A practical reference on Prohibited substance: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-12-11 and is reviewed periodically as new material appears.
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.
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 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.
| Property | Value | Notes |
|---|---|---|
| IUPAC name | {4-[({4-methyl-2-[4-(trifluoromethyl)phenyl]-1,3-thiazol-5-yl}methyl)sulfanyl]phenoxy}acetic acid | Systematic name for GW501516 |
| CAS Registry Number | 317318-70-0 | Unique identifier for the parent compound |
| Molecular formula | C21H18F3NO3S2 | Includes carbon, hydrogen, fluorine, nitrogen, oxygen, and sulfur |
| Molecular weight | 453.5 g/mol | Approximate value for the neutral form |
| Appearance | White to off-white powder | Typical description for purified laboratory material |
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.
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 studied for its effects on lipid and glucose metabolism. It functions as an agonist at peroxisome proliferator-activated receptor delta, or PPARδ, a nuclear receptor that influences gene expression. The molecule is not a steroid, nor is it a selective androgen receptor modulator. It is also known in research and sports literature as GW-501516 and endurobol. Early laboratory work examined its metabolic activity in cell cultures and animal models.
==== Adrenocorticotropic hormone ==== Adrenocorticotropic hormone (ACTH), a pituitary peptide, also has some stimulating effect on aldosterone, probably by stimulating the formation of deoxycorticosterone, a precursor of aldosterone. Aldosterone is increased by blood loss, pregnancy, and possibly by further circumstances such as physical exertion, endotoxin shock, and burns.
Emulsions are used to manufacture polymer dispersions – polymer production in an emulsion 'phase' has a number of process advantages, including prevention of coagulation of product. Products produced by such polymerisations may be used as the emulsions – products including primary components for glues and paints. Synthetic latexes (rubbers) are also produced by this process.
== Growth == The optimal growth temperature range for B. cereus is 30–40 °C (86–104 °F). At 30 °C , a population of B. cereus can double in as little as 20 minutes or as long as 3 hours, depending on the food product. Spores of B. cereus are not metabolically active, but can rapidly become active and begin replicating once they encounter adequate growth conditions.
Serotonin–norepinephrine reuptake inhibitors (SNRIs) are a class of antidepressant medications used to treat major depressive disorder (MDD), anxiety disorders, chronic neuropathic pain, fibromyalgia, and menopausal symptoms. Off-label uses include treatments for attention deficit hyperactivity disorder (ADHD) and obsessive–compulsive disorder (OCD). SNRIs are monoamine reuptake inhibitors; specifically, they inhibit the reuptake of serotonin and norepinephrine. These neurotransmitters are thought to play an important role in mood regulation. SNRIs can be contrasted with the selective serotonin reuptake inhibitors (SSRIs) and norepinephrine reuptake inhibitors (NRIs), which act upon single neurotransmitters. Since norepinephrine pathways play a role in pain modulation, SNRIs are also widely used for chronic pain conditions such as neuropathic pain and fibromyalgia. The human serotonin transporter (SERT) and norepinephrine transporter (NET) are membrane transport proteins that are responsible for the reuptake of serotonin and norepinephrine from the synaptic cleft back into the presynaptic nerve terminal. Dual inhibition of serotonin and norepinephrine reuptake can offer advantages over other antidepressant drugs by treating a wider range of symptoms. They can be especially useful in concomitant chronic or neuropathic pain. SNRIs, along with SSRIs and NRIs, are second-generation antidepressants.
== Structure–activity relationship == Even though μ-opioid receptor (MOR) targeting drugs have been used for a long time, not much is known about the structure-activity relationship and the ligand-receptor interactions on the basis of well-defined biological effects on receptor activation or inhibition. Also, the distinction in the receptor-ligand interaction patterns of agonists and antagonists is not known for sure. One theory states that the morphinans biological activity could be determined by the size of the N-substituents. For example, antagonists usually have larger substituents, such as allyl- or cyclopropyl methyl at the morphinan nitrogen, while agonists generally contain a methyl group. On the other hand, agonist activity is also shown in ligands with larger groups at the morphinan nitrogen, and therefore this hypothesis is challenged.
