A practical reference on Investigational drug: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-03-27 and is reviewed periodically as new material appears.
GW501516 acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in transcription of genes related to lipid handling and energy use. Activation of PPARδ can shift skeletal muscle toward greater fatty acid oxidation in animal models, which is one reason it drew interest for metabolic disease and exercise research. The exact downstream effects depend on tissue, species, dose, and duration. Human data are sparse, so many proposed benefits remain hypotheses rather than established clinical outcomes.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Solubility | Soluble in dimethyl sulfoxide and some organic solvents; practically insoluble in water | Solvent choice affects laboratory handling |
| Typical storage | -20 °C, desiccated, protected from light | Common condition for research samples |
| Analytical method | Liquid chromatography–tandem mass spectrometry (LC-MS/MS) | Used for identification and quantification in biological or product samples |
| Common synonyms | GW501516, GW-501516, GSK-516, Endurobol | Names found in research and anti-doping literature |
| Regulatory status | Unapproved therapeutic; prohibited in competitive sport | Status can vary by country and context |
Cardarine is a common name for GW501516, an investigational compound developed in the 1990s for metabolic conditions. It acts as an agonist at peroxisome proliferator-activated receptor delta, a nuclear receptor involved in lipid and energy metabolism. The compound is frequently mislabeled as a selective androgen receptor modulator, or SARM, but its molecular target is different. GW501516 reached early clinical testing before development was discontinued. It has no approved therapeutic use in any country. The name cardarine is not a formal international nonproprietary name.
Regulatory treatment varies, but cardarine is not approved as a medicine. Sports authorities list GW501516 as a prohibited substance, and it is banned at all times under the World Anti-Doping Agency code. Many countries restrict sales for human consumption, while online vendors market it as a research chemical. Such products may lack purity data, and their actual contents can differ from the label. Purchasing or possessing cardarine may carry legal consequences depending on jurisdiction. The compound is not a dietary supplement ingredient in regulated markets.
Clinical development stopped after rodent studies showed tumors at multiple sites. Whether those findings predict human cancer risk remains an open question, but they led sponsors to discontinue programs. Human safety data are limited to small, short-term studies that were not designed to assess cancer risk. Reported effects in those studies included changes in blood lipids, but the evidence is insufficient for medical use. Long-term consequences of nonmedical use are not well characterized. Questions about dose, duration, and individual susceptibility remain unresolved.
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.
Laboratory detection of cardarine typically involves sample preparation followed by chromatographic separation and mass spectrometric identification. Urine is the most common matrix for anti-doping tests, though blood and hair have also been explored. Methods can target the parent compound or its metabolites, depending on the expected window of detection. Reference standards are required for accurate quantification. Matrix effects and dilution can influence results, so laboratories use internal standards and validation protocols. The exact detection window varies with dose, route, and individual metabolism.
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.
Soon after the Big Bang, roughly 14 Gya (14 billion years ago), the only chemical elements present in the universe were hydrogen, helium, and lithium, the three lightest atoms in the periodic table. These elements gradually condensed into vast clouds of gas, which collapsed under gravity into rotating protostellar disks. Gravitational accretion of material at the hot and dense centers of these disks formed the first stars by the fusion of hydrogen. Early stars were massive and short-lived, producing all the heavier elements by stellar nucleosynthesis. Such element formation proceeds to its most stable element Iron-56. Heavier elements were formed during supernovas at the end of a star's lifecycle. Carbon, currently the fourth most abundant element in the universe, was formed mainly in white dwarf stars. As these stars reached the end of their lifecycles, they ejected heavier elements, including carbon and oxygen, throughout the universe. These allowed for the formation of rocky planets. According to the nebular hypothesis, the Solar System began to form 4.6 Gya with the gravitational collapse of part of a giant molecular cloud. Most of the collapsing mass collected in the center, forming the Sun, while the rest flattened into a protoplanetary disk out of which the planets formed.
Both the thyroid and adrenal glands can be infiltrated. It is estimated that 10–20% of people with amyloidosis have hypothyroidism. Adrenal infiltration may be harder to appreciate given that its symptoms of orthostatic hypotension and low blood sodium concentration may be attributed to autonomic neuropathy and heart failure. "Amyloid deposits occur in the pancreas of people who also have diabetes mellitus, although it is not known if this is functionally important. The major component of pancreatic amyloid is a 37-amino acid residue peptide known as islet amyloid polypeptide or 'amylin.' This is stored with insulin in secretory granules in [beta] cells and is co secreted with insulin." (Rang and Dale's Pharmacology, 2015.)
