A practical reference on LC-MS/MS: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-10-11. Anything still debated is marked as such rather than presented as settled.
Cardarine is a common name for GW501516, also GW-1516, a synthetic compound developed as a peroxisome proliferator-activated receptor delta (PPARδ) agonist. It belongs to a class of agents that modulate gene transcription related to lipid and energy metabolism. The compound was studied in preclinical and early clinical research for metabolic and cardiovascular conditions, but it did not progress to approved therapeutic use. Its name appears in fitness and sports contexts despite not being approved as a drug.
PPARδ is a nuclear receptor that influences transcription of genes involved in fatty acid oxidation, lipid transport, and energy homeostasis. GW501516 binds and activates this receptor with high selectivity relative to PPARα and PPARγ in laboratory assays. Activation alters expression of target genes in skeletal muscle, liver, and adipose tissue in animal models. The exact clinical consequences of these changes in humans remain incompletely characterized, and observed effects in animals do not establish therapeutic benefit or safety.
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.
Safety discussions about cardarine frequently cite rodent carcinogenicity findings reported in the 2000s. In those studies, treated animals developed tumors at multiple sites, leading sponsors to discontinue clinical development. The relevance of these findings to humans has not been resolved, but they are a major reason the compound is not approved. Current literature emphasizes uncertainty about long-term effects and the risks of unregulated use. Regulators and health agencies have not established a safe human exposure level.
| Property | Value | Notes |
|---|---|---|
| Chemical class | PPARδ agonist | Not an anabolic steroid. |
| Common synonyms | GW501516, GW-1516 | Cardarine is an informal name. |
| Appearance | White to off-white powder | Typical for research-grade solid. |
| Solubility class | Poorly soluble in water; soluble in some organic solvents | Such as DMSO or ethanol in laboratory settings. |
| Typical storage temperature | Cool, dry, protected from light | Specific conditions vary by supplier and form. |
Cardarine is prohibited in competitive sport under the World Anti-Doping Agency code, where it is classified as a metabolic modulator. It is not approved as a prescription medicine in the United States, European Union, or other major markets. Regulatory action has focused on its presence in sports and in products marketed as research chemicals. Because it has no accepted medical indication, supply is often unregulated. This status creates legal and safety uncertainties for anyone who encounters the substance.
Anti-doping laboratories detect GW501516 and its metabolites using liquid chromatography-tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be used in some programs. Detection depends on factors such as dose, timing, metabolism, and the sensitivity of the assay. Published methods describe limits of detection in the low nanogram per milliliter range for related compounds. Exact detection windows are not fixed for all situations and remain an area of ongoing study.
Anti-doping laboratories identify GW501516 and related metabolites using liquid chromatography coupled with tandem mass spectrometry. Urine is the most common matrix, though blood and dried blood spots may also be analyzed. The method targets the parent compound and phase I and phase II metabolites, which extend the detection window. Because the substance is prohibited at all times, athletes can be tested outside competition. Detection limits and windows depend on the assay, sample type, and individual metabolism.
Cardarine is frequently described as a fat-burning or endurance-enhancing supplement, but these claims exceed the available evidence. The compound is not a hormone, steroid, or selective androgen receptor modulator. Research articles discuss it as a tool compound for studying PPARδ biology, while anti-doping literature focuses on its abuse and detection. Quality of unapproved products is uncertain, and independent analyses have found impurities or incorrect labeling. Open questions include whether human cancer risk resembles that seen in rodents and how often non-athletes use the substance.
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.
==== Sanctions ==== On 15 September, the company issued a public apology for the contaminated powdered milk; Sanlu was ordered to halt production, and to destroy all unsold and recalled products. Authorities reportedly seized 2,176 tons of powdered milk in Sanlu's warehouses. An estimated 9,000 tons of product had been recalled. Tian Wenhua, chairwoman and general manager of Sanlu and Secretary of the Sanlu Communist Party chapter was stripped of her party and functional posts during an extraordinary meeting of the Hebei provincial standing committee of the CCP; four Shijiazhuang officials, including vice mayor in charge of food and agriculture, Zhang Fawang, were reportedly removed from office. Shijiazhuang Mayor Ji Chuntang resigned on 17 September. Li Changjiang, minister in charge of the AQSIQ, was forced to resign on 22 September after the State Council inquest concluded he was responsible for the "negligence in supervision". Investigators also blamed the Shijiazhuang government. Local Party Secretary Wu Xianguo was fired on the same day.
== Areas == In-space manufacturing (ISM) can be categorized into three different areas according to the end use of manufactured products. In-space manufacturing for space (space-for-space) involves activities focused on in-orbit construction intended for use in space. ISM for Earth (space-for-Earth) is the production of new materials and products that exhibit enhanced properties when manufactured in microgravity, subsequently transported back to Earth. Lastly, ISM for surface extends to surface operations on celestial bodies such as the Moon, Mars, and asteroids.
