If you have been reading about PPARδ agonist and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2025-08-09. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
The pharmacological interest in cardarine centers on PPARδ activation and its downstream effects on lipid handling and mitochondrial function. In animal studies, PPARδ agonists have been associated with changes in exercise endurance and fatty acid utilization, though results vary by model and protocol. Human data remain sparse, and the absence of large controlled trials limits conclusions about efficacy. Researchers often describe the compound as a tool for probing PPARδ biology rather than a proven therapeutic agent.
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
| 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. |
Cardarine is the common name for GW501516, a synthetic compound studied as a peroxisome proliferator-activated receptor delta agonist. Researchers developed it to explore treatments for lipid disorders and metabolic conditions. It is not an approved medicine in any country. Early clinical work examined changes in HDL cholesterol and triglycerides, but development was discontinued after animal studies raised concerns about cancer. The compound remains available as a research chemical and appears in discussions of performance enhancement.
At the molecular level, GW501516 binds and activates PPARδ, a nuclear receptor that regulates transcription. Activation shifts expression of genes involved in fatty acid oxidation, energy expenditure, and lipid transport in skeletal muscle and liver. Animal studies report increased endurance and altered lipid profiles after exposure. Human data are limited to small trials and do not establish long-term safety or efficacy. PPARδ also has roles in cell proliferation, so the relationship between activation and cancer risk remains an open question.
Published literature on cardarine includes in vitro assays, rodent experiments, and a small number of human studies. Reports describe effects on exercise capacity and lipid metabolism in animals, while human evidence is sparse. Many online descriptions present the compound as a proven endurance aid, a claim not supported by regulatory approval or large clinical trials. Analytical studies focus on identifying the parent compound and its metabolites in biological samples. Important uncertainties include species differences, dose-response relationships, and the relevance of rodent tumor findings to humans.
Sporting authorities added GW501516 to prohibited lists after it appeared in athlete samples and online markets. The World Anti-Doping Agency classifies it as a hormone and metabolic modulator, and its use can lead to an anti-doping rule violation. Some early laboratory work suggested effects on fatty acid oxidation and endurance-related metabolism in animals, but those findings do not establish safe or effective use in people. Reports of adverse events in humans are scarce and often anecdotal, which complicates risk assessment.
Legal status varies by country. In some places, cardarine is controlled under medicines or psychoactive substances laws; in others, it may be sold with minimal oversight as a research chemical. Customs agencies have intercepted shipments, and several national health agencies have issued warnings about products marketed for bodybuilding or performance enhancement. The lack of a standardized pharmaceutical supply means identity, purity, and contamination levels can differ widely between samples. These factors make cardarine a regulatory and public health concern rather than a conventional prescription drug.
Cardarine is a common name for GW501516, a synthetic compound first described in the 1990s as a selective agonist of the peroxisome proliferator-activated receptor delta. It was studied in preclinical models for metabolic and cardiovascular conditions, but it has not been approved as a medicine in the United States, Europe, or other major jurisdictions. Retail products labeled as cardarine are generally research chemicals or supplements, not pharmaceutical formulations. Because human safety and efficacy data remain limited, regulatory agencies treat it as an unapproved substance rather than a therapeutic product.
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.
== Clinical significance relevance == The protein UBC9 encoded by the UBE2I gene has been shown to be targeted by multiple viruses, including HIV and HPV. It has been hypothesized that these viruses hijack UBC9 to serve their own purposes.
=== Initial 90-day freeze === On January 24, 2025, President Donald Trump ordered a near-total freeze on all foreign aid. In February, the administration placed most employees on administrative leave. The absence of authorization from Congress led to lawsuits against the Trump administration. Also in February, the administration made several allegations of wasteful spending and fraud, allegations which were generally reported to be false. Several days later, Secretary of State Marco Rubio issued a waiver for humanitarian aid. However, a key issue developed over whether the waivers for lifesaving aid were actually translating into aid flowing. Despite the waiver, there was still much confusion about what agencies should do. More than 1,000 USAID employees and contractors were fired or furloughed following the near-total freeze on U.S. global assistance that the second Trump administration implemented. On January 27, 2025, the agency's official government website was shut down.
Analysis of Proteins Using Immunoprecipitation at ufl.edu Immunoprecipitation at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Chromatin+immunoprecipitation at the U.S. National Library of Medicine Medical Subject Headings (MeSH) Introduction to Immunoprecipitation Methodology Co-Immunoprecipitation (Co-IP) Technical
Liquid–liquid extraction is a method to separate compounds based on their relative solubilities in two different immiscible liquids, often water and an appropriate organic solvent. During extraction process, there is a net transfer of one or more components between the two liquid phases. This partitioning of compounds allows for purification of reaction mixtures or transfer of desirable products to an organic phase that is more easily evaporated than water. Liquid–liquid extraction is a technique used in both chemical laboratories and in industrial separations. Separatory funnels are commonly used for small-scale separations in research or teaching labs. Liquid-liquid extraction is commonly used for organic compounds in the scent/flavor industry, the pharmaceutical industry, and other chemical industries. Metal ions can also be separated using appropriate chelating agents to favor extraction of certain ions into aqueous vs. organic phases like the PUREX process used to separate uranium from plutonium. Liquid-Liquid extraction can be substantially accelerated in microfluidic devices, reducing extraction and separation times from minutes/hours to mere seconds compared to conventional extractors.
