en · de · es · fr · pt
cardarine-notes.peptides6908.com › Info › Background And Regulatory History — Hands-On Walkthrough

Background And Regulatory History — Hands-On Walkthrough

By Editorial Desk · published 2026-07-10 · last reviewed 2026-07-26 · Info

A practical reference on Research chemical: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.

This page was last updated on 2026-07-26 and is reviewed periodically as new material appears.

Background and Regulatory History

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.

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.

Mechanism and Detection Methods

GW501516 acts as a selective agonist at PPARδ, a nuclear receptor that regulates transcription of genes involved in lipid handling and energy metabolism. Activation of PPARδ in preclinical models increases fatty acid oxidation, mitochondrial biogenesis, and exercise endurance in rodents. These effects have made the compound a subject of metabolic research and also a target for sport anti-doping rules. In humans, however, controlled studies are limited, and whether similar endurance or metabolic changes occur at tolerated exposures remains an open question. The receptor’s broad tissue distribution also means downstream effects may vary by organ and condition.

Detection of GW501516 in biological samples generally relies on liquid chromatography coupled with tandem mass spectrometry. Urine is a common matrix in anti-doping analysis, while blood or plasma may be used in research settings. Sample preparation can involve enzymatic hydrolysis, protein precipitation, or solid-phase extraction before instrumental analysis. Because the compound undergoes metabolism, assays may target the parent molecule, one or more metabolites, or both. Detection windows are not fixed; they depend on factors such as dose, route, individual metabolism, and assay sensitivity. Reference standards are required for accurate identification and quantification.

Handling and quality assessment of cardarine reference material follow general laboratory practices for poorly characterized compounds. It typically appears as a white to off-white powder and is sparingly soluble in water but soluble in organic solvents such as dimethyl sulfoxide and ethanol. Storage recommendations usually specify a cool, dry, dark place, with long-term storage at low temperature and desiccation. Purity may be checked by high-performance liquid chromatography with ultraviolet detection, while identity is confirmed by mass spectrometry and nuclear magnetic resonance. No pharmacopeial monograph exists, so reported purity and stability depend on the supplier’s methods.

Cardarine at a glance

PropertyValueNotes
Common nameCardarineCommon internet and media name.
Research codeGW501516Also written GW-1516.
Drug classPPARδ agonistNot a selective androgen receptor modulator.
Development statusDiscontinuedClinical development halted after rodent cancer findings.
Regulatory statusProhibited in sportListed by WADA; not approved as medicine.

Regulation and Detection

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.

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.

Related pages on this site

Background and Research Context

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.

Regulation and Analytical Detection

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.

Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.

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.

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.

Reference notes

Ghosh SK, Paik WK, Kim S (1988). "Purification and molecular identification of two protein methylases I from calf brain. Myelin basic protein- and histone-specific enzyme". J. Biol. Chem. 263 (35): 19024–33. doi:10.1016/S0021-9258(18)37384-8. PMID 2461933.

desiccant Also drying agent. A hygroscopic substance used to induce or sustain a state of dryness or desiccation (i.e. the absence of moisture) in its vicinity by abstracting water molecules from other substances. Desiccants come in many different forms and work by many different principles, ranging from simple absorption to the chemical bonding of water molecules.

China provided a transcript of a 26 April press conference, indicating that an invitation to FDA investigators had been sent on 23 April but making no mention of banning melamine usage. On 3 May 2007, Chinese authorities detained Mao Lijun, general manager of the Xuzhou Anying Biologic Technology Development, one of the companies accused of exporting contaminated protein, on unspecified charges. On 29 May 2007, in actions not linked directly to the protein export scandal, Zheng Xiaoyu (郑筱萸), the former head of China's State Food and Drug Administration (SFDA), had been convicted of personally approving unproven and unsafe medicines after taking bribes from eight pharmaceutical companies totaling more than 6.49 million RMB (approximately 850,000 US dollars). These fraudulent approvals were estimated to have resulted in hundreds of patient deaths; consequently, Zheng was sentenced to death. It was also discovered during his eight years as head of the SFDA, Zheng had personally ordered the approval of more than 150,000 new medicines; by contrast, the U.S. FDA approves approximately 140 new medications per year. Most of those 150,000 medicines were manufactured by the eight pharmaceutical companies that bribed Zheng; one such unsafe medication, produced by the now-defunct Anhui Hua Yuan (华源) Company, resulted in 14 patient deaths and hundreds becoming permanently disabled. Zheng's former deputy was also convicted as an accomplice and given a two-year delayed death sentence.

