carcinogenicity raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-12-13 and is reviewed periodically as new material appears.
Clinical development stopped after rodent studies showed tumors at multiple sites. Whether those findings predict human cancer risk remains an open question, but they led sponsors to discontinue programs. Human safety data are limited to small, short-term studies that were not designed to assess cancer risk. Reported effects in those studies included changes in blood lipids, but the evidence is insufficient for medical use. Long-term consequences of nonmedical use are not well characterized. Questions about dose, duration, and individual susceptibility remain unresolved.
Cardarine is a common name for GW501516, an investigational compound developed in the 1990s for metabolic conditions. It acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in lipid and energy metabolism. The compound is frequently mislabeled as a selective androgen receptor modulator, or SARM, but its molecular target is different. GW501516 reached early clinical testing before development was discontinued. It has no approved therapeutic use in any country. The name cardarine is not a formal international nonproprietary name.
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 |
|---|---|---|
| Common synonyms | GW501516; GW-1516; endurobol | GW501516 is the research code |
| Drug class | PPARδ agonist | Not a selective androgen receptor modulator |
| Molecular formula | C21H18F3NO3S2 | Established chemical formula |
| Molar mass | 453.5 g/mol | Calculated from the formula |
| Regulatory status | Prohibited in sport; not approved as medicine | Status varies by country |
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.
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.
Laboratory studies indicate that GW501516 activates PPARδ, a nuclear receptor involved in fatty acid oxidation and energy metabolism. In rodent experiments, treated animals often showed increased endurance and reduced fat mass. These effects were observed under controlled conditions and do not establish safe or effective use in humans. The exact dose-response relationship in humans remains poorly characterized. Species differences in metabolism can affect how results translate across animals and people.
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.
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.
The topic of IAQ has become popular due to the greater awareness of health problems caused by mold and triggers to asthma and allergies. In the US, the Environmental Protection Agency (EPA) has developed an "IAQ Tools for Schools" program to help improve the indoor environmental conditions in educational institutions. The National Institute for Occupational Safety and Health conducts Health Hazard Evaluations (HHEs) in workplaces at the request of employees, authorized representative of employees, or employers, to determine whether any substance normally found in the place of employment has potentially toxic effects, including indoor air quality. A variety of scientists work in the field of indoor air quality, including chemists, physicists, mechanical engineers, biologists, bacteriologists, epidemiologists, and computer scientists. Some of these professionals are certified by organizations such as the American Industrial Hygiene Association, the American Indoor Air Quality Council and the Indoor Environmental Air Quality Council. In the UK, under the Department for Environment Food and Rural Affairs, the Air Quality Expert Group considers current knowledge on indoor air quality and provides advice to government and devolved administration ministers. At the international level, the International Society of Indoor Air Quality and Climate (ISIAQ), formed in 1991, organizes two major conferences, the Indoor Air and the Healthy Buildings series.
Atmospheric pressure photoionization (APPI) is a soft ionization method used in mass spectrometry (MS) usually coupled to liquid chromatography (LC). Molecules are ionized using a vacuum ultraviolet (VUV) light source operating at atmospheric pressure (105 Pa), either by direct absorption followed by electron ejection or through ionization of a dopant molecule that leads to chemical ionization of target molecules. The sample is usually a solvent spray that is vaporized by nebulization and heat. The benefit of APPI is that it ionizes molecules across a broad range of polarity and is particularly useful for ionization of low polarity molecules for which other popular ionization methods such as electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) are less suitable. It is also less prone to ion suppression and matrix effects compared to ESI and APCI and typically has a wide linear dynamic range. The application of APPI with LC/MS is commonly used for analysis of petroleum compounds, pesticides, steroids, and drug metabolites lacking polar functional groups and is being extensively deployed for ambient ionization particularly for explosives detection in security applications.
Before they can stop her, Mossman teleports herself and Eli to the Citadel. The teleporter explodes moments after Gordon and Alyx use it to escape Nova Prospekt. Returning to Kleiner's lab, Gordon and Alyx learn that the teleporter malfunctioned and that a week has passed, during which time the Resistance has used the attack on Nova Prospekt to launch an armed rebellion against the Combine. Aided by Barney and Dog, Gordon fights his way to the Citadel. Inside, a security system vaporizes his weapons but inadvertently super-charges the gravity gun; this helps Gordon climb the tower. He is captured and taken in a transport pod to Breen's private office, near the Citadel's apex, where he and Mossman are waiting with Eli and Alyx as captives. Breen reveals that he plans to use them as leverage to negotiate with the Combine, contradicting what he had told Mossman. Angered, Mossman frees the captives and Breen attempts to escape using a teleporter. Gordon destroys the reactor and Breen falls into the abyss. Moments after the reactor explodes, the G-Man reappears and freezes time, praises Gordon's actions, and returns him to stasis.