Sources: en.wikipedia.org
== Interactions == There have been reports of increased liver toxicity in people with HIV/AIDS on zidovudine or efavirenz when treated with amodiaquine-containing ACT regimens, therefore it is recommended that these people avoid amodiaquine.
Fluorescent proteins with other chromophores, such as UnaG with bilirubin, can display unique properties like red-shifted emission above 600 nm or photoconversion from a green-emitting state to a red-emitting state. They can have excitation and emission wavelengths far enough apart to achieve conversion between red and green light. A new class of fluorescent protein was engineered from α-allophycocyanin, a phycobiliprotein found in the cyanobacterium Trichodesmium erythraeum, and was named small ultra red fluorescent protein (smURFP) in 2016. smURFP autocatalytically incorporates the chromophore biliverdin without the need for an external protein known as a lyase. Jellyfish- and coral-derived GFP-like proteins require oxygen and produce a stoichiometric amount of hydrogen peroxide upon chromophore formation. smURFP does not require oxygen or produce hydrogen peroxide. smURFP has a large extinction coefficient (180,000 M−1 cm−1) and has a modest quantum yield (0.20), which makes it comparable biophysical brightness to eGFP and ~2-fold brighter than most red or far-red fluorescent proteins derived from coral. smURFP spectral properties are similar to the organic dye Cy5.
Methods incorporating chromatography generally begin with cryodepleted plasma undergoing buffer exchange via either diafiltration or buffer exchange chromatography, to prepare the plasma for following ion exchange chromatography steps. After ion exchange there are generally further chromatographic purification steps and buffer exchange. For further information see chromatography in blood processing.
Sources: en.wikipedia.org
=== Sepsis === People in sepsis may have micronutrient deficiencies, including low levels of vitamin C. An intravenous intake of doses much higher than the RDA, such as 3 g/d or more, appears to be needed to maintain normal plasma concentrations in people with sepsis, as the body's demand for vitamin C may increase significantly due to the heightened inflammatory response and oxidative stress. Sepsis mortality may be reduced with administration of intravenous vitamin C.
== Prognosis == In open-angle glaucoma, the typical progression from normal vision to complete blindness takes about 25 years to 70 years without treatment, depending on the method of estimation used.
Despite the trial data failing to show improvements in bone density on QCT scans, its primary goal, there were improvements on DXA scans. In a September 2020 press release, Mereo said it was seeking to do a phase III trial in 2021, and had received a Rare Pediatric Disease (RPD) designation from the US Food and Drug Administration (FDA). Romosozumab, which is also a monoclonal antibody targeting sclerostin, is an approved drug in the US and EU for the treatment of osteoporosis. The pharmaceutical industry analyst Evercore has remarked that "it could wipe out setrusumab's economics", as romosozumab is priced more cheaply than a drug for a rare disease would be, claiming that it will be "vital" to Ultragenyx's profit margins to prove its setrusumab is more efficacious than romosozumab for OI. A clinical trial evaluating romosozumab's efficacy in OI began in September 2020 and as of September 2021 is ongoing. Ultragenyx predicts that its phase 2/3 trials for setrusumab will be completed in 2026.
== Structure == A triple helix is named such because it is made up of three separate helices. Each of these helices shares the same axis, but they do not take up the same space because each helix is translated angularly around the axis. Generally, the identity of a triple helix depends on the type of helices that make it up. For example: a triple helix made of three strands of collagen protein is a collagen triple helix, and a triple helix made of three strands of DNA is a DNA triple helix. As with other types of helices, triple helices have handedness: right-handed or left-handed. A right-handed helix moves around its axis in a clockwise direction from beginning to end. A left-handed helix is the right-handed helix's mirror image, and it moves around the axis in a counterclockwise direction from beginning to end. The beginning and end of a helical molecule are defined based on certain markers in the molecule that do not change easily. For example: the beginning of a helical protein is its N terminus, and the beginning of a single strand of DNA is its 5' end. The collagen triple helix is made of three collagen peptides, each of which forms its own left-handed polyproline helix. When the three chains combine, the triple helix adopts a right-handed orientation. The collagen peptide is composed of repeats of Gly-X-Y, with the second residue (X) usually being Pro and the third (Y) being hydroxyproline.
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 an investigational synthetic compound that acts as a PPARδ agonist. It is also known as GW501516 and has been studied mainly in preclinical research. It is not an approved medicine.