This is a working overview of fatty acid oxidation, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-10-14 and is reviewed periodically as new material appears.
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.
Anti-doping laboratories identify GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the usual matrix, and detection can occur after the parent compound has cleared from blood. The exact detection window depends on dose, formulation, individual metabolism, and assay sensitivity. Because the compound is prohibited at all times, athletes are subject to testing in and out of competition. Analytical methods continue to improve as new metabolites and designer analogs are characterized.
GW501516 acts as a ligand for PPAR delta, a nuclear receptor that regulates transcription of genes involved in fatty acid oxidation and energy use. Activation of this receptor in skeletal muscle shifts metabolism toward fat burning in animal models. The compound does not burn fat directly; it changes gene expression over hours to days. Researchers study it to understand metabolic flexibility and exercise adaptation. Effects observed in rodents are not automatically expected in humans.
Preclinical research reported that GW501516 increased running endurance in mice and improved lipid profiles in some animal species. Early human trials explored effects on high-density lipoprotein cholesterol, triglycerides, and glucose handling, but the program was discontinued. Published human data are sparse and do not establish efficacy for any condition. Studies also examined PPAR delta in cancer biology, with conflicting findings across models. The relationship between receptor activation, tissue context, and disease risk remains an active area of investigation.
| 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 |
A common misconception is that cardarine has been proven safe for human use. In reality, human clinical data are limited, and long-term animal studies have raised concerns about cancer. Another misconception is that it is a supplement or vitamin-like compound. It is a synthetic research chemical with no approved medical indication. Scientific discussion often focuses on its mechanism and detection rather than therapeutic use. Regulatory and anti-doping literature treats it primarily as a prohibited substance.
Cardarine is explicitly prohibited by the World Anti-Doping Agency under the class of PPARδ agonists. Its presence in urine or blood samples can be detected using mass spectrometry-based methods, often liquid chromatography-tandem mass spectrometry. Athletes who test positive may face sanctions, including bans from competition. The compound is also regulated as a prescription-only or unapproved drug in many countries. Enforcement varies by jurisdiction, and some regions treat it as a controlled substance. Online sales may occur despite these restrictions, creating quality and legal risks.
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.
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.
==== Blood stains ==== There are several reddish stains on the shroud suggesting blood. McCrone (see painting hypothesis) showed that these contain iron oxide, and theorized that its presence was likely due to simple pigment materials used in medieval times. While the forensic doctor Pierluigi Baima Bollone initially claimed in 1983 to have identified type AB human blood along with traces of serum, aloes, and myrrh, this conclusion was later challenged by researchers like Alan Adler and more recently Kelly Kearse, who noted that early testing methods could not definitively confirm ancient human blood due to degradation and potential contamination. Skeptics cite forensic blood tests whose results dispute the authenticity of the Shroud, and point to the possibility that the blood could belong to a person who handled the shroud, and that the apparent blood flows on the shroud are unrealistically neat. As of 2025, it has not been scientifically demonstrated that the blood is of human, or even primate, origin.
Many such scenarios have been depicted in popular culture, such as in the 1959 film On the Beach, the 1962 novel Fail-Safe, the 1964 film Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb, the 1983 film WarGames, and the 1984 film Threads.
=== Alternative medicine === An experimental treatment, enzyme potentiated desensitization (EPD), has been tried for decades but is not generally accepted as effective. EPD uses dilutions of allergen and an enzyme, beta-glucuronidase, to which T-regulatory lymphocytes are supposed to respond by favoring desensitization, or down-regulation, rather than sensitization. EPD has also been tried for the treatment of autoimmune diseases, but evidence does not show effectiveness. A review found no effectiveness of homeopathic treatments and no difference compared with placebo. The authors concluded that, based on rigorous clinical trials of all types of homeopathy for childhood and adolescent ailments, there is no convincing evidence that supports the use of homeopathic treatments. According to the National Center for Complementary and Integrative Health, US, the evidence is relatively strong that saline nasal irrigation and butterbur are effective, when compared to other alternative medicine treatments, for which the scientific evidence is weak, negative, or nonexistent, such as honey, acupuncture, omega 3's, probiotics, astragalus, capsaicin, grape seed extract, Pycnogenol, quercetin, spirulina, stinging nettle, tinospora, or guduchi.