To perform a selective separation, the distribution ratio of the solute to be extracted must be greater than one, whereas that belonging to the solutes which remain in the aqueous feed must be lower than one. This always yields a separation factor SF > 1. Generally, the effects of acidity and temperature on distribution ratios and the separation factor are investigated because the main species with actinides and lanthanides could be prone to decomplexation upon increasing acidity due to protonation of the ligand or due to increasing temperature. The thermodynamic effects are usually investigated by performing extraction tests at increasing temperature. Furthermore, thermodynamics studies can assess the several alkyl chains of a ligand on its complexation properties towards minor actinides than lanthanides. The extraction processes are based on the complexation of metal ions with lipophilic or hydrophilic ligands. The extracting agent forms a coordination complex with the metal ion as a product of a Lewis acid-base reaction. Ligands are named bases (donors) and contain at least one electron lone pair to donate to metal ions named acids (acceptors). Metal cations in the aqueous feed raffinate are generally solvated by coordinating water molecules through the donor oxygen atoms to form aquo ions
Sources: en.wikipedia.org
== Scholarly works == Clinical, laboratory and imaging features of COVID-19: A systematic review and meta-analysis, Published in Travel Medicine and Infectious Disease, Volume 34, March–April 2020 Central nervous system involvement by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), Published in The Journal of Medical Virology, Volume 92 Issue 7, July 2020 Probable Zoonotic Leprosy in the Southern United States, Published in the New England Journal of Medicine, April 28, 2011. ChikDenMaZika Syndrome: the challenge of diagnosing arboviral infections in the midst of concurrent epidemics, Published in Annals of Clinical Microbiology and Antimicrobials, Article 42, July 22, 2016. Lobomycosis in Venezuela, Published in the International Journal of Dermatology, Volume 46, Issue 22, February 2007. Venezuela's humanitarian crisis, resurgence of vector-borne diseases, and implications for spillover in the region, Published in The Lancet, Volume 19, Issue 5, May 2019.
8-Hydroxyamoxapine is an active metabolite of the antidepressant drug amoxapine (Asendin). It contributes to amoxapine's pharmacology. It is a serotonin-norepinephrine reuptake inhibitor (SNRI) with similar norepinephrine, but more serotonin, reuptake inhibition as its parent compound. It plays a part in balancing amoxapine's ratio of serotonin to norepinephrine transporter blockage.
==== Complement Activation ==== The complement system includes blood proteins that can cause cell death after an antibody binds to the cell surface (the classical complement pathway, among the ways of complement activation). Generally, the system deals with foreign pathogens but can be activated with therapeutic antibodies in cancer. The system can be triggered if the antibody is chimeric, humanized, or human; as long as it contains the IgG1 Fc region. Complement can lead to cell death by activation of the membrane attack complex, known as complement-dependent cytotoxicity; enhancement of antibody-dependent cell-mediated cytotoxicity; and CR3-dependent cellular cytotoxicity. Complement-dependent cytotoxicity occurs when antibodies bind to the cancer cell surface, the C1 complex binds to these antibodies and subsequently, protein pores are formed in cancer cell membrane. Blocking Antibody therapies can also function by binding to proteins and physically blocking them from interacting with other proteins. Checkpoint inhibitors (CTLA-4, PD-1, and PD-L1) operate by this mechanism. Briefly, checkpoint inhibitors are proteins that normally help to slow immune responses and prevent the immune system from attacking normal cells. Checkpoint inhibitors bind these proteins and prevent them from functioning normally, which increases the activity of the immune system. Examples include durvalumab, ipilimumab, nivolumab, and pembrolizumab.
Sources: en.wikipedia.org
No. Cardarine is GW501516, a PPARδ agonist, while SARMs act on androgen receptors. The two classes are often grouped in informal discussions despite different mechanisms.
No. It has no approved medical indication in any country. Regulatory agencies have not cleared it for treatment or prevention of any condition.
Early clinical work stopped after rodent carcinogenicity findings. Those animal results raised concerns about long-term human risk, although direct human evidence is lacking. The human relevance of the tumors remains an open scientific question.
LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.