Sources: en.wikipedia.org
=== Seed germination === There are two types of seed within each pod – reddish-dark and dark (black). The ratio between these seeds varies from 1:20 to 1:5, with darker seeds outnumbering lighter seeds. Reddish-dark seeds have a thinner coat and they germinate earlier than black seeds that have not first been acid treated. "Dark seeds have a harder seed coat and require various pretreatments to ensure good germination rates." Although the seeds' usual germination rate has been reported at 75%, germination can be improved by scalding for about 7 minutes, then soaking seeds in hot water overnight prior to planting. Locust tree seedlings "can be established vegetatively in nursery beds by grafting or budding, or by rooting adult cuttings." These methods have shown good results in 11- to 25-year-old trees in Burkina Faso and Nigeria.
=== Muscle spindles === The muscle spindle is a proprioceptive organ that lies embedded in the muscle. It is a 1-3mm long encapsulated, fusiform (spindle-shaped) structure comprising contractile intrafusal (inside the spindle) muscle fibers and a central non-contractile region. There are three types of intrafusal fiber: bag I, bag-II and chain, which correspond to the dynamic and static responses of the afferents they influence. Spindles relay information through primary (Group Ia) and secondary (Group II) sensory afferents. Primary afferents innervate nuclear bag and chain intrafusal muscle fibers in the central region and secondary afferents innervate nuclear chain fibers at the ends of the spindle.. Spindles encode extrafusal muscle length, velocity and acceleration. Recent studies suggest that they respond to the force and yank (the first time-derivative of force) exerted on intrafusal muscle. Nonlinear features of muscle spindle responses to muscle stretch include initial bursts, history-dependence, and rate relaxation. Initial bursts occur at the onset of stretch and only last a very short time. History dependence refers to how the response of muscle spindles is affected by past stretch inputs. Rate relaxation refers to how the firing rate of muscle spindles decreases over time when held at a constant length.
==== Other methods of hydrogen storage ==== There are six possible methods that can be used for the reversible storage of hydrogen with a high volumetric and gravimetric density, which are summarized in the following table, (where ρm is the gravimetric density, ρv is the volumetric density, T is the working temperature, and P is the working pressure):
=== Use of multi-amino acid scores === While the DIAAS has come to supersede the PDCAAS as the measurement of choice, the original recommendation of the FAO when proposing the DIAAS was that each essential amino acid be treated as a separate nutrient. This would eliminate the need to consider protein content or quality, and would arguably simplify the analysis of the nutrition of meals rather than individual foods. One proposal along these lines is the EAA-9 score, which would measure the percent of RDI of the limiting amino acid of a serving of food. These would be used to determine the EAA-9 Equivalence Serving, or the amount of a food necessary to provide the same amount of that amino acid as an egg.
Sources: en.wikipedia.org
=== Chemical === Trehalose is a nonreducing sugar formed from two glucose units joined by a 1–1 alpha bond, giving it the name α-D-glucopyranosyl-(1→1)-α-D-glucopyranoside. The bonding makes trehalose very resistant to acid hydrolysis, and therefore is stable in solution at high temperatures, even under acidic conditions. The bonding keeps nonreducing sugars in closed-ring form, such that the aldehyde or ketone end groups do not bind to the lysine or arginine residues of proteins (a process called glycation). Trehalose is less soluble than sucrose, except at high temperatures (>80 °C). Trehalose forms a rhomboid crystal as the dihydrate, and has 90% of the calorific content of sucrose in that form. Anhydrous forms of trehalose readily regain moisture to form the dihydrate. Anhydrous forms of trehalose can show interesting physical properties when heat-treated. Trehalose aqueous solutions show a concentration-dependent clustering tendency. Owing to their ability to form hydrogen bonds, they self-associate in water to form clusters of various sizes. All-atom molecular dynamics simulations showed that concentrations of 1.5–2.2 molar allow trehalose molecular clusters to percolate and form large and continuous aggregates. Trehalose directly interacts with nucleic acids, facilitates melting of double stranded DNA and stabilizes single-stranded nucleic acids.
=== Clinical utility === Both in the FAST study, an observational case-control sequencing study including 300 persons from Germany, and in a large sample from the NHANES study, SPINA-GR differed more clearly between subjects with and without diabetes than the corresponding HOMA-IR, HOMA-IS and QUICKI indices.
