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Detection, Stability, And Quality — Complete Guide

By Editorial Desk · published 2025-12-12 · last reviewed 2026-01-05 · Wiki

If you have been reading about GW501516 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 2026-01-05. Numbers and descriptions here follow the published literature rather than marketing material.

Detection, Stability, and Quality

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.

Background and Regulatory Status

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.

Cardarine at a glance

PropertyValueNotes
AppearanceWhite to off-white powderCommon for reference-grade material.
SolubilityLow in waterDissolves in DMSO and some organic solvents.
Typical storage-20 °C, desiccatedProtect from light and moisture.
Analytical methodLC-MS/MSUsed for trace detection in biological matrices.
Purity assessmentHPLC with UV detectionOften combined with NMR and mass spectrometry.

Mechanism and Safety Research

GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.

Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.

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Regulation and Detection

Anti-doping laboratories identify GW501516 and related metabolites using liquid chromatography coupled with tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be analyzed. The method targets the parent compound and phase I and phase II metabolites, which extend the detection window. Because the substance is prohibited at all times, athletes can be tested outside competition. Detection limits and windows depend on the assay, sample type, and individual metabolism.

Cardarine is frequently described as a fat-burning or endurance-enhancing supplement, but these claims exceed the available evidence. The compound is not a hormone, steroid, or selective androgen receptor modulator. Research articles discuss it as a tool compound for studying PPARδ biology, while anti-doping literature focuses on its abuse and detection. Quality of unapproved products is uncertain, and independent analyses have found impurities or incorrect labeling. Open questions include whether human cancer risk resembles that seen in rodents and how often non-athletes use the substance.

Cardarine has no approved therapeutic indication and is not marketed as a medicine. The World Anti-Doping Agency lists GW501516 as a prohibited substance at all times, covering both in-competition and out-of-competition periods. National laws vary: some countries treat it as an unapproved drug subject to import controls, while others have specific restrictions on sale for human consumption. It is often sold as a research chemical, a label that does not imply safety or legality. Enforcement actions have targeted online vendors and shipments.

Identity and Regulatory Status

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.

Regulatory treatment varies, but cardarine is not approved as a medicine. Sports authorities list GW501516 as a prohibited substance, and it is banned at all times under the World Anti-Doping Agency code. Many countries restrict sales for human consumption, while online vendors market it as a research chemical. Such products may lack purity data, and their actual contents can differ from the label. Purchasing or possessing cardarine may carry legal consequences depending on jurisdiction. The compound is not a dietary supplement ingredient in regulated markets.

Reference notes

=== 4 September === One person was killed in an SAF drone strike on a market in Manawashi, South Darfur. The drone responsible was shot down by the RSF over Mershing, with RSF commanders claiming that it was a Baykar Bayraktar Akıncı drone.

Although increases in immunoglobulins usually increase the ESR, very high levels can reduce it again due to hyperviscosity of the plasma. This is especially likely with IgM-class paraproteins, and to a lesser extent, IgA-class. The basal ESR is slightly higher in females.

require that the partial double bond be broken, so that the activation energy is roughly 80 kJ/mol (20 kcal/mol). However, the activation energy can be lowered (and the isomerization catalyzed) by changes that favor the single-bonded form, such as placing the peptide group in a hydrophobic environment or donating a hydrogen bond to the nitrogen atom of an X-Pro peptide group. Both of these mechanisms for lowering the activation energy have been observed in peptidyl prolyl isomerases (PPIases), which are naturally occurring enzymes that catalyze the cis-trans isomerization of X-Pro peptide bonds. Conformational protein folding is usually much faster (typically 10–100 ms) than cis-trans isomerization (10–100 s). A nonnative isomer of some peptide groups can disrupt the conformational folding significantly, either slowing it or preventing it from even occurring until the native isomer is reached. However, not all peptide groups have the same effect on folding; nonnative isomers of other peptide groups may not affect folding at all.