Sources: en.wikipedia.org

Notes from published material

Soon arose the notion of a tranquilizer which was quite different from any sedative or stimulant. The term tranquilizer took over the notions of sedatives and became the dominant term in the West through the 1980s. In Japan, during this time, the term tranquilizer produced the notion of a psyche-stabilizer and the term mood stabilizer vanished. Premarin (conjugated estrogens, introduced in 1942) and Prempro (a combination estrogen-progestin pill, introduced in 1995) dominated hormone replacement therapy (HRT) regimens during the 1990s. Though not designed to cure any disease, HRT is prescribed to improve quality of life and as a preventative measure, such as treating post-menopausal symptoms. In the 1960s and early 1970s, more physicians began to prescribe estrogen for their female patients. Between 1991 and 1999, Premarin was listed as the most popular prescription and best-selling drug in America. The first oral contraceptive, Enovid, was approved by FDA in 1960. Oral contraceptives inhibit ovulation and so prevent conception. Enovid was known to be much more effective than alternatives including the condom and the diaphragm. As early as 1960, oral contraceptives were available in several different strengths by every manufacturer. In the 1980s and 1990s, an increasing number of options arose including, most recently, a new delivery system for the oral contraceptive via a transdermal patch. In 1982, a new version of "the pill" was introduced, known as the biphasic pill. By 1985, a new triphasic pill was approved.

=== Limitations === Moreover, because the assembly of the full-length gene product relies on the efficient and specific alignment of long single stranded oligonucleotides, critical parameters for synthesis success include extended sequence regions comprising secondary structures caused by inverted repeats, extraordinary high or low GC-content, or repetitive structures. Usually these segments of a particular gene can only be synthesized by splitting the procedure into several consecutive steps and a final assembly of shorter sub-sequences, which in turn leads to a significant increase in time and labor needed for its production. The result of a gene synthesis experiment depends strongly on the quality of the oligonucleotides used. For these annealing based gene synthesis protocols, the quality of the product is directly and exponentially dependent on the correctness of the employed oligonucleotides. Alternatively, after performing gene synthesis with oligos of lower quality, more effort must be made in downstream quality assurance during clone analysis, which is usually done by time-consuming standard cloning and sequencing procedures. Another problem associated with all current gene synthesis methods is the high frequency of sequence errors because of the usage of chemically synthesized oligonucleotides. The error frequency increases with longer oligonucleotides, and as a consequence the percentage of correct product decreases dramatically as more oligonucleotides are used. The mutation problem could be solved by shorter oligonucleotides used to assemble the gene.

Groups such as the Bat Conservation International aim to increase awareness of bats' ecological roles and the environmental threats they face. This group called for Bat Appreciation Week from 24–31 October every year to promote awareness of the ecological importance of bats. In the United Kingdom, all bats are protected under the Wildlife and Countryside Acts, and disturbing a bat or its roost can be punished with a heavy fine. In Sarawak, Malaysia, "all bats" are protected under the Wildlife Protection Ordinance 1998, but species such as the hairless bat (Cheiromeles torquatus) are still eaten by the local communities. Humans have caused the extinction of several species of bat in modern history, the most recent being the Christmas Island pipistrelle (Pipistrellus murrayi), which was declared extinct in 2009. Many people put up bat houses to attract bats. The 1991 University of Florida bat house is the largest occupied artificial roost in the world, with around 450,000–500,000 residents. In Britain, thick-walled and partly underground World War II pillboxes have been converted to make roosts for bats, and purpose-built 'bat bridges' are occasionally built to mitigate damage to habitat from roads or other developments. Cave gates are sometimes installed to limit human entry into caves with sensitive or endangered bat species. The gates are designed not to limit the airflow and thus to maintain the cave's micro-ecosystem. In the United States, 35 of the 47 bat species roost on human-made structures, while 14 of them use bat houses.

Sources: en.wikipedia.org

Frequently asked questions

Is cardarine a selective androgen receptor modulator?

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.

Why did clinical development stop?

Preclinical rodent studies reported cancers, including liver and bladder tumors, at tested doses. The human relevance of those findings is uncertain, but development was discontinued. No approved human product resulted.

Is cardarine approved for medical use?

No. It remains an investigational compound without approved therapeutic labeling. Sports regulators prohibit its use, and health agencies have warned against consuming it.

What receptor does cardarine target?

Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.

Network