Carcinogenicity is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Last reviewed on 2026-02-05. Where a claim depends on a specific study, the study is described rather than over-claimed.
Early clinical research explored GW501516 for lipid disorders, obesity, and diabetes. Some short-term human studies reported changes in HDL cholesterol, LDL cholesterol, and triglycerides. The development program was discontinued after rodent studies showed dose-dependent tumor formation in multiple tissues, including liver, bladder, stomach, and skin. These findings raised concerns about long-term cancer risk in humans. Because human exposure data are limited, the clinical significance of the rodent tumors remains uncertain.
Literature on cardarine often separates receptor pharmacology from toxicology. Mechanistic papers describe PPARδ activation and gene expression changes, while safety assessments focus on carcinogenicity and species differences. Questions remain about whether rodent tumors arise through PPARδ-dependent or off-target mechanisms. Another open area is how human metabolism and exposure compare with those in animal studies. Analytical methods such as liquid chromatography–mass spectrometry are used to confirm identity in biological and product samples.
GW501516 acts as an agonist at the peroxisome proliferator-activated receptor delta, a nuclear receptor that regulates gene expression. Activation shifts transcription toward genes involved in fatty acid uptake, oxidation, and energy expenditure. The compound does not bind the androgen receptor and therefore differs from anabolic steroids and SARMs. In rodent models, this metabolic shift has been linked to increased running endurance and reduced fat accumulation. The exact downstream pathways in humans remain incompletely characterized.
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.
| Property | Value | Notes |
|---|---|---|
| Primary target | PPARδ | Nuclear receptor; not androgen receptor |
| Studied indications | Dyslipidemia; obesity; diabetes | Early clinical research; development discontinued |
| Rodent toxicity | Tumor formation in multiple tissues | Dose-dependent findings in some studies |
| Human approval | None | No approved therapeutic use |
| Typical analytical method | LC-MS/MS | Used for identity and quantification |
Safety concerns emerged from long-term animal studies. In rodents given the compound for extended periods, researchers found an increased incidence of certain cancers, including liver and bladder tumors. These findings contributed to the discontinuation of clinical development. Whether similar risks apply to short-term or low-level exposure in humans is not established, and controlled human safety data are limited. The relevance of high-dose rodent carcinogenicity findings to human use remains a subject of debate.
Human trials of GW501516 were small and short in duration. They examined lipid levels, glucose handling, and other metabolic markers, but the programs were halted after the animal cancer findings. No approved therapeutic product exists, and published human data are insufficient for establishing long-term safety. Reports of use for athletic performance come mainly from non-clinical settings and cannot be verified through controlled trials. Independent testing of products sold as cardarine has found inconsistent purity and labeling.
Laboratory studies indicate that GW501516 activates PPARδ, a nuclear receptor involved in fatty acid oxidation and energy metabolism. In rodent experiments, treated animals often showed increased endurance and reduced fat mass. These effects were observed under controlled conditions and do not establish safe or effective use in humans. The exact dose-response relationship in humans remains poorly characterized. Species differences in metabolism can affect how results translate across animals and people.
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.
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.
== Chemistry == Volufralin is a semisynthetic analogue of limonoids from Neobeguea mahafalensis root bark such as libiguin A and libiguin B. Neobeguea mahafalensis has a long history of traditional use in Madagascar. In 2014, libiguin A and B were discovered via isolation from the roots of the plant and were found to cause "profound enhancement of sexual activity" in rodents. This specifically included having very high potency and a remarkably long-lasting duration in increasing mounting behavior in male rodents.
1936: The first all-steel reefers entered service. 1946: Two experimental aluminum-body refrigerator cars entered service on the PFE; an experimental reefer with a stainless-steel body was built for the SFRD. 1950: The U.S. refrigerator car roster dropped to 127,200. 1957: The last ice bunker refrigerator cars were built. 1958: The first mechanical reefers (using diesel-powered refrigeration units) entered revenue service. 1959: The flush, "plug" style sliding door was introduced as an option, providing a larger door to ease loading and unloading. The tight-fitting doors were better insulated, helping the car maintain a more even temperature. An early example is the DT&I XL-1 car by Evans. 1966: Japanese National Railways started operation of fish freight express trains by newly built "resa 10000" type refers. 1969: ACF constructed several experimental center flow hopper cars incorporating mechanical cooling systems and insulated cargo cells. The units were intended for shipping bulk perishables. 1971: The last ice-cooled reefers were retired. 1980: The U.S. refrigerator car roster dropped to 80,000. 1986: The last reefers in Japan were replaced by reefer containers. 1990s: The first cryogenically cooled reefers entered service. 2001: The number of refrigerator cars in the United States bottomed out at approximately 8,000. 2005: The number of reefers in the United States climbs to approximately 25,000, due to significant new refrigerator car orders. 2006: Railex launches 55-car unit train reefer service between the U.S. West Coast and New York.