5-HTP is decarboxylated to serotonin (5-hydroxytryptamine or 5-HT) by the enzyme aromatic-L-amino-acid decarboxylase with the help of vitamin B6. This reaction occurs both in nervous tissue and in the liver. 5-HTP crosses the blood–brain barrier, while 5-HT does not. Excess 5-HTP, especially when administered with vitamin B6, is thought to be metabolized and excreted. Though 5-HTP is found in food only in insignificant quantities, it is a chemical involved intermediately in the metabolism of tryptophan, an amino acid found in all unfractionated foods, with lower total amino acid content correlating with increased tryptophan absorption.
Potassium-40 is especially important in potassium–argon (K–Ar) dating. Argon is a gas that does not ordinarily combine with other elements. So, when a mineral forms – whether from molten rock, or from substances dissolved in water – it will be initially argon-free, even if there is some argon in the liquid. However, if the mineral contains traces of potassium, then decay of the 40K isotope present will create fresh argon-40 that will remain locked up in the mineral. Since the rate at which this conversion occurs is known, it is possible to determine the elapsed time since the mineral formed by measuring the ratio of 40K and 40Ar atoms contained in it. The argon in Earth's atmosphere is 99.6% 40Ar, but the argon in the Sun – and presumably in the primordial material that condensed into the planets – is mostly 36Ar, with less than 15% of 38Ar. It follows that most of Earth's argon derives from potassium-40 that decayed into argon-40, which eventually escaped to the atmosphere.
Sources: en.wikipedia.org
In probability theory, λ represents the density of occurrences within a time interval, as modelled by the Poisson distribution. In mathematical logic and computer science, λ is used to introduce anonymous functions expressed with the concepts of lambda calculus. λ indicates an eigenvalue in the mathematics of linear algebra. In the physics of particles, lambda indicates the thermal de Broglie wavelength In the physics of electric fields, lambda sometimes indicates the linear charge density of a uniform line of electric charge (measured in coulombs per meter). Lambda denotes a Lagrange multiplier in multi-dimensional calculus. In solid-state electronics, lambda indicates the channel length modulation parameter of a MOSFET. In ecology, lambda denotes the long-term intrinsic growth rate of a population. This value is often calculated as the dominant eigenvalue of the age/size class matrix. In formal language theory and in computer science, lambda denotes the empty string. Lambda is a nonstandard symbol in the International Phonetic Alphabet for the voiced alveolar lateral affricate [dɮ]. Lambda denotes the Lebesgue measure in mathematical set theory. The Goodman and Kruskal's lambda in statistics indicates the proportional reduction in error when one variable's values are used to predict the values of another variable. Lambda denotes the oxygen sensor in a vehicle that measures the air-to-fuel ratio in the exhaust gases of an internal-combustion engine. A Lambda 4S solid-fuel rocket was used to launch Japan's first orbital satellite in 1970.
In order to determine the composition of the East German representatives in the Bundestag between German reunification and the first post-reunification elections in December 1990, the results of the 1990 Volkskammer election were recounted, using the new states of Germany as constituencies. This was possible since the original election results were declared on the Kreis level, and the states were re-established by simply amalgamating Kreise together. The results in each Kreis forming a state were summed up to determine the statewide result. The recount fixed the number of Volkskammer members from each party who would be co-opted into the Bundestag.
=== Conductive ink === In 2012 Vorbeck Materials started shipping the Siren anti-theft packaging device, which uses their graphene-based Vor-Ink circuitry to replace the metal antenna and external wiring to an RFID chip. This was the world's first commercially available product based on graphene.
