Investigational drug comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Updated 2026-03-08. Numbers and descriptions here follow the published literature rather than marketing material.
Cardarine is not approved for human therapeutic use in any major jurisdiction. It appears on the World Anti-Doping Agency Prohibited List as a PPARδ agonist within the hormone and metabolic modulators category. Sports organizations test for it because it has been detected in athlete samples and seized products. Regulatory actions against marketed research chemical versions have occurred in several countries, though enforcement varies. Availability through unregulated channels complicates oversight.
Analytical laboratories typically identify cardarine and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is a common matrix in anti-doping testing, while blood and tissue may be used in research settings. Detection windows depend on the assay, the sample matrix, and the compound's metabolism. Because cardarine is extensively metabolized, laboratories often target specific metabolites to improve sensitivity and confirmation. Reference standards are required for reliable quantification. Method validation includes checks for selectivity, linearity, and carryover.
A persistent misconception is that cardarine is a fat-burning drug or a safe alternative to anabolic steroids. No approved therapeutic product exists, and human safety data are limited. The tumor findings in rodents remain a central concern in scientific reviews. Products sold online may contain inaccurate labels, impurities, or different compounds entirely, which complicates any assessment of effects. Independent testing of such products has reported frequent mislabeling. For these reasons, discussions in the literature emphasize risks and unknowns rather than benefits.
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.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved for human therapeutic use | No marketing authorization identified in major jurisdictions. |
| Anti-doping class | PPARδ agonist; hormone and metabolic modulators | Listed on the WADA Prohibited List. |
| Common test matrix | Urine | Also blood and tissue in research settings. |
| Typical analytical method | LC-MS/MS | Targets parent compound and metabolites. |
| Major safety signal | Tumor findings in rodents | Human relevance not established; limited human data. |
Activation of PPARδ changes transcription of genes involved in fatty acid transport, mitochondrial function, and skeletal muscle fuel preference. In rodent studies, pharmacological PPARδ activation was associated with increased endurance and altered body composition. These findings generated interest in performance enhancement, but species differences and study designs limit direct extrapolation to humans. Small human trials were conducted in the 2000s and later discontinued. The extent to which cardarine produces similar metabolic or performance effects in people remains an open question.
The compound is typically described as a laboratory compound rather than a therapeutic product. Published reports have explored its role in lipid disorders, insulin sensitivity, and exercise metabolism, yet no major drug regulator has approved it for medical use. Commercial samples sold under the cardarine name may vary in purity and identity. Analytical confirmation is therefore necessary when the material is discussed in scientific or regulatory contexts. Its classification as a prohibited substance in sport further shapes how it is studied and reported.
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.
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.
Adverse reactions from acupuncture, which are unusual and uncommon in typical acupuncture practice, included syncope, galactorrhoea, bilateral nystagmus, pyoderma gangrenosum, hepatotoxicity, eruptive lichen planus, and spontaneous needle migration. A 2013 systematic review found 31 cases of vascular injuries caused by acupuncture, three causing death. Two died from pericardial tamponade and one was from an aortoduodenal fistula. The same review found vascular injuries were rare, bleeding and pseudoaneurysm were most prevalent. A 2011 systematic review (without restriction in time or language), aiming to summarize all reported case of cardiac tamponade after acupuncture, found 26 cases resulting in 14 deaths, with little doubt about cause in most fatal instances. The same review concluded that cardiac tamponade was a serious, usually fatal, though theoretically avoidable complication following acupuncture, and urged training to minimize risk. A 2012 review found that a number of adverse events were reported after acupuncture in the UK's National Health Service (NHS), 95% of which were not severe, though miscategorization and under-reporting may alter the total figures. From January 2009 to December 2011, 468 safety incidents were recognized within the NHS organizations. The adverse events recorded included retained needles (31%), dizziness (30%), loss of consciousness/unresponsive (19%), falls (4%), bruising or soreness at needle site (2%), pneumothorax (1%) and other adverse side effects (12%).