=== Thermal-induced phase separation === Thermal-induced phase separation separates a homogenous polymer solution into a multi-phase system via thermodynamic changes. The procedure involves five steps: polymer dissolution, liquid-liquid or liquid-solid phase separation, polymer gelation, extraction of solvent from the gel with water, and freezing and freeze-drying under vacuum. Thermal-induced phase separation method is widely used to generate scaffolds for tissue regeneration. The homogenous polymer solution in the first step is thermodynamically unstable and tends to separate into polymer-rich and polymer-lean phases under appropriate temperature. Eventually after solvent removal, the polymer-rich phase solidifies to form the matrix and the polymer-lean phase develops into pores. Next, two types of phase separation can be carried out on the polymer solution depending on the desired pattern. Liquid-liquid separation is usually used to form bicontinuous phase structures while solid-liquid phase separation is used to form crystal structures. The gelation step plays a crucial role in controlling the porous morphology of the nanofibrous matrices. Gelation is influenced by temperature, polymer concentration, and solvent properties. Temperature regulates the structure of the fiber network: low gelation temperature results in formation of nanoscale fiber networks while high gelation temperature leads to the formation of a platelet-like structure.

Sources: en.wikipedia.org

Notes from published material

The first application of 238Pu was its use in nuclear weapon components made at Mound Laboratories for Lawrence Radiation Laboratory (now Lawrence Livermore National Laboratory). Mound was chosen for this work because of its experience in producing the polonium-210-fueled Urchin initiator and its work with several heavy elements in a Reactor Fuels program. Two Mound scientists spent 1959 at Lawrence in joint development while the Special Metallurgical Building was constructed at Mound to house the project. Meanwhile, the first sample of 238Pu came to Mound in 1959. The Milliwatt Radioisotopic Thermoelectric Generator is used to provide power to Permissive Action Links (PAL) in US nuclear weapons.

The primary purpose of freeze drying within the food industry is to extend the shelf-life of the food while maintaining the quality. Freeze-drying is known to result in the highest quality of solid foods of all drying techniques because structural integrity is maintained along with preservation of flavors. Because freeze drying is expensive, it is used mainly with high-value products. Examples of high-value freeze-dried products are seasonal fruits and vegetables because of their limited availability, and foods used for military rations, astronauts/cosmonauts, and/or hikers. Water-based drinks such as coffee and tea are also freeze-dried. Compared to heat-based drying, freeze-drying preserves more volatile aroma compounds. Freeze-drying is also used to make instant soup bricks. It can also preserve raw ingredients such as egg whites for baking.

Casamino acid is the mixture of amino acids produced from acid hydrolysis of casein, a family of phosphoproteins found in mammalian milk. In comparison, tryptone describes casein that has undergone enzymatic degradation by the protease trypsin, leaving many smaller peptide chains alongside the free amino acids. Casamino acid is used as a component of microbiological growth medium to support protein synthesis. However, tryptophan, an essential amino acid, is lost while digesting the casein with strong acids. Providing this abundant source of nitrogen can alter the phenotype of microorganisms, such as bacterial species recognizing nutrient-rich media and reducing their motility, as compared to their typical environmental behaviors.

Sources: en.wikipedia.org

Frequently asked questions

How is cardarine measured in biological samples?

LC-MS/MS is common, often after sample cleanup. The assay targets GW501516 or its metabolites.

What storage conditions are typical for reference material?

Reference material is usually kept cold, dry, and protected from light. Frozen aliquots reduce repeated freeze-thaw cycles.

Why can purity vary between products?

No approved pharmaceutical product exists, so manufacturing and quality controls are not standardized. Products may contain different compounds or impurities.

Is cardarine approved for human use?

No. Major drug regulators have not approved GW501516 for treating any medical condition. Products sold as cardarine are typically unapproved research chemicals or supplements, so their contents and safety are not assured.

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