Everything below concerns Anti-doping. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-11-26. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
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 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.
| 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. |
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.
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.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
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.
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.
=== Connection to depression === There is evidence for a link between inflammation and depression. Inflammatory processes can be triggered by negative cognitions or their consequences, such as stress, violence, or deprivation. Thus, negative cognitions can cause inflammation that can, in turn, lead to depression. In addition, there is increasing evidence that inflammation can cause depression because of the increase of cytokines, setting the brain into a "sickness mode". Classical symptoms of being physically sick, such as lethargy, show a large overlap in behaviors that characterize depression. Levels of cytokines tend to increase sharply during the depressive episodes of people with bipolar disorder and drop off during remission. Furthermore, it has been shown in clinical trials that anti-inflammatory medicines taken in addition to antidepressants not only significantly improves symptoms but also increases the proportion of subjects positively responding to treatment. Inflammations that lead to serious depression could be caused by common infections such as those caused by a virus, bacteria or even parasites.
== Regulation == NADK is highly regulated by the redox state of the cell. Whereas NAD is predominantly found in its oxidized state NAD+, the phosphorylated NADP is largely present in its reduced form, as NADPH. Thus, NADK can modulate responses to oxidative stress by controlling NADP synthesis. Bacterial NADK is shown to be inhibited allosterically by both NADPH and NADH. NADK is also reportedly stimulated by calcium/calmodulin binding in certain cell types, such as neutrophils. NAD kinases in plants and sea urchin eggs have also been found to bind calmodulin.
Peripheral membrane proteins, or extrinsic membrane proteins, are membrane proteins that adhere only temporarily to the biological membrane with which they are associated. These proteins attach to integral membrane proteins, or penetrate the peripheral regions of the lipid bilayer. The regulatory protein subunits of many ion channels and transmembrane receptors, for example, may be defined as peripheral membrane proteins. In contrast to integral membrane proteins, peripheral membrane proteins tend to collect in the water-soluble component, or fraction, of all the proteins extracted during a protein purification procedure. Proteins with GPI anchors are an exception to this rule and can have purification properties similar to those of integral membrane proteins. The reversible attachment of proteins to biological membranes has shown to regulate cell signaling and many other important cellular events, through a variety of mechanisms. For example, the close association between many enzymes and biological membranes may bring them into close proximity with their lipid substrate(s). Membrane binding may also promote rearrangement, dissociation, or conformational changes within many protein structural domains, resulting in an activation of their biological activity. Additionally, the positioning of many proteins are localized to either the inner or outer surfaces or leaflets of their resident membrane. This facilitates the assembly of multi-protein complexes by increasing the probability of any appropriate protein–protein interactions.
Sources: en.wikipedia.org
=== Scientific instrumentation === HVEC represented a shift in how experimental physics acquired its tools. Before the company's founding, laboratories typically built accelerators from scratch; HVEC's mass-produced instruments made reliable high-voltage machines available to institutions without in-house engineering capacity. The result was a rapid expansion of experimental nuclear physics. At the field's peak in the mid-1970s, nearly 70 percent of published papers relied on data from HVEC accelerators. Presidential science adviser D. Allan Bromley, who worked with the first HVEC tandem at Chalk River, called the machines "superb nuclear science instruments." In a 1984 assessment, he concluded that "of all the accelerators yet devised in nuclear science I believe that a very strong case can be made that the large tandems span the greatest range and scope of physics."
==== Reception ==== Patrick Anderson of the Washington Post has praised McKinty as a leading light of the "new wave" of Irish crime novelists along with Ken Bruen, Declan Hughes and John Connolly. He often uses the classic noir tropes of revenge and betrayal to explore his characters' existential quest for meaning in a bleak but lyrically intense universe. Steve Dougherty writing in The Wall Street Journal praised McKinty's use of irony and humour as a counterpoint to the violent world inhabited by McKinty's Sean Duffy character. Liam McIlvanney, writing in the Irish Times, singled out McKinty's lyrical prose style as the defining characteristic of the Duffy series. Some reviewers have criticised the explicit use of violence in his novels. However, in reviewing McKinty's Fifty Grand in The Guardian, John O'Connor called him a "master craftsman of violence and redemption, up there with the likes of Dennis Lehane." His novel The Dead Yard was selected by Publishers Weekly as one of the 12 Best Novels of 2006. Audible selected Falling Glass as the Best Mystery or Thriller of 2011. In the Morning I'll Be Gone was named as one of the 10 best crime novels of 2014 by the American Library Association. In 2016, The Guardian included book 5 of the Sean Duffy series, Rain Dogs, about the investigation of a death at Carrickfergus Castle, in their "The best recent thrillers" coverage.
=== Grain-free and low-carbohydrate === Some dog food products differentiate themselves as grain- or carbohydrate-free to offer the consumer an alternative, claiming carbohydrates in pet foods to be fillers with little or no nutritional value. A study published in Nature suggests that domestic dogs' ability to easily metabolize carbohydrates may be a key difference between wolves and dogs. Some consumers and manufacturers say dogs perform better on grain-free diets, while some veterinarians doubt this for a lack of scientific evidence. In 2019, a study comparing dry dog food that was manufactured in the United States found that 75% of food containing feed grade grains also contained measurable levels of various mycotoxins (discussed below), while none of the grain-free dry diets tested had any detectable levels of mycotoxins. Feed grade (lower quality grade) grains that are allowed to spoil and become moldy are the suspected source of the mycotoxins. This is the first published study to show a potential health benefit to feeding grain-free commercial dry pet foods. In 2019, the U.S. Food and Drug Administration identified 16 dog food brands linked to canine heart disease. The FDA has investigated more than 500 cases of dilated cardiomyopathy (DCM) in dogs eating food marketed as grain-free. The 16 brands are: Acana, Zignature, Taste of the Wild, 4Health, Earthborn Holistic, Blue Buffalo, Nature's Domain, Fromm, Merrick, California Natural, Natural Balance, Orijen, Nature's Variety, NutriSource, Nutro, and Rachael Ray Nutrish.
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.
Anti-doping laboratories typically use LC-MS/MS to detect GW501516 and its metabolites in urine. The method is sensitive and can identify the compound at low concentrations. Detection depends on sample timing, metabolism, and the specific assay.