The parties of the Weimar Coalition (Social Democrats, Centre and the left-liberal German Democratic Party (DDP)) were the base of the Weimar Republic but lost their majority in the 1920 elections. After this, majority governments were rare as they required the support of the Weimar Coalition and the national liberal German People's Party (DVP). Social Democrats and DVP found it hard to agree on economic policy while Social Democrats disagreed with the Centre Party on issues like religious schools or a nationwide Concordat with the Holy See. Following the 1920 elections, the Centre's Constantin Fehrenbach formed a minority government in a coalition with the DDP and the DVP. In May 1921 the Weimar Coalition once again joined forces with the Centre's Joseph Wirth as Chancellor, but this minority government collapsed again in November 1922. After this, the Centre participated in the non-affiliated Wilhelm Cuno's "government of the economy", together with both liberal parties and the Bavarian People's Party (BVP). In August 1923, the DVP's Gustav Stresemann formed a Grand Coalition administration, comprising the Centre, both Liberal parties and the Social Democrats, which lasted until November, when the Social Democrats left the coalition and the Centre's Wilhelm Marx became chancellor of a cabinet of the remaining parties. In January 1925 the non-affiliated Hans Luther was appointed chancellor and formed a coalition between the Centre, both Liberal parties, the BVP and, for the first time, the right-wing German National People's Party (DNVP).
Sources: en.wikipedia.org
=== CDK dependent functions === The cyclin D1-CDK4 complex promotes passage through the G1 phase by inhibiting the retinoblastoma protein (pRb). Cyclin D1-CDK4 inhibits pRb through phosphorylation, allowing E2F transcription factors to transcribe genes required for entry into the S phase. Inactive pRb allows cell cycle progression through the G1/S transition and allows for DNA synthesis. Cyclin D1-CDK4 also enables the activation of cyclin E-CDK2 complex by sequestering Cip/Kip family CDK inhibitory proteins p21 and p27, allowing entry into the S phase. Cyclin D1-CDK4 also associates with several transcription factors and transcriptional co-regulators.
=== Behavioral therapy === Paralleling the variety of medical treatments, there are many forms of psychotherapy and community support for treating OUD. The primary evidence-based psychotherapies include cognitive behavioral therapy (CBT), motivational enhancement therapy (MET), contingency management (CM), and twelve-step programs. Community-based support such as support groups (e.g., Narcotics Anonymous) and therapeutic housing for those with OUD is also an important aspect of healing.
Hydroxynorketamine (HNK), or 6-hydroxynorketamine, is a minor metabolite of the anesthetic, dissociative, and antidepressant drug ketamine. It is formed by hydroxylation of the intermediate norketamine, another metabolite of ketamine. As of late 2019, (2R,6R)-HNK is in clinical trials for the treatment of depression. The major metabolite of ketamine is norketamine (80%). Norketamine is secondarily converted into 4-, 5-, and 6-hydroxynorketamines (15%), mainly HNK (6-hydroxynorketamine). Ketamine is also transformed into hydroxyketamine (5%). As such, bioactivated HNK comprises less than 15% of a dose of ketamine.
Sources: en.wikipedia.org
=== Trypsin === Trypsin (EC 3.4.21.4) is a serine protease that cleaves protein substrates after lysine or arginine residues using a catalytic triad to perform covalent catalysis, and an oxyanion hole to stabilise charge-buildup on the transition states.
No more than 5 hydrogen bond donors (the total number of nitrogen–hydrogen and oxygen–hydrogen bonds) No more than 10 hydrogen bond acceptors (all nitrogen or oxygen atoms) A molecular mass less than 500 daltons A calculated octanol-water partition coefficient (Clog P) that does not exceed 5 Note that all numbers are multiples of five, which is the origin of the rule's name. As with many other rules of thumb, such as Baldwin's rules for ring closure, there are many exceptions.
=== Human Warnings === Difloxacin has been approved for animal use only. Keep out of reach of children. Avoid contact with eyes. In case of contact, immediately flush eyes with copious amounts of water for fifteen minutes. In case of dermal contact, wash skin with soap and water. Consult a physician if symptoms persists following exposure. Individuals with a history of hypersensitivity to quinolones should avoid this product. In humans, there is a risk of user photosensitization within a few hours after excessive exposure to quinolones. If excessive accidental exposure occurs, avoid direct sunlight.
Paleodemography studies demographic characteristics of past populations. Bioarchaeologists use paleodemography to create life tables, a type of cohort analysis, to understand demographic characteristics (such as risk of death or sex ratio) of a given age cohort within a population. It is often necessary to estimate the age and sex of individuals based on specific morphological characteristics of the skeleton.
Sources: en.wikipedia.org
Cardarine is commonly known as GW501516 or GW-1516. These names refer to the same synthetic compound. It is not a brand-name approved medicine.
No, cardarine is not a steroid. It is classified as a PPARδ agonist. Its structure and receptor target differ from anabolic steroids.
No regulatory agency has approved cardarine as a medicine. It was investigated in early research but development was discontinued. It is not available as a prescription drug.
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.