Amyloid fibrils are generally composed of 1–8 protofilaments (one protofilament also corresponding to a fibril is shown in the figure), each 2–7 nm in diameter, that interact laterally as flat ribbons that maintain the height of 2–7 nm (that of a single protofilament) and are up to 30 nm wide; more often protofilaments twist around each other to form the typically 7–13 nm wide fibrils. Each protofilament possesses the typical cross-β structure and may be formed by 1–6 β-sheets (six are shown in the figure) stacked on each other. Each individual protein molecule can contribute one to several β-strands in each protofilament and the strands can be arranged in antiparallel β-sheets, but more often in parallel β-sheets. Only a fraction of the polypeptide chain is in a β-strand conformation in the fibrils, the remainder forms structured or unstructured loops or tails. For a long time our knowledge of the atomic-level structure of amyloid fibrils was limited by the fact that they are unsuitable for the most traditional methods for studying protein structures. Recent years have seen progress in experimental methods, including solid-state NMR spectroscopy and cryo-electron microscopy. Combined, these methods have provided 3D atomic structures of amyloid fibrils formed by amyloid β peptides, α-synuclein, tau, and the FUS protein, associated with various neurodegenerative diseases.
No candidate from PEJUANG or Gerakan Tanah Air secured a seat. He later said that his party's plans "had to be dropped" and he would shift his focus to writing about Malaysian history. In February 2023, Mahathir and 13 other members of PEJUANG (leaving his own son as the sole leader of that party) left the party and joined Parti Bumiputera Perkasa Malaysia (Putra). Later in 2023, Mahathir began promoting a "Malay Proclamation", aimed at uniting Malays. He met with PAS and PN leaders to garner support for the 12-point document listing political, economic and social issues. Mahathir was questioned by police over this campaign under the Malaysian Penal Code, for carrying out "activities that undermine parliamentary democracy". Mahathir also left GTA, criticising the coalition for its poor performance in the election. He supported Perikatan Nasional, the coalition that had ousted him in 2020, in six state elections and was named its "unofficial adviser" for the four state governments under its control. On 31 August 2024, Mahathir attended the Merdeka Day celebration in Putrajaya in his personal capacity, as he was not officially invited by the government. His presence at the event, where he was warmly received by the crowd, sparked public debate. Prominent academic Chandra Muzaffar criticised the government's decision, describing it as a breach of Malaysian etiquette and values, particularly given Mahathir's status as the country's longest-serving prime minister.
Sources: en.wikipedia.org
==== Cytotoxicity inhibition ==== One way that honokiol acts as a neuroprotective is through cellular regulation and subsequent inhibition of cytotoxicity. Two mechanisms used to achieve this inhibition are GABAA Modulation and Ca2+ Inhibition. Cytotoxicity inhibition may be the neuroprotective mechanism of honokiol. Honokiol has also been shown to inhibit repetitive firing by blocking glutamate.
=== Valve Corporation v. Vivendi Universal Games === Between 2002 and 2005, Valve was involved in a complex legal dispute with its publisher, Vivendi Universal Games (under Vivendi's brand Sierra Entertainment). Valve had entered into a publishing agreement with Sierra to release Half-Life and subsequent games in 1997, with the contract giving Sierra some intellectual property (IP) rights to Valve's games. After Valve began development of Half-Life 2, it agreed a new contract with Sierra in 2001, removing these rights from Sierra and giving Valve some rights for digital distribution. Internally, Valve started work on Steam as a means to digitally distribute these games, and first revealed this project at the March 2002 Game Developers Conference. By August 2002, Valve had found that Sierra was distributing copies of their games to Internet cafes against the terms of their contracts and filed a lawsuit against Sierra and Vivendi. In addition to claims of copyright infringement, Valve asserted that Sierra breached contract by withholding royalties and delaying the release of Counter-Strike: Condition Zero until after the holiday season. Vivendi and Sierra countersued, stating that Valve had misrepresented their position in the revised 2001 contract since they had been working on Steam at that point as a means to circumvent the publishing agreement. Vivendi sought intellectual property rights to Half-Life and a ruling preventing Valve from using Steam to distribute Half-Life 2. The countersuits, if successful, likely would have bankrupted Valve, according to COO Scott Lynch.
