GW501516 is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-05-17. Numbers and descriptions here follow the published literature rather than marketing material.
Regulatory bodies treat GW501516 as a prohibited substance in competitive sport. The World Anti-Doping Agency added it to the prohibited list, and it falls under classes covering metabolic modulators and hormone-related agents. It is not approved by drug regulators for human use, and it is not a lawful dietary supplement. Products sold under the cardarine name may contain unlisted ingredients or different compounds. Because no approved product exists, quality and identity are not guaranteed by pharmaceutical manufacturing standards.
Cardarine is a common name for the investigational chemical GW501516, also written GW-1516. It was developed as a peroxisome proliferator-activated receptor delta agonist for metabolic conditions such as dyslipidemia. Early research focused on lipid handling and energy use in skeletal muscle and other tissues. The compound was never approved as a medicine. In public discussion, it is often grouped with performance-enhancing substances, although its receptor target differs from that of anabolic steroids or selective androgen receptor modulators. Regulatory and health authorities have issued warnings about its use.
GW501516 acts on PPARδ, a nuclear receptor that helps regulate fatty acid oxidation and energy homeostasis. In animal studies, activation of this receptor was associated with increased endurance and changes in lipid metabolism. Human trials examined effects on blood lipids and other metabolic markers, but the compound did not advance to approval. Rodent studies later reported tumors in multiple tissues at doses used in those experiments. Whether those findings translate to human risk remains uncertain, and the clinical relevance of the animal data is still debated.
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.
| Property | Value | Notes |
|---|---|---|
| Common name | Cardarine | Common internet and media name. |
| Research code | GW501516 | Also written GW-1516. |
| Drug class | PPARδ agonist | Not a selective androgen receptor modulator. |
| Development status | Discontinued | Clinical development halted after rodent cancer findings. |
| Regulatory status | Prohibited in sport | Listed by WADA; not approved as medicine. |
Anti-doping laboratories detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
Products sold as cardarine have been found to contain incorrect compounds, variable amounts, or no active ingredient at all. Independent testing is required to verify identity and purity. Common analytical approaches include high-performance liquid chromatography, mass spectrometry, and nuclear magnetic resonance for structural confirmation. These methods can distinguish GW501516 from related PPAR agonists and from unrelated steroids. For regulators and researchers, such verification is central to interpreting both biological results and adverse event reports.
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
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.
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.
Agonist of the μ-opioid receptor (MOR) and to a far lesser extent of the δ-opioid receptor (DOR) and κ-opioid receptor (KOR) Serotonin reuptake inhibitor (SRI) and norepinephrine reuptake inhibitor; hence, an SNRI Serotonin 5-HT2C receptor antagonist M1 and M3 muscarinic acetylcholine receptor antagonist α7 nicotinic acetylcholine receptor antagonist NMDA receptor antagonist (very weak) TRPA1 inhibitor Tramadol acts on the opioid receptors through its major active metabolite desmetramadol, which has as much as 700-fold higher affinity for the MOR relative to tramadol. Moreover, tramadol itself has been found to possess no efficacy in activating the MOR in functional activity assays, whereas desmetramadol activates the receptor with high intrinsic activity (Emax equal to that of morphine). As such, desmetramadol is exclusively responsible for the opioid effects of tramadol. Both tramadol and desmetramadol have pronounced selectivity for the MOR over the DOR and KOR in terms of binding affinity. Tramadol is well-established as an SRI. In addition, a few studies have found that it also acts as a serotonin releasing agent (1–10 μM), similar in effect to fenfluramine. The serotonin releasing effects of tramadol could be blocked by sufficiently high concentrations of the serotonin reuptake inhibitor 6-nitroquipazine, which is in accordance with other serotonin releasing agents such as fenfluramine and MDMA. However, two more recent studies failed to find a releasing effect of tramadol at respective concentrations up to 10 and 30 μM.
=== Cyclic peptides === Lin and her lab use computational chemistry to provide information on the solution structures of cyclic peptides. They recently successfully used molecular dynamics simulation with enhanced sampling methods to design well-structured cyclic peptides.