=== Synthetic glycerol === Although more expensive than production from plant or animal triglycerides, glycerol can be synthesized by various routes. During World War II, synthetic glycerol processes became a national defense priority because it is a precursor to nitroglycerin. Epichlorohydrin is the most important precursor. Chlorination of propylene gives allyl chloride, which is oxidized with hypochlorite to dichlorohydrin, which reacts with a strong base to give epichlorohydrin. Epichlorohydrin can be hydrolyzed to glycerol. Chlorine-free processes from propylene include the synthesis of glycerol from acrolein and propylene oxide.
Sources: en.wikipedia.org
The families of two missing people from Trinidad and Tobago identified them publicly and suspected they were killed in the 14 October strike; one family said their relative was a fisherman who traveled often to Venezuela and denied he was involved in trafficking drugs. MSNBC wrote that one had a drug-related charge from 2018, and the other had been released in 2021 after a prison sentence for a 2009 murder. In the Paria Peninsula of Sucre state in Venezuela, from which the first boat struck on 1 September allegedly originated, Venezuelan media reported the area was known for trafficking, although not necessarily by Tren de Aragua, and some family members stated that villagers had become involved in illicit activity out of economic necessity. Inhabitants describing a town in mourning published tributes containing photos of the deceased beginning early on 3 September. The deceased included eight persons from San Juan de Unare and three from a nearby town, Güiria. The New York Times reported that "Venezuelan security officials descended on San Juan de Unare, cut off the electricity and made clear that public pronouncements about the attacks were not welcome, according to four townspeople, including the niece of one of the victims." Associated Press journalist Regina Garcia Cano visited Sucre just after the first Venezuelan strike and interviewed dozens of people; she wrote of the "sources' very real fears of being punished—particularly by the Venezuelan government—for speaking to reporters".
== Nanofactories == A nanofactory is a proposed system in which nanomachines (resembling molecular assemblers, or industrial robot arms) would combine reactive molecules via mechanosynthesis to build larger atomically precise parts. These, in turn, would be assembled by positioning mechanisms of assorted sizes to build macroscopic (visible) but still atomically-precise products. A typical nanofactory would fit in a desktop box, in the vision of K. Eric Drexler published in Nanosystems: Molecular Machinery, Manufacturing and Computation (1992), a notable work of "exploratory engineering". During the 1990s, others have extended the nanofactory concept, including an analysis of nanofactory convergent assembly by Ralph Merkle, a systems design of a replicating nanofactory architecture by J. Storrs Hall, Forrest Bishop's "Universal Assembler", the patented exponential assembly process by Zyvex, and a top-level systems design for a 'primitive nanofactory' by Chris Phoenix (director of research at the Center for Responsible Nanotechnology). All of these nanofactory designs (and more) are summarized in Chapter 4 of Kinematic Self-Replicating Machines (2004) by Robert Freitas and Ralph Merkle. The Nanofactory Collaboration, founded by Freitas and Merkle in 2000, is a focused, ongoing effort involving 23 researchers from 10 organizations and 4 countries that is developing a practical research agenda specifically aimed at positionally-controlled diamond mechanosynthesis and diamondoid nanofactory development.
United States Court of Appeals, Eighth Circuit. Decided Oct. 31, 1979. LAY, Circuit Judge. John Arthur Stieren appeals from the judgment of conviction for possession of cocaine with intent to distribute and dispense under 21 U.S.C. § 841(a)(1). Stieren contends that the statute is unconstitutional because "cocaine is classified as a narcotic under Schedule II of 21 U.S.C. § 812(c) when as a matter of scientific and medical fact cocaine is not a narcotic but is a non-narcotic stimulant." The sufficiency of the evidence is not disputed. Stieren was convicted after special agents testified that he had and attempted to sell them a large quantity of cocaine. Defendant urges that the testimony and reports by physicians and scientists demonstrate that cocaine is not a narcotic. He also cites cases that hold that cocaine is not a narcotic under the pharmacological definition of the term. State v. Erickson, 574 P.2d 1 (Alaska 1978). It is within the legislative prerogative to classify cocaine, which is a non-narcotic central nervous system stimulant, as a narcotic for penalty and regulatory purposes. 21 U.S.C. § 802(16)(A). The use of cocaine poses serious problems for the community and has a high potential for abuse. Congress's choice of penalty reflects a societal policy that must be adhered to by the courts.2 Congress has the power to reclassify cocaine. This power has been delegated to the Attorney General. 21 U.S.C. § 811(a)(1). If cocaine is to be reclassified, the defendant's arguments should be made to the legislative branch, not the courts.
