A practical reference on Preclinical research: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-07-20. Anything still debated is marked as such rather than presented as settled.
Cardarine is a common name for GW501516, a synthetic compound developed in the 1990s through research collaborations involving GlaxoSmithKline. It belongs to a class of molecules known as peroxisome proliferator-activated receptor delta agonists. Early studies explored its effects on lipid metabolism and energy expenditure in animal models. The compound was never approved as a human medicine, and clinical development was discontinued. In the years since, it has appeared in fitness and bodybuilding communities as a performance-enhancing substance. Regulatory agencies classify it as an unapproved drug.
PPARδ is a nuclear receptor that regulates gene expression related to fatty acid oxidation, glucose homeostasis, and mitochondrial function. GW501516 binds to this receptor with high affinity and activates downstream signaling in skeletal muscle and other tissues. Animal studies reported increased endurance and altered fuel preference, but human data remain limited and inconsistent. The precise relationship between receptor activation and observed physiological changes is still an area of active investigation. Researchers have also examined whether the compound affects inflammation or cell proliferation. No approved therapeutic indication exists for cardarine.
In laboratory settings, cardarine is studied as a tool compound for probing PPARδ biology. Published experiments often use cell cultures, rodent models, or isolated tissues. Some investigations focus on metabolic effects, while others assess potential risks such as carcinogenicity observed in long-term animal studies. Because human trials are sparse, most knowledge comes from preclinical work and adverse event reports. Scientific literature frequently notes the gap between animal findings and human outcomes. The compound is not a dietary supplement and is not intended for human consumption.
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.
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.
| Property | Value | Notes |
|---|---|---|
| CAS Registry Number | 317318-70-0 | Unique identifier for the compound. |
| Chemical class | PPARδ agonist | Synthetic ligand for peroxisome proliferator-activated receptor delta. |
| Appearance | White to off-white solid | Typical form of research-grade material. |
| Solubility | Soluble in DMSO and ethanol | Poorly soluble in water. |
| Typical storage | -20°C | Recommended for long-term storage of stock solutions. |
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.
Published human data are sparse and mostly come from early-phase trials. Those studies examined short-term changes in lipids, glucose, and exercise capacity, but they were not large enough to establish efficacy or long-term safety. Some animal experiments reported increased running endurance, yet such findings do not prove a performance benefit in people. Anti-doping laboratories detect GW501516 and its metabolites in urine or blood using liquid chromatography-tandem mass spectrometry. Detection windows depend on dose, sample type, and individual metabolism. The method is sensitive enough to identify trace residues in tested samples.
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.
DCC (acronym for N,N'-dicyclohexylcarbodiimide) was one of the first carbodiimides developed as a reagent. It is widely used for amide and ester formation, especially for solid-phase synthesis of peptides. DCC has achieved popularity mainly because of its high-yielding amide coupling reactions and the fact that it is quite inexpensive. However, DCC does have some serious drawbacks, and its use is often avoided for several reasons:
Ethanol is only one of several types of chemical alcohols, and has a variety of analogues. Most other alcohols are considered poisonous. In general, higher alcohols are less toxic. Alcoholic beverages are sometimes laced with toxic alcohols. The toxicity of isopropyl alcohol is about twice that of ethanol; a mild, brief exposure to isopropyl alcohol is unlikely to cause any serious harm, although ingesting significant quantities can lead to vomiting, abdominal pain, and internal bleeding. Methanol is the most toxic alcohol. Ingestion of as little as 3.16 grams of methanol can cause irreversible optic nerve damage, and the oral LD50 for humans is estimated to be 56.2 grams. Many methanol poisoning incidents have occurred through history. n-Butanol is reported to produce similar effects to those of ethanol and relatively low toxicity (one-sixth of that of ethanol in one rat study). However, its vapors can produce eye irritation, and inhalation can cause pulmonary edema. Acetone (propanone) is a ketone rather than an alcohol, and is reported to produce similar toxic effects; it can be extremely damaging to the cornea. Although ethanol is the most prevalent alcohol in alcoholic beverages, alcoholic beverages contain several types of psychoactive alcohols, that are categorized as primary, secondary, or tertiary. Primary and secondary alcohols, are oxidized to aldehydes, and ketones, respectively, while tertiary alcohols are generally resistant to oxidation. The Lucas test differentiates between primary, secondary, and tertiary alcohols.
=== Non-TB conditions === Tentative evidence exists for a beneficial non-specific effect of intradermal BCG vaccination on overall mortality in low-income countries, or for its reducing other health problems including sepsis and respiratory infections when given early, with greater benefit the earlier it is used. There is also tentative evidence of intravesical (injected into the bladder) BCG providing some protection against future dementia.
These lacteals drain into the thoracic duct which empties into the venous blood at the junction of the left jugular and left subclavian veins on the lower left hand side of the neck. This means that the fat-soluble products of digestion are discharged directly into the general circulation, without first passing through the liver, unlike all other digestion products. The reason for this peculiarity is unknown.
