The short version of clinical development fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-06-22 and is reviewed periodically as new material appears.
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.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Primary target | PPARδ (NR1C2) | Nuclear receptor involved in lipid metabolism |
| Preclinical effect | Increased fatty acid oxidation | Observed in rodent studies |
| Key safety signal | Tumors in rodents after long-term exposure | Contributed to halted clinical development |
| Human trial status | No approved product; development stopped | Limited short-term metabolic data |
| Sport regulatory status | Prohibited at all times | WADA hormone and metabolic modulators class |
Laboratory studies have examined GW501516 in cell cultures and rodents for conditions such as dyslipidemia, insulin resistance, and obesity. Some trials in humans were initiated, but development was discontinued after preclinical findings raised concerns about cancer in certain models. Those findings do not prove that the compound causes cancer in people, but they contributed to regulatory caution. Later reviews often describe the evidence as preliminary and insufficient for assessing long-term safety.
In the fitness and bodybuilding literature, cardarine is frequently discussed as an endurance agent or fat-loss compound, although such claims are not supported by robust clinical evidence. Online descriptions often mix animal data, user anecdotes, and marketing language. Researchers who study PPARδ agonists distinguish between receptor activation in controlled experiments and unsupervised use of unverified products. The latter introduces unknown purity, dose, and interactions, making reported experiences difficult to interpret scientifically.
Cardarine is a common name for GW501516, a synthetic compound developed in the 1990s through research collaborations involving GlaxoSmithKline. It belongs to a class of molecules known as peroxisome proliferator-activated receptor delta agonists. Early studies explored its effects on lipid metabolism and energy expenditure in animal models. The compound was never approved as a human medicine, and clinical development was discontinued. In the years since, it has appeared in fitness and bodybuilding communities as a performance-enhancing substance. Regulatory agencies classify it as an unapproved drug.
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.
== Tuftsin analogues == Tuftsin sequence appears in all four classes of IgG. However, only leukokinin, a small fraction of IgG1, displays tuftsin activity. Tuftsin occurs in guinea pig IgG2 exactly in the same position. The mouse IgG1 analogue is a tetrapeptide Thr-Gln-Pro-Arg (TQPR) at the same place, one base change at the first base of the triplet code. Tuftsin sequence appears in residues 9-12 from the amino terminal of p12 protein of Rauscher murine leukemia virus. The tetrapeptide Thr-Arg-Pro-Lys (TRPK) is in the influenza hemagglutinin virus protein, residues 214–217. The canine analogue is the tetrapeptide Thr-Lys-Pro-Lys (TKPK). The peptide Thr-Arg-Pro-Arg (TRPR) is a biologically active pancreatic polypeptide 32–35 with gastrointestinal functions. Thr-Arg-Pro-Arg, Thr-Lys-Pro-Lys, Thr-Arg-Pro-Lys are as active as Thr-Lys-Pro-Arg. Thr-Lys-Pro-Pro-Arg (TKPPR) is a potent inhibitor. Lys-Pro-Pro-Arg (KPPR) is also an inhibitor of phagocytosis, superoxide anion production and chemotaxis both human and rat PMN leukocytes and monocytes. Tyr-Lys-Pro exert considerable regulatory effect on several macrophage functions including: phagocytosis, cell locomotion, superoxide anion production, IgE-dependent cellular cytotoxicity, β-glycuronidase release, and IL-1 production. Selank is an elongated version of tuftsin with a Pro-Gly-Pro appended, i.e. Thr-Lys-Pro-Arg-Pro-Gly-Pro (TKPRPGP). It has been claimed to have anti-anxiety and nootropic effects and is used in Russia and other former Soviet bloc countries.
== History == In 1935, Hans Adolf Krebs discovered D-amino acid oxidase after an experiment with porcine kidney homogenates and amino acids. Shortly after, Warburg and Christian observed the oxidase had a FAD cofactor making it the second flavoenzyme to be discovered. In the upcoming years other scientists developed and improved the purification procedure for a porcine D-amino acid oxidase. In 1983, inhibitors for the oxidase were discovered. In 2006, the 3D structure of the oxidase was published. Currently, the link between human D-amino acid oxidase (hDAAO) activity and schizophrenia is being researched.
The four substrates of this enzyme are 1-deoxy-11-oxopentalenic acid, reduced nicotinamide adenine dinucleotide phosphate (NADPH), oxygen, and a proton. It products are neopentalenolactone D, oxidised NADP+, and water. The starting ketone is made as part of a biosynthetic pathway in Streptomyces avermitilis which leads to pentalenolactone and related compounds. The enzyme is a Baeyer-Villiger monooxygenase that uses flavin adenine dinucleotide as a cofactor.
Sources: en.wikipedia.org
=== True protein === In at least one segment of the food industry, the dairy industry, some countries (at least the U.S., Australia, France and Hungary) have adopted "true protein" measurement, as opposed to crude protein measurement, as the standard for payment and testing: "True protein is a measure of only the proteins in milk, whereas crude protein is a measure of all sources of nitrogen and includes nonprotein nitrogen, such as urea, which has no food value to humans. ... Current milk-testing equipment measures peptide bonds, a direct measure of true protein." Measuring peptide bonds in grains has also been put into practice in several countries including Canada, the UK, Australia, Russia and Argentina where near-infrared reflectance (NIR) technology, a type of infrared spectroscopy is used. The more traditional approach to true protein analysis is amino acid analysis. Data from such analysis has additional nutritional meaning, as humans and other animals have specific requirements for essential amino acids. The Food and Agriculture Organization of the United Nations (FAO) recommends that only amino acid analysis be used to determine protein in, inter alia, foods used as the sole source of nourishment, such as infant formula, but also provides: "When data on amino acids analyses are not available, determination of protein based on total N content by Kjeldahl (AOAC, 2000) or similar method ...
