Its spontaneous decomposition releases oxygen that enhances a plant's root development and helps to treat root rot (cellular root death due to lack of oxygen) and a variety of other pests. For general watering concentrations, around 0.1% is in use. This can be increased up to one percent for antifungal actions. Tests show that plant foliage can safely tolerate concentrations up to 3%.
The structure of chitin was determined by Albert Hofmann in 1929. Hofmann hydrolyzed chitin using a crude preparation of the enzyme chitinase, which he obtained from the snail Helix pomatia. Chitin is a modified polysaccharide that contains nitrogen; it is synthesized from units of N-acetyl-D-glucosamine (to be precise, 2-(acetylamino)-2-deoxy-D-glucose). These units form covalent β-(1→4)-linkages (like the linkages between glucose units forming cellulose). Therefore, chitin may be described as cellulose with one hydroxyl group on each monomer replaced with an acetyl amine group. This allows for increased hydrogen bonding between adjacent polymers, giving the chitin-polymer matrix increased strength. In its pure, unmodified form, chitin is translucent, pliable, resilient, and quite tough. In most arthropods, however, it is often modified, occurring largely as a component of composite materials, such as in sclerotin, a tanned proteinaceous matrix, which forms much of the exoskeleton of insects. Combined with calcium carbonate, as in the shells of crustaceans and molluscs, chitin produces a much stronger composite. This composite material is much harder and stiffer than pure chitin, and is tougher and less brittle than pure calcium carbonate. Another difference between pure and composite forms can be seen by comparing the flexible body wall of a caterpillar (mainly chitin) to the stiff, light elytron of a beetle (containing a large proportion of sclerotin).
Sources: en.wikipedia.org
=== Reaction === The peptide to be sequenced is adsorbed onto a solid surface. One common substrate is glass fibre coated with polybrene, a cationic polymer. The Edman reagent, phenylisothiocyanate (PITC), is added to the adsorbed peptide, together with a mildly basic buffer solution of 12% trimethylamine. This reacts with the amine group of the N-terminal amino acid. The terminal amino acid can then be selectively detached by the addition of anhydrous acid. The derivative then isomerises to give a substituted phenylthiohydantoin, which can be washed off and identified by chromatography, and the cycle can be repeated. The efficiency of each step is about 98%, which allows about 50 amino acids to be reliably determined.
It was the only instrument in use around 1930, but it was not widely accepted in medical circles. Treatment of acne with ultraviolet radiation is still controversial. Although UV radiation can have an antibacterial effect, it can also induce proliferative hyperkeratosis. This can lead to the formation of comedones ("blackheads"). Phototoxic effects may also occur. In addition, it is carcinogenic and promotes skin aging. UV therapy is increasingly being abandoned in favor of photodynamic therapy.
== Subsidiaries == Following declining earnings in 1965, HVEC reorganized into profit centers and established three wholly owned subsidiaries to diversify beyond particle accelerators. After U.S. orders for new accelerators ceased in the early 1970s, HVEC transformed into a miniconglomerate with more than ten subsidiaries, and industrial products from these units accounted for 80 percent of company revenues by 1972.
Giant was founded in 1944 as a small grocery store in Kuala Lumpur and expanded with the opening of the Teng Minimarket Centre (TMC) in Bangsar in 1974. In 1999, Dairy Farm International Holdings bought a 90% interest in the chain, with the Teng family retaining the balance. By 2003, the holding company for the chain had changed its name to Dairy Farm Giant Retail Sdn Bhd, and the chain had eight Giant hypermarkets and 10 supermarkets as well as three Cold Storage supermarkets. Later, the company operated as a subsidiary of Dairy Farm International Holdings Limited and the name was changed to GCH Retail (Malaysia) Sdn Bhd. GCH Retail was 30%-owned by Syarikat Pesaka Antah Sdn Bhd — a company controlled by the Negeri Sembilan royal family and balance 70% by DFI Mauritius Ltd. In December 2011, Giant expanded into Vietnam. However, in February 2018, the Group disposed of its 100% interest in Asia Investment Supermarket Trading Co. Ltd. (AISTC), operating a hypermarket in Vietnam to Auchan Retail Vietnam, for net cash inflow of US$6.4 million. As such, the Group has exited from supermarket and hypermarket business in Vietnam. Beginning 2017, Giant and its peers in the hypermarket retail segment in Malaysia had been underperforming due to high operational costs, weakening consumer spending, and stiffer competition from smaller supermarkets, retailers and e-commerce. In 2019, it closed at least six outlets in Peninsular Malaysia operations. It comprises 2 hypermarkets and 2 Cold Storage outlets in Selangor, 1 each in Kedah, Perak, and Kuala Lumpur.
The United States Armed Forces' Meal, Ready-to-Eat (MRE) is packaged similarly to the Canadian ration. Each sealed plastic bag contains one entire precooked meal, with a number of supplements and accessories. The original 12 menus have been expanded to 24 and now contain a variety of ethnic and special request items as well. Kosher/Halal and Vegetarian menus are also provided. Each meal bag contains an 8-ounce (230 g) main course (packaged in a four-layer plastic and foil laminate retort pouch), 8 hardtack crackers, some form of spread (cheese, peanut butter, or jelly), a fruit-based beverage powder, some form of dessert (cake, candy, cookies, or fruit), and an accessory packet containing coffee or tea, creamer, sugar, salt, matches, a plastic spoon, and toilet paper. A chemical heater is packed with every meal. The First Strike Ration (FSR) is a compact, eat-on-the-move ration to be used for no more than three days during initial periods of highly intense, highly mobile combat assaults. A single FSR (24 hours food) is about 50% of the size and weight of three MREs. Each FSR provides 2,900 kcal (12,000 kJ) (15% protein, 53% carbohydrates, 34% fat), versus the 3,800 kcal (16,000 kJ) in three MREs, and has a two-year shelf life when stored at 80 °F (27 °C).
Sources: en.wikipedia.org
It binds and activates PPARδ, a nuclear receptor that influences gene expression related to fatty acid metabolism and energy balance. This mechanism has been studied mainly in animals and cell models, not established as a safe human therapy.
No. It is not an anabolic-androgenic steroid; it is a synthetic PPARδ agonist. Because it is banned in sport, it is sometimes grouped with doping agents even though its chemical class differs from steroids.
Human data are limited and development was discontinued, so major effects and long-term risks are not well characterized. Some early studies examined metabolic markers, but they do not provide a basis for unsupervised use.
No. Cardarine has not received approval for human therapeutic use in major jurisdictions. It remains an investigational compound.