Interactive tutorial on mass spectra National High Magnetic Field Laboratory Mass spectrometer simulation An interactive application simulating the console of a mass spectrometer Realtime Mass Spectra simulation Tool to simulate mass spectra in the browser
The Ottomans, through the Ma'n dynasty, a great Druze feudal family, and the Shihabs, a mixed Sunni Muslim-Druze family that had converted to Christianity. Ma'n dynasty were a family of Druze chiefs of Arab stock based in the rugged Chouf area of southern Mount Lebanon who were politically prominent in the 15th–17th centuries. Deir al-Qamar was the capital and the residence of the Emirate of Mount Lebanon. The Church of Saidet et Tallé is a Maronite church in Deir el Qamar in Lebanon, it is one of the most important historical and religious sites in Deir el Qamar and dates to the 16th century. The second church was destroyed by the Saracens and rebuilt during Fakhreddine 1st Maan's (1518–1544) reign. In 1673, Sheikh Abu Fares Karam of Ehden (Emir Ahmad Ma'n's secretary) and his brother Sheikh Abu Nader enlarged the church and added a vault. During the reign of Bechir II Chehab (1789–1840) it was again enlarged and renovated. Fakhr-al-Din II (1572–1635) was a Druze prince and a leader of the Mount Lebanon Emirate. For uniting modern Lebanon's constituent parts and communities, especially the Druze and the Maronites, under a single authority for the first time in history, he is generally regarded as the country's founder. Christians prospered and played key roles under his rule, with his main enduring legacy being the symbiotic relationship he set in motion between Maronites and Druze, which proved foundational for the creation of a Lebanese entity. Maronite Abū Nādir al-Khāzin was one of his foremost supporters and served as Fakhr-al-Din's adjutant.
== Governmental regulation and promotion == Most countries place dietary supplements in a special category under the general umbrella of foods, not drugs. As a result, the manufacturer, and not the government, has the responsibility of ensuring that its dietary supplement products are safe before they are marketed. Regulation of supplements varies widely by country. In the United States, a dietary supplement is defined under the Dietary Supplement Health and Education Act of 1994. There is no FDA approval process for dietary supplements, and no requirement that manufacturers prove the safety or efficacy of supplements introduced before 1994. The Food and Drug Administration must rely on its Adverse Event Reporting System to monitor adverse events that occur with supplements. In 2007, the US Code of Federal Regulations (CFR) Title 21, part III took effect, regulating Good Manufacturing Practices (GMPs) in the manufacturing, packaging, labeling, or holding operations for dietary supplements. Even though product registration is not required, these regulations mandate production and quality control standards (including testing for identity, purity and adulterations) for dietary supplements. In the United States, the United States Pharmacopeia (USP) sets standards for the most commonly used vitamins and preparations thereof. Likewise, monographs of the European Pharmacopoeia (Ph.Eur.) regulate aspects of identity and purity for vitamins on the European market.
Sources: en.wikipedia.org
Austin no-showed the Raw after WrestleMania and took a week-long break without the company's consent, citing exhaustion. Austin returned on the April 1 episode of Raw, the first of the new "brand extension" era. The show was centered around which show he would sign with, and he ultimately chose Raw. Austin entered a feud with The Undertaker that resulted in a number-one contender's match for the Undisputed WWF Championship at Backlash on April 21, which Austin lost. In a May interview on WWE's internet program, Byte This!, Austin stunned the company and fans by launching a verbal attack on the direction the company was heading in and slated the creative team for not using him the way he felt they previously did. The WWE rehired Eddie Guerrero for Austin to feud with, while also prepping Austin for a feud with Brock Lesnar. However, Austin balked at the proposition that he lose a King of the Ring qualifying match on Raw to Lesnar, and ultimately walked out of the company. Austin later explained that he thought hot-shotting a rookie made Austin look weak, and airing the match on free television with no build-up did not give Lesnar a proper stage for such a big win over a star of Austin's magnitude. Further fanning the flames among Austin's growing number of detractors was a well-publicized domestic dispute incident between Austin and his wife Debra (see below). After Austin again no-showed the June 10 episode of Raw, his storylines were immediately dropped.
A contradiction of this theory is that syndicates had developed long before large-scale Sicilian immigration in the 1860s, with these immigrants merely joining a widespread phenomenon of crime and corruption.
==== D. Lymphatic system of the nose ==== The pertinent nasal lymphatic system arises from the superficial mucosa, and drains posteriorly to the retropharyngeal nodes (in back), and anteriorly (in front), either to the upper deep cervical nodes (in the neck), or to the submandibular glands (in the lower jaw), or into both the nodes and the glands of the neck and the jaw.
The following summer, 250 of A&W's restaurants began hand-breading their chicken tenders, moving towards higher-quality menu items and expanding their chicken category. In April 2014, the Hand-Breaded Chicken Tender Texas Toast Sandwich was added to the menu as a limited-time offering, along with a campaign to create the world's longest branded hashtag. In June 2014, A&W launched two new flavors of its Polar Swirl dessert treat: Sour Patch Kids and Nutter Butter.
Sources: en.wikipedia.org
No. Cardarine is a PPARδ agonist, while selective androgen receptor modulators act on androgen receptors. The two classes differ in receptor target and downstream effects.
Preclinical rodent studies reported cancers, including liver and bladder tumors, at tested doses. The human relevance of those findings is uncertain, but development was discontinued. No approved human product resulted.
No. It remains an investigational compound without approved therapeutic labeling. Sports regulators prohibit its use, and health agencies have warned against consuming it.
Anti-doping and clinical laboratories commonly use liquid chromatography-tandem mass spectrometry. The method can identify GW501516 and its metabolites in urine or blood. Detection depends on sample timing and the amount present.