Progressive difficulty swallowing (dysphagia) is present in 40 to 85% of IBM cases and often leads to death from aspiration pneumonia. IBM can also result in diminished capacity for aerobic exercise. This decline is most likely a consequence of the sedentary lifestyle leading to disuse muscle atrophy that is often associated with the symptoms of IBM (i.e. progressive muscle weakness, decreased mobility, and increased level of fatigue). Therefore, one focus of treatment should be the improvement of aerobic capacity. Patients with sIBM usually eventually need to resort to a cane or a walker and, in most cases, a wheelchair eventually becomes a necessity. "The progressive course of s-IBM leads slowly to severe disability. Finger functions can become very impaired, such as manipulating pens, keys, buttons, and zippers, pulling handles, and firmly grasping handshakes. Arising from a chair becomes difficult. Walking becomes more precarious. Sudden falls, sometimes resulting in major injury to the skull or other bones, can occur, even from walking on minimally irregular ground or from other minor imbalances outside or in the home, due to weakness of quadriceps and gluteus muscles depriving the patient of automatic posture maintenance. A foot-drop can increase the likelihood of tripping. Dysphagia can occur, usually caused by upper esophageal constriction that often can be symptomatically improved, for several months to years, by bougie dilation per a GI or ENT physician. Respiratory muscle weakness can sometimes eventuate."
=== International institutions, associations, and coordinations === Asia/Pacific Group on Money Laundering Moneyval, the Committee of Experts on the Evaluation of Anti–Money Laundering Measures and the Financing of Terrorism, a monitoring body of the Council of Europe Financial Action Task Force on Money Laundering Inter-Governmental Action Group against Money Laundering in West Africa Association of Certified Anti-Money Laundering Specialists
Sources: en.wikipedia.org
=== Water isotopes and climate === Based on the processes that fractionate isotopes in the water cycle, isotopic composition of meteoric water can be used to infer related environmental variables such as air temperature, precipitation amount, past elevations, lake levels, as well as to trace moisture sources. These studies form the field of isotope hydrology. Examples of isotope hydrology applications include:
== Anaerobic and aerobic metabolism == The term metabolism refers to the various series of chemical reactions that take place within the body. Aerobic refers to the presence of oxygen, whereas anaerobic means with a series of chemical reactions that does not require the presence of oxygen. The ATP-CP series and the lactic acid series are anaerobic, whereas the oxygen series is aerobic.
== Selected-reaction monitoring chromatogram (SRM, MRM) == The selected-reaction monitoring (SRM) experiment is very similar to the SIM experiment except that tandem mass spectrometry is used and a specific product ion of a specific parent ion is detected. The mass of the parent analyte is first selected while other ions are filtered away. The parent analyte ion is then fragmented in the gas phase and a specific fragment ion is monitored. This experiment has very high specificity because the SRM chromatogram represents only ions of a particular mass that fragment in a manner that produce a very specific product mass. This type of experiment can only be performed using tandem mass spectrometry. The technology progress in the MS/MS area lead to the development of MRM, Multiple Reaction Monitoring, which allows simultaneous detection of several coeluting analytes with different parent and/or product ions.
== Receptors == Most hormones initiate a cellular response by initially binding to either cell surface receptors or intracellular receptors. A cell may have several different receptors that recognize the same hormone but activate different signal transduction pathways, or a cell may have several different receptors that recognize different hormones and activate the same biochemical pathway. Receptors for most peptide as well as many eicosanoid hormones are embedded in the cell membrane as cell surface receptors, and the majority of these belong to the G protein-coupled receptor (GPCR) class of seven alpha helix transmembrane proteins. The interaction of hormone and receptor typically triggers a cascade of secondary effects within the cytoplasm of the cell, described as signal transduction, often involving phosphorylation or dephosphorylation of various other cytoplasmic proteins, changes in ion channel permeability, or increased concentrations of intracellular molecules that may act as secondary messengers (e.g., cyclic AMP). Some protein hormones also interact with intracellular receptors located in the cytoplasm or nucleus by an intracrine mechanism. For steroid or thyroid hormones, their receptors are located inside the cell within the cytoplasm of the target cell. These receptors belong to the nuclear receptor family of ligand-activated transcription factors. To bind their receptors, these hormones must first cross the cell membrane. They can do so because they are lipid-soluble.
Sources: en.wikipedia.org
No. Cardarine has not received approval for human therapeutic use in major jurisdictions. It remains an investigational compound.
It is classified as a PPARδ agonist on the WADA Prohibited List. Anti-doping laboratories can detect it and its metabolites in urine. Its use is banned in competition and usually out of competition.
Rodent studies reported increased tumor incidence at multiple sites. The human relevance remains uncertain, but the findings contributed to discontinuation of development. No long-term human cancer data are available.
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.