Nuclear receptor 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 2026-03-04 and is reviewed periodically as new material appears.
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.
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.
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.
| 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. |
Cardarine is a synthetic compound also known as GW501516, GW-501516, and sometimes endurobol. It was developed as a selective agonist of peroxisome proliferator-activated receptor delta, a nuclear receptor involved in fatty acid oxidation and energy metabolism. The compound was studied in preclinical models for metabolic and cardiovascular conditions, but it did not become a marketed human medicine. In regulatory and anti-doping contexts, it is treated as a prohibited substance rather than a licensed medicine.
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.
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.
=== As an antibiotic target === The sortases are thought to be good targets for new antibiotics as they are important proteins for pathogenic bacteria and some limited commercial interest has been noted by at least one company.
Single display resolutions One 16K (15360 × 8640) display @ 60 Hz with 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (with DSC) One 10K (10240 × 4320) display @ 60 Hz and 8 bpc (24 bit/px, SDR) RGB/Y′CBCR 4:4:4 color (uncompressed) Dual display resolutions Two 8K (7680 × 4320) displays @ 120 Hz and 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (with DSC) Two 4K (3840 × 2160) displays @ 144 Hz and 8 bpc (24 bit/px, SDR) RGB/Y′CBCR 4:4:4 color (uncompressed) Triple display resolutions Three 10K (10240 × 4320) displays @ 60 Hz and 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (with DSC) Three 4K (3840 × 2160) displays @ 90 Hz and 10 bpc (30 bit/px, HDR) RGB/Y′CBCR 4:4:4 color (uncompressed) When using only two lanes on the USB-C connector via DP Alt Mode to allow for simultaneous SuperSpeed USB data and video, DP 2.0 can enable such configurations as:
Today, roughly one third of the city's residents are employed by the government, and tourism is also a major source of employment. On days when two or more large cruise ships dock in the town, tourists frequently outnumber the local residents. Peat was once a prominent heating/fuel source in Stanley, and stacks of drying peat under cover can still be seen by the occasional house.
Sources: en.wikipedia.org
== Synthesis == Neuropeptides are synthesized from inactive precursor proteins called prepropeptides. Prepropeptides contain sequences for a family of distinct peptides and often contain duplicated copies of the same peptides, depending on the organism. In addition to the precursor peptide sequences, prepropeptides also contain a signal peptide, spacer peptides, and cleavage sites. The signal peptide sequence guides the protein to the secretory pathway, starting at the endoplasmic reticulum. The signal peptide sequence is removed in the endoplasmic reticulum, yielding a propeptide. The propeptide travels to the Golgi apparatus where it is proteolytically cleaved and processed into multiple peptides. Peptides are packaged into dense core vesicles, where further cleaving and processing, such as C-terminal amidation, can occur. Dense core vesicles are transported throughout the neuron and can release peptides at the synaptic cleft, cell body, and along the axon. A single animal may use hundreds of different neuropeptides. In C. elegans, for example, 120 genes specify more than 250 neuropeptides.
==== Evolution of animal synthesis ==== Ascorbic acid is a common enzymatic cofactor in mammals used in the synthesis of collagen, as well as a powerful reducing agent capable of rapidly scavenging a number of reactive oxygen species (ROS). Given that ascorbate has these important functions, it is surprising that the ability to synthesize this molecule has not always been conserved. In fact, anthropoid primates, Cavia porcellus (guinea pigs), teleost fishes, most bats, and some passerine birds have all independently lost the ability to internally synthesize vitamin C in either the kidney or the liver. In all of the cases where genomic analysis was done on an ascorbic acid auxotroph, the origin of the change was found to be a result of loss-of-function mutations in the gene that encodes L-gulono-γ-lactone oxidase, the enzyme that catalyzes the last step of the ascorbic acid pathway outlined above. One explanation for the repeated loss of the ability to synthesize vitamin C is that it was the result of genetic drift; assuming that the diet was rich in vitamin C, natural selection would not act to preserve it.
Disulfiram inhibits the enzyme acetaldehyde dehydrogenase, which in turn results in buildup of acetaldehyde, a toxic metabolite of ethanol with unpleasant effects. The medication or drug is commonly used to treat alcohol use disorder, and results in immediate hangover-like symptoms upon consumption of alcohol, this effect is widely known as disulfiram effect.
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 and clinical laboratories commonly use liquid chromatography-tandem mass spectrometry. The method can identify GW501516 and its metabolites in urine or blood. Detection depends on sample timing and the amount present.