=== Atpase's catalytic mechanism === Actin is an ATPase, which means that it is an enzyme that hydrolyzes ATP. This group of enzymes is characterised by their slow reaction rates. It is known that this ATPase is "active", that is, its speed increases by some 40,000 times when the actin forms part of a filament. A reference value for this rate of hydrolysis under ideal conditions is around 0.3 s−1. Then, the Pi remains bound to the actin next to the ADP for a long time, until it is cooperatively liberated from the interior of the filament. The exact molecular details of the catalytic mechanism are still not fully understood. Although there is much debate on this issue, it seems certain that a "closed" conformation is required for the hydrolysis of ATP, and it is thought that the residues that are involved in the process move to the appropriate distance. The glutamic acid Glu137 is one of the key residues, which is located in subdomain 1. Its function is to bind the water molecule that produces a nucleophilic attack on the ATP's γ-phosphate bond, while the nucleotide is strongly bound to subdomains 3 and 4. The slowness of the catalytic process is due to the large distance and skewed position of the water molecule in relation to the reactant. It is highly likely that the conformational change produced by the rotation of the domains between actin's G and F forms moves the Glu137 closer allowing its hydrolysis. This model suggests that the polymerization and ATPase's function would be decoupled straight away.
== Antiviral drug resistance == Antiviral resistance can be defined by a decreased susceptibility to a drug caused by changes in viral genotypes. In cases of antiviral resistance, drugs have either diminished or no effectiveness against their target virus. The issue inevitably remains a major obstacle to antiviral therapy as it has developed to almost all specific and effective antimicrobials, including antiviral agents. The Centers for Disease Control and Prevention (CDC) inclusively recommends anyone six months and older to get a yearly vaccination to protect them from influenza A viruses (H1N1) and (H3N2) and up to two influenza B viruses (depending on the vaccination). Comprehensive protection starts by ensuring vaccinations are current and complete. However, vaccines are preventative and are not generally used once a patient has been infected with a virus. Additionally, the availability of these vaccines can be limited based on financial or locational reasons which can prevent the effectiveness of herd immunity, making effective antivirals a necessity. The three FDA-approved neuraminidase antiviral flu drugs available in the United States, recommended by the CDC, include: oseltamivir (Tamiflu), zanamivir (Relenza), and peramivir (Rapivab). Influenza antiviral resistance often results from changes occurring in neuraminidase and hemagglutinin proteins on the viral surface. Currently, neuraminidase inhibitors (NAIs) are the most frequently prescribed antivirals because they are effective against both influenza A and B.
The last TRNA validated by the small ribosomal subunit (accommodation) transfers the amino acid. It carries to the large ribosomal subunit which binds it to one of the preceding admitted TRNA (transpeptidation). The ribosome then moves to the next mRNA codon to continue the process (translocation), creating an amino acid chain. In bacterial translation, and archaeal translation, translation occurs in the cytosol, where the ribosome binds to the mRNA. In eukaryotes, translation can occur in the cytoplasm and also across the membrane of the endoplasmic reticulum through a process called co-translational translocation. In co-translational translocation, the entire ribosome–mRNA complex binds to the outer membrane of the rough endoplasmic reticulum (ER), and the new protein is synthesized and released into the ER; the newly created polypeptide can be immediately secreted or stored inside the ER for future vesicle transport and secretion outside the cell. Many types of transcribed RNA, such as TRNA, ribosomal RNA, and small nuclear RNA, do not undergo a translation into proteins. Several antibiotics act by inhibiting translation. These include Anisomycin, cycloheximide, chloramphenicol, tetracycline, streptomycin, erythromycin, and puromycin. Prokaryotic ribosomes have a different structure from that of eukaryotic ribosomes, and thus antibiotics can specifically target bacterial infections without harming a eukaryotic host's cells.
Sources: en.wikipedia.org
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.
It is prohibited by the World Anti-Doping Agency as a hormone and metabolic modulator. Athletes who test positive for GW501516 can face sanctions, including suspensions and loss of results.
Cardarine is a common or trade-style name, while GW501516 is the research code for the same chemical entity. Some sources also use Endurobol or GSK-516. The names refer to the same compound, not distinct drugs.
No. Cardarine has not received approval for human therapeutic use in major jurisdictions. It remains an investigational compound.