This is a working overview of PPARδ agonist, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-06-28 and is reviewed periodically as new material appears.
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.
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.
Cardarine is a common name for GW501516, a synthetic compound studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Common for reference-grade material. |
| Solubility | Low in water | Dissolves in DMSO and some organic solvents. |
| Typical storage | -20 °C, desiccated | Protect from light and moisture. |
| Analytical method | LC-MS/MS | Used for trace detection in biological matrices. |
| Purity assessment | HPLC with UV detection | Often combined with NMR and mass spectrometry. |
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 explicitly prohibited by the World Anti-Doping Agency under the class of PPARδ agonists. Its presence in urine or blood samples can be detected using mass spectrometry-based methods, often liquid chromatography-tandem mass spectrometry. Athletes who test positive may face sanctions, including bans from competition. The compound is also regulated as a prescription-only or unapproved drug in many countries. Enforcement varies by jurisdiction, and some regions treat it as a controlled substance. Online sales may occur despite these restrictions, creating quality and legal risks.
Laboratory detection of cardarine typically involves sample preparation followed by chromatographic separation and mass spectrometric identification. Urine is the most common matrix for anti-doping tests, though blood and hair have also been explored. Methods can target the parent compound or its metabolites, depending on the expected window of detection. Reference standards are required for accurate quantification. Matrix effects and dilution can influence results, so laboratories use internal standards and validation protocols. The exact detection window varies with dose, route, and individual metabolism.
A common misconception is that cardarine has been proven safe for human use. In reality, human clinical data are limited, and long-term animal studies have raised concerns about cancer. Another misconception is that it is a supplement or vitamin-like compound. It is a synthetic research chemical with no approved medical indication. Scientific discussion often focuses on its mechanism and detection rather than therapeutic use. Regulatory and anti-doping literature treats it primarily as a prohibited substance.
=== Modern reception === Bloodlines is considered a cult classic. Retrospective critiques continue to praise the game's narrative and degree of choice. In 2009, an article in Rock, Paper, Shotgun declared: "The sense of sorrow comes from the realization that there's nothing like [Bloodlines] on the horizon ... why should there be so few games like this? Oh right, because it's so very hard to do ... the lack of games comparable to Bloodlines is one of the great tragedies of our time." Eurogamer called the game inspirational, with an unmatched level of narrative detail. In 2010, The Escapist called Bloodlines a flawed masterpiece which could have been a genuine masterpiece with more time, money, and staff; although great games may inspire awe, it instead created a devoted fan base which continued to develop the game. In 2006, PC Zone listed Bloodlines the seventh-best PC game which people were unlikely to have played, calling it the "best buggy game ever released". In 2007, the game was 80th on Computer & Video Games' list of its top 100 games, and 86th on PC Gamer's 2014 list of the same; it also appeared in PC Gamer's 2015 edition (moving to 63rd), 2017 edition (moving to 42nd), and 2021 edition (moving to 93rd). In 2008, bit-tech listed Jeanette as the second-best non-player video game character. In 2011, Rock, Paper, Shotgun called Bloodlines one of the most important PC games of all time ("it signposts a direction to a future of games that we were denied"), listing it as one of the 122 Best PC Games Ever.
== Example case: bacterial plasmid subcloning == In this example, a gene from mammalian gene library will be subcloned into a bacterial plasmid (destination platform). The bacterial plasmid is a piece of circular DNA which contains regulatory elements allowing for the bacteria to produce a gene product (gene expression) if it is placed in the correct place in the plasmid. The production site is flanked by two restriction enzyme cutting sites "A" and "B" with incompatible sticky ends. The mammalian DNA does not come with these restriction sites, so they are built in by overlap extension PCR. The primers are designed to put the restriction sites carefully, so that the coding of the protein is in-frame, and a minimum of extra amino acids is implanted on either side of the protein. Both the PCR product containing the mammalian gene with the new restriction sites and the destination plasmid are subjected to restriction digestion, and the digest products are purified by gel electrophoresis. The digest products, now containing compatible sticky ends with each other (but incompatible sticky ends with themselves) are subjected to ligation, creating a new plasmid which contains the background elements of the original plasmid with a different insert. The plasmid is transformed into bacteria and the identity of the insert is confirmed by DNA sequencing.