== Contraindications == The varicella vaccine is not recommended for seriously ill people, pregnant women, people who have tuberculosis, people who have experienced a serious allergic reaction to the varicella vaccine in the past, people who are allergic to gelatin, people allergic to neomycin, people receiving high doses of steroids, people receiving treatment for cancer with x-rays or chemotherapy, as well as people who have received blood products or transfusions during the past five months. Additionally, the varicella vaccine is not recommended for people who are taking salicylates (e.g. aspirin). After receiving the varicella vaccine, the use of salicylates should be avoided for at least six weeks. The varicella vaccine is also not recommended for individuals who have received a live vaccine in the last four weeks, because live vaccines that are administered too soon within one another may not be as effective. It may be usable in people with HIV infections who have a good blood count and are receiving appropriate treatment. Specific antiviral medication, such as acyclovir, famciclovir, or valacyclovir, are not recommended 24 hours before and 14 days after vaccination.
Sources: en.wikipedia.org
=== Clinical social work === Social workers provide a variety of services, generally concerned with social problems, their causes, and their solutions. With specific training, clinical social workers may also provide psychological counseling (in the US and Canada), in addition to more traditional social work.
=== Surfactant peptides === Surfactant–like peptides that undergo self-assembly in water to form nanotubes and nanovesicles have been designed using natural lipids as guides. This class of peptides has a hydrophilic head (with one or two charged amino acids such as aspartic or glutamic acids, or lysine or histidine acids) with a hydrophobic tail (with 4 or more hydrophobic amino acids such as alanine, valine, or leucine). The peptide monomers are about 2-3 nm long and consist of seven or eight amino acids; the peptide length can be adjusted by adding or removing acids. In water, surfactant peptides undergo self-assembling to form well-ordered nanotubes and nanovesicles of 30–50 nm through intermolecular hydrogen bonds and the packing of the hydrophobic tails in between the residues, like micelle formation. Transmission electron microscopy examination on quick-frozen samples of surfactant-peptide structures showed helical open-ended nanotubes. The samples also showed dynamic behaviours and some vesicle "buds" sprouting out of the peptide nanotubes.
== Recreational use == As dihydrocodeine can provide a euphoric high when taken in higher-than-therapeutic doses, it is quite commonly used recreationally. The typical recreational dose can be anything from 70 mg to 500 mg, or, in users with tolerance, even more. Potentiators and adjuvants are often included when dihydrocodeine is used in an unsupervised fashion, especially carisoprodol, glutethimide, hydroxyzine and first-generation antihistamines, both to intensify the effect and lessen side-effects such as itching.
=== Medical === Dihydromorphine is used for the management of moderate to severe pain such as that occurring in cancer; however, it is less effective in treating neuropathic pain and is generally considered inappropriate and ineffective for psychological pain.
17 January – A study in Nature finds that the Greenland ice sheet is melting 20% faster than previously estimated, due to the effects of calving-front retreat. The loss of 30m tonnes of ice an hour is "sufficient to affect ocean circulation and the distribution of heat energy around the globe." 18 January NASA reports the end of the Ingenuity helicopter's operation, after 72 successful flights on Mars, due to a broken rotor blade. A potential candidate for the first known radio pulsar-black hole binary is reported by astronomers. The heavier of the two lies in the "mass gap" between neutron stars and black holes. The pair are located in the globular cluster NGC 1851. Two insect-like robots, a mini-bug and a water strider, are reported as being the smallest, lightest, and fastest fully-functional micro-robots ever created. Bottom trawling is found to release 340 million tonnes of carbon dioxide (CO2) into the atmosphere each year, nearly 1 percent of all global CO2 emissions in addition to acidifying oceans. 19 January – Japan becomes the fifth country to achieve a soft landing on the Moon, with its SLIM mission. 21 January – Biologists report the discovery of "obelisks", a new class of viroid-like elements, and "oblins", their related group of proteins, in the human microbiome. 23 January – A viable and sustainable approach for gold recovery from e-waste is demonstrated.
Sources: en.wikipedia.org
It targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not act primarily on androgen receptors. This distinction separates it from SARMs.
Rodent studies found dose-dependent tumors in several organs. The sponsor discontinued the program over cancer concerns. Human risk from long-term use remains unknown.
Controlled human endurance trials are lacking. Animal studies show increased exercise capacity under some conditions. Anecdotal reports are not equivalent to clinical evidence.
Cardarine is an investigational synthetic compound that acts as a PPARδ agonist. It is also known as GW501516 and has been studied mainly in preclinical research. It is not an approved medicine.