== Roles in disease and medicine == It has been found to have anticarcinogenic properties. In a study on mice, injecting a preparation of DSIP over the mice's lifetime decreased total spontaneous tumor incidence 2.6-fold. The same study found it to also have geroprotective effects: it slowed down the age-related switching-off of oestrous function; it decreased by 22.6% the frequency of chromosome aberrations in bone marrow cells and it increased by 24.1% maximum life span in comparison with the control group. Levels of DSIP may be significant in patients diagnosed with major depressive disorder (MDD). In several studies, levels of DSIP in the plasma and cerebrospinal fluid are significantly deviated from the norm in patients with MDD, though there are contradictions as to whether levels are higher or lower than healthy control patients. Studies have demonstrated a direct link between GILZ expression (homologous to DSIP) and adipogenesis which has links to obesity and metabolic syndrome. In studies on rats with metaphit-induced epilepsy DSIP acted as an anticonvulsant, significantly decreasing the incidence and duration of fits suggesting DSIP as a potential treatment for epilepsy. DSIP has been found to have an analgesic effect. In studies on mice it was found to have a potent antinociceptive effect when administered intracerebroventricularly or intracisternally (see: Route of administration). Due to its possible effects on sleep and nociception, trials have been carried out to determine whether DSIP can be used as an anaesthetic.
=== Japanese === That night, Toyoda ordered Ozawa to withdraw from the Philippine Sea. U.S. forces gave chase, but the battle was over. The four Japanese air strikes involved 373 carrier aircraft, of which 243 were lost and 130 returned to the carriers; many of them were subsequently lost when Taiho and Shōkaku were sunk. After the second day of the battle, losses totaled three carriers, more than 350 carrier aircraft, and around 200 land-based aircraft. In the five major "carrier-on-carrier" battles, from the Battle of the Coral Sea to the Battle of the Philippine Sea, the IJN had lost nine carriers, while the USN had lost three. The aircraft and trained pilots lost at Philippine Sea were an irreplaceable blow to the already outnumbered Japanese fleet air arm. The Japanese had spent the better part of a year (following the Battle of the Santa Cruz Islands) reconstituting their depleted carrier air groups, and the American Fast Carrier Task Force had destroyed 90% of it in two days. The Japanese had only enough pilots left to form the air group for one of their light carriers. As a consequence, during the Battle of Leyte Gulf four months later, they sent out a decoy carrier group with only 108 aircraft, across four carriers, that was sacrificed in an attempt to draw the American fleet away from protecting the troops and supplies being landed for the Battle of Leyte. The Japanese military, which had hidden the extent of their previous losses from the Japanese public, continued this policy.
=== Stocking === Research from the late 1800s to the 1980s suggests a trend of intentional stockings of nonindigenous fish into ponds, lakes, and rivers in the United States. At that time, little was known about environmental impacts or long-term effects of new species establishment and spread as a result of "fish rescue and transfer" efforts, or the importance of nongame fish to the ecological balance of aquatic ecosystems. Introductions of bowfin to areas they were considered a nonindigenous species included various lakes, rivers, and drainages in Connecticut, Delaware, Georgia, Illinois, Iowa, Kansas, Kentucky, Maryland, Massachusetts, Minnesota, Missouri, New Jersey, New York, North Carolina, Ohio, Oklahoma, Pennsylvania, Virginia, West Virginia, and Wisconsin. Many of the introductions were intentional stockings, positively determining distribution resulting from flood transfers, or other inadvertent migrations is not possible. Bowfin are typically piscivorous, but as an introduced species, they are capable of being voracious predators that pose a threat to native fish and their prey.
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.
It binds to and activates PPAR delta, a nuclear receptor that controls expression of genes related to fatty acid oxidation. This mechanism can alter energy metabolism in animal models. It is not a direct stimulant or fat-burning enzyme.