=== London Fire Brigade === Brent has three fire stations: Park Royal, Wembley and Willesden. Brent has a mixture of residential, industrial and commercial land. Wembley National Stadium is in the borough; on match days the fire safety of over 90,000 people falls to the London Fire Brigade. The Wembley station covers the largest area in the borough, 19.1 km2 (7.4 sq mi). Two pumping appliances, a fire rescue unit and an aerial ladder platform are based there. Willesden, for its more typical area covered (10.5 km2 (4.1 sq mi)), responded to over a thousand incidents in 2006/2007. Two pumping appliances reside there. Park Royal, with its one pumping appliance and an incident response unit covers 8.1 km2 (3.1 sq mi). Within the borough, 4,105 incidents occurred in 2006/2007.
Sources: en.wikipedia.org
=== Functional analogues and derivatives === 3,3-Difluoroalanine: Difluorinated alanine with similar residue hydrophobicity to that of isoleucine. 3,3,3-Trifluoroalanine: Trifluorinated alanine that expresses properties of a suicide inhibitor for alanine racemases. 3,3,3-Trifluoroalanine N-carboxyanhydride: A cyclic anhydride of trifluorinated alanine investigated for use as a monomer in homo- and co-polymerisations.
=== Ukraine === The epidemic of HIV/AIDS in Ukraine is quickly growing and was the reason for research into opioid agonist therapies (OAT) in the country as a means to curb the spread of HIV. Ukraine has the highest rate of HIV in Europe at 1.2% and most of the spread of HIV in Ukraine is primarily through people who inject drugs and secondarily through these drug users sexual partners. In 2016, opioid agonist therapies were only being given to 2.7% of the 346,000 people who inject drugs in Ukraine. OAT utilized Buprenorphine starting in 2004 and Methadone in 2008. However, due to the cost of OAT, government regulation prohibits the number of patients that can receive such therapies at a time, meaning a new patient can enter only after another has left. From 2010 to 2013 this number patients remained at a ceiling of roughly 9,000 patients throughout the country. As of 2016 OAT for these 9,000 patients is being administered only by narcologists at 174 licensed treatment centers.
However, the concentrations were supraphysiological and the same may not be the case with more physiological concentrations. Cellular proliferation in the breasts is greatest in the luteal phase of the menstrual cycle, when progesterone levels are highest. It has been hypothesized that progestogens may counteract various effects of estrogens in the brain such as stimulatory and excitatory effects on neuronal activity. Progesterone moreover has a special position among progestogens concerning such actions due to its inhibitory neurosteroid metabolites and their central depressant effects. It has been suggested that these actions of progestogens may explain unfavorable effects on mood that have been reported with these medications in some women. However, the mutual interactions of estrogens and progestogens in the brain in general are controversial and require more research. Progesterone can produce body-wide antiestrogenic effects at very high doses in both women and men via its antigonadotropic effects and consequent suppression of gonadal estrogen production (see below). These antigonadotropic effects are mediated by hyperactivation of the PR.
== Further reading == Merck Sharp and Dohme Corporation (22 May 2013). "Suvorexant Advisory Committee Meeting Briefing Document: Peripheral & Central Nervous System Drugs Advisory Committee Meeting" (PDF). Food and Drug Administration. Archived from the original (PDF) on 12 June 2013. Dimova H, Brar S, Men A (2014). "Application Number: 204569Orig1s000. Clinical Pharmacology/Biopharmaceutics Review. Suvorexant (MK-4305)" (PDF). Center for Drug Evaluation and Research (Food and Drug Administration). Archived from the original (PDF) on 5 March 2022.
Sources: en.wikipedia.org
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.
Reference material is usually kept cold, dry, and protected from light. Frozen aliquots reduce repeated freeze-thaw cycles.
No approved pharmaceutical product exists, so manufacturing and quality controls are not standardized. Products may contain different compounds or impurities.
Cardarine is a common name for GW501516, a synthetic PPARδ agonist. It is not a steroid or a selective androgen receptor modulator. It was developed and studied as a research compound for metabolic pathways.