Cytochrome-b5 reductase is a NADH-dependent enzyme that converts ferricytochrome from a Fe3+ form to a Fe2+ form. It contains FAD and catalyzes the reaction: In its b5-reducing capacity, this enzyme is involved in desaturation and elongation of fatty acids, cholesterol biosynthesis, and drug metabolism. This enzyme can also reduce methemoglobin to normal hemoglobin, gaining it the inaccurate synonym methemoglobin reductase. Isoforms expressed in erythrocytes (CYB5R1, CYB5R3) perform this function in vivo. Ferricyanide is another substrate in vitro.
Lactation suppression Hyperprolactinemia Adjunctive therapy of prolactin-producing pituitary gland tumors (prolactinomas); Monotherapy of Parkinson's disease in the early phase; Combination therapy, together with levodopa and a decarboxylase inhibitor such as carbidopa, in progressive-phase Parkinson's disease; In some countries also: ablactation and dysfunctions associated with hyperprolactinemia (amenorrhea, oligomenorrhea, anovulation, nonpuerperal mastitis and galactorrhea); Treatment of uterine fibroids. Adjunctive therapy of acromegaly: Cabergoline has low efficacy in suppressing growth hormone levels and is highly efficient in suppressing hyperprolactinemia, which is present in 20–30% of acromegaly cases. Growth hormone and prolactin are similar structurally and have similar effects in many target tissues; therefore, targeting prolactin may help symptoms when growth hormone secretion cannot be sufficiently controlled by other methods. Cabergoline is frequently used as a first-line agent in the management of prolactinomas due to its higher affinity for D2 receptor sites, less severe side effects, and more convenient dosing schedule than the older bromocriptine, though in pregnancy bromocriptine is often still chosen since there is less data on safety in pregnancy for cabergoline.
Sources: en.wikipedia.org
From 2011, new cars should have brake assist system in the EU, according to The Pedestrian Protection Regulation (EC) 78/2009. Starting in 2012, all cars under 10,000 lbs. sold in the US are required to have Electronic Stability Control. In 2014, ESP (Electronic Stability Program) and TPMS became mandatory in the European Union, with also the driver seat belt reminder and the ISOFIX system, under General Safety Regulation (EC) No 661/2009. In 2015, recognizing that safer roads are a shared responsibility, Together for Safer Roads (TSR) was formally launched to align the private sector's road safety efforts with the United Nations Decade of Action for Road Safety. In 2016 and 2017, ABS became mandatory on motorcycles in the EU. In 2018, eCall became mandatory in the EU, and reverse camera in the US. In 2019, the EU legislated to revise the General Safety Regulation (GSR), the revision includes the following automotive safety features:
5-HTP has been used medically and as a supplement under the name oxitriptan in the treatment of depression and for certain other indications. As of 2025, there are no current FDA approved medications containing 5-HTP. It can be potentiated in combination with a peripherally selective aromatic L-amino acid decarboxylase (AAAD) inhibitor such as carbidopa or benserazide. These agents increase the strength and duration of oxitriptan. An investigational combination formulation is oxitriptan/carbidopa.
In cancer cells, an increase in Akt signaling correlates with an increase in glucose metabolism, compared to normal cells. Cancer cells favour glycolysis for energy production over mitochondrial oxidative phosphorylation, even when oxygen supply is not limited. This is known as the Warburg effect, or aerobic glycolysis. Akt affects glucose metabolism by increasing translocation of glucose transporters GLUT1 and GLUT4 to the plasma membrane, increasing hexokinase expression and phosphorylating GSK3 which stimulates glycogen synthesis. It also activates glycolysis enzymes indirectly, via HIF transcription factors and phosphorylation of phosphofructokinase-2 (PFK2) which activates phosphofructokinase-1 (PFK1). Protein kinase B PI3K/AKT/mTOR pathway Signal transduction KEGG Pathway: PI3K-Akt signaling pathway CST: PI3K/Akt Signaling Resources
Sources: en.wikipedia.org
It binds and activates PPARδ, a nuclear receptor that influences gene expression related to fatty acid metabolism and energy balance. This mechanism has been studied mainly in animals and cell models, not established as a safe human therapy.
No. It is not an anabolic-androgenic steroid; it is a synthetic PPARδ agonist. Because it is banned in sport, it is sometimes grouped with doping agents even though its chemical class differs from steroids.
Human data are limited and development was discontinued, so major effects and long-term risks are not well characterized. Some early studies examined metabolic markers, but they do not provide a basis for unsupervised use.
Cardarine targets PPARδ, a nuclear receptor involved in lipid and energy metabolism. It does not bind the androgen receptor in the way SARMs do.