Sources: en.wikipedia.org
=== Deubiquitination === Several deubiquitinating enzymes (DUBs) modulate p53 stability by removing ubiquitin chains. USP7, also known as HAUSP, can deubiquitinate both p53 and MDM2. In unstressed cells, HAUSP preferentially stabilizes MDM2, and its depletion may paradoxically increase p53 levels. USP42 is another DUB that stabilizes p53 and enhances its ability to respond to stress. USP10 operates primarily in the cytoplasm, where it counteracts MDM2 by directly deubiquitinating p53. After DNA damage, USP10 translocates to the nucleus and further stabilizes p53. It does not interact with MDM2.
=== ECG findings === With mild to moderate hyperkalemia, there may be prolongation of the PR interval and development of peaked T waves. The measurement properties (sensitivity and specificity) of ECG to predict laboratory hyperkalemia, or to predict more severe arrhythmia in the context of hyperkalemia, are not known. Severe hyperkalemia results in a widening of the QRS complex, and the ECG complex can evolve to a sinusoidal shape. There appears to be a direct effect of elevated potassium on some of the potassium channels that increases their activity and speeds membrane repolarisation. Also, (as noted above), hyperkalemia causes an overall membrane depolarization that inactivates many sodium channels. The faster repolarisation of the cardiac action potential causes the tenting of the T waves, and the inactivation of sodium channels causes a sluggish conduction of the electrical wave around the heart, which leads to smaller P waves and widening of the QRS complex. Some of the potassium currents are sensitive to extracellular potassium levels, for reasons that are not well understood. As the extracellular potassium levels increase, potassium conductance is increased so that more potassium leaves the myocyte in any given period. To summarize, classic ECG changes associated with hyperkalemia are seen in the following progression: peaked T wave, shortened QT interval, lengthened PR interval, increased QRS duration, and eventually absence of the P wave with the QRS complex becoming a sine wave.
==== Calcium and phospholipids ==== Calcium and phospholipids (constituents of platelet membrane) are required for the tenase and prothrombinase complexes to function. Calcium mediates the binding of the complexes via the terminal gamma-carboxy residues on Factor Xa and Factor IXa to the phospholipid surfaces expressed by platelets, as well as procoagulant microparticles or microvesicles shed from them. Calcium is also required at other points in the coagulation cascade. Calcium ions play a major role in the regulation of coagulation cascade that is paramount in the maintenance of hemostasis. Other than platelet activation, calcium ions are responsible for complete activation of several coagulation factors, including coagulation Factor XIII.
== Microbiology == The environment of the gingival sulcus is unlike any other location within the mouth. The ecosystem of the gingival sulcus is more anaerobic, and the site is filled with Gingival Crevicular Fluid (GCF). In the presence of periodontal disease, the gingival sulcus becomes a periodontal pocket and the oxidation reduction potential will decrease to low levels as the site is very anaerobic. At the same time, the gingival crevicular fluid would have increased by 147% when gingivitis is present and would have increased by up to 30-fold where periodontitis is present. While gingival crevicular fluid provides for the cellular defence and humoral factors to combat against the microbial insult, the gingival crevicular fluid also deliver novel substrates, in the form of proteins and glycoproteins, for bacterial metabolism. These include haeme containing molecules and iron, such as haemoglobin and transferrin. Dissimilarly to dental caries, many bacteria associated to periodontal disease cannot metabolise carbohydrates for energy (they are asaccharolytic) and are proteolytic too. One effect of proteolysis is that the pH of the gingival pocket with periodontal disease will increase and becomes slightly alkaline at around a pH level of 7.4 – 7.8 as compared to relatively neutral pH values, around a pH level of 6.9, when the gingival is healthy. In alkaline growth conditions, the enzyme activity and growth activity of periodontal pathogens, like Porphyromonas gingivalis.
Positron emission tomography imaging studies have reportedly found that tramadol levels are at least four-fold higher in the brain than in plasma. Conversely, brain levels of desmetramadol "only slowly approach those in plasma". The plasma protein binding of tramadol is only 4–20%; hence, almost all tramadol in circulation is free, thus bioactive.
Sources: en.wikipedia.org
Cardarine is a common name for GW501516, a synthetic PPARδ agonist developed for research. It has not been approved as a medication in any country. It is classified as an unapproved drug and a prohibited substance in sport.
No. Cardarine is not an anabolic steroid; it belongs to a different chemical class that targets PPARδ. Steroids act primarily through androgen receptors, while cardarine acts through a nuclear receptor involved in metabolism.
Some rodent studies reported increased endurance and changes in fat metabolism after cardarine exposure. Long-term studies in animals also raised concerns about cancer in certain tissues. Human trial data are limited, so these findings cannot be directly translated to people.
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.