Fluid statics or hydrostatics is the branch of fluid mechanics that studies fluids at rest. It embraces the study of the conditions under which fluids are at rest in stable equilibrium; and is contrasted with fluid dynamics, the study of fluids in motion. Hydrostatics offers physical explanations for many phenomena of everyday life, such as why atmospheric pressure changes with altitude, why wood and oil float on water, and why the surface of water is always level whatever the shape of its container. Hydrostatics is fundamental to hydraulics, the engineering of equipment for storing, transporting and using fluids. It is also relevant to some aspects of geophysics and astrophysics (for example, in understanding plate tectonics and anomalies in the Earth's gravitational field), to meteorology, to medicine (in the context of blood pressure), and many other fields.
Specialized variants of field rations may exist for different environments, situations, and roles, such as cold-weather warfare, mountain warfare, jungle warfare, desert warfare, long-range reconnaissance patrols, and vehicle crew variants. The meals offered in a field ration often come in multiple different "menus" (varieties) predominantly featuring foods from a military's national or traditional cuisine—and, if diverse enough and possible under the constraints of a field ration, fusion cuisine such as soul food or Anglo-Indian cuisine—intended to evoke the "taste of home" while on deployment or away. Some rations include commercially available items, often snacks such as Tootsie Rolls, Charms, and Yorkie bars. However, basic or less-accommodating rations (usually emergency rations) may consist of very simple meals intended to provide enough nutrients and energy to keep a soldier combat-ready or alive, like compressed food bars. Field rations are commonly issued to land forces such as armies, marines, and air force ground forces, who may spend lengthy periods of time away from fixed food sources. Navies and air forces are not commonly issued field rations as they are closely attached to the rear or steady supplies of food, prepared in galleys aboard naval vessels and flight kitchens at air bases. Rations may still be issued to personnel in certain situations or roles, like long-range flight rations for bomber, transport, and reconnaissance aircraft crews, who could otherwise spend hours in flight without food.
The Tandem t:slim X2 insulin pump, made by Tandem Diabetes, can be integrated with the Dexcom G6 or Dexcom G7 Continuous Glucose Monitoring Systems to automate glucose regulation. Using real-time glucose data from the CGM, the t:slim X2 uses an algorithm to adjust insulin delivery based on these readings, helping to prevent glucose highs and lows. This integration enables more flexible management of blood sugar levels throughout the day. The t:slim X2 uses two predictive technologies when connected to the Dexcom CGM: Control-IQ and Basal-IQ. Control-IQ is a hybrid closed-loop system that predicts glucose levels up to 30 minutes in advance using Dexcom CGM data. It adjusts basal insulin delivery by increasing, decreasing, or halting insulin delivery as needed to maintain glucose levels within a target range. Additionally, Control-IQ can automatically administer up to one correction bolus per hour if glucose levels are expected to rise. Basal-IQ also uses Dexcom G6 data to predict glucose trends but primarily focuses on preventing lows. It stops insulin delivery if glucose is expected to drop below 4.4 mmol/L (72 mg/dL) and resumes delivery once glucose levels rise. However, Basal-IQ does not administer correction boluses or adjust insulin for elevated glucose levels.
Sources: en.wikipedia.org
The ability of birds to return to precise locations across vast distances has been known for some time; in an experiment conducted in the 1950s, a Manx shearwater released in Boston in the United States returned to its colony in Skomer, in Wales within 13 days, a distance of 5,150 km (3,200 mi). Birds navigate during migration using a variety of methods. For diurnal migrants, the sun is used to navigate by day, and a stellar compass is used at night. Birds that use the sun compensate for the changing position of the sun during the day by the use of an internal clock. Orientation with the stellar compass depends on the position of the constellations surrounding Polaris. These are backed up in some species by their ability to sense the Earth's geomagnetism through specialised photoreceptors.
{\displaystyle {\frac {\partial W}{\partial t}}+U{\frac {\partial W}{\partial X}}+W{\frac {\partial W}{\partial Z}}\ =-{\frac {1}{\rho _{o}}}{\frac {\partial p_{d}}{\partial Z}}+v\left({\frac {\partial ^{2}W}{\partial X^{2}}}+{\frac {\partial ^{2}W}{\partial Z^{2}}}\right)\ -g\left(\beta _{s}\nabla {S}-\beta _{T}\nabla {T}\right)}
A 2015 PHE report found that high levels of formaldehyde only occurred in overheated "dry-puffing", and that "dry puffs are aversive and are avoided rather than inhaled", and "At normal settings, there was no or negligible formaldehyde release." A 2018 study confirmed e-cigarettes can emit formaldehyde at high levels more than 5 times higher than what is reported for cigarette smoke) at moderate temperatures and under conditions that have been reported to be non-averse to users. But e-cigarette users may "learn" to overcome the unpleasant taste due to elevated aldehyde formation, when the nicotine craving is high enough. High voltage e-cigarettes are capable of producing large amounts of carbonyls. Reduced voltage (3.0 V) e-cigarettes had e-cigarette aerosol levels of formaldehyde and acetaldehyde roughly 13 and 807-fold less than with cigarette smoke.
Sources: en.wikipedia.org
Rodent studies reported increased endurance and fat oxidation after GW501516 exposure. Long-term studies also found higher rates of some tumors, which led to halted development.
Small short-term human trials examined metabolic markers such as lipids and glucose. The trials did not continue after rodent cancer findings, so long-term human safety is unknown.
Controlled human trials have not established a performance benefit. Anecdotal reports exist, but they are not reliable evidence.
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.