mass spectrometry 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 2026-02-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
Quality varies among research-grade suppliers, so certificates of analysis and independent testing are important for verification. A typical certificate reports purity by HPLC, identity by mass spectrometry, appearance, and sometimes residual solvents or water content. AOD9604 is often sold as a research chemical not intended for human consumption, and labels can be inaccurate. Common misconceptions include treating the peptide as a form of growth hormone, assuming supplement status, or expecting approved-drug quality from unregulated products.
AOD9604 is commonly supplied as a white to off-white lyophilized powder. The powder is typically stored at -20 °C or below, protected from light and moisture, because peptides can degrade through oxidation, hydrolysis, or aggregation. If it is reconstituted for laboratory use, an appropriate aqueous buffer or solvent is chosen, and the solution is kept cold and handled to avoid repeated freeze-thaw cycles. These practices support stability but do not imply suitability for human use.
Regulatory interest in AOD-9604 increased after high-profile anti-doping cases involving peptide products. In some cases, the substance was supplied under alternative names or in compounded preparations, complicating traceability. Sports tribunals and anti-doping panels have discussed whether the peptide was explicitly banned at the time of use, leading to clarifications by the World Anti-Doping Agency. For consumers and researchers, the legal status can vary by jurisdiction, and products marketed as research chemicals may lack independent quality verification.
AOD-9604 is listed as a prohibited substance in sport by the World Anti-Doping Agency. It falls under the peptide hormones, growth factors, related substances, and mimetics class on the prohibited list. Anti-doping organizations treat its presence in an athlete's sample as an adverse finding unless a therapeutic use exemption applies. The prohibition reflects concerns about performance enhancement in competitive settings and the difficulty of distinguishing exogenous peptide use from endogenous hormone fragments.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized form; visual inspection |
| Solubility | Soluble in water and aqueous buffers | Depends on pH, purity, and counterion |
| Typical storage | -20 °C or below, desiccated | Protect from light; avoid repeated freeze-thaw after reconstitution |
| Common analytical method | Reversed-phase HPLC and mass spectrometry | Purity by HPLC; identity and mass by LC-MS or MALDI-TOF |
| Common synonyms | hGH fragment 176–191; AOD-9604 | Names vary in research and product labeling |
Regulatory treatment of AOD-9604 has varied. In sports anti-doping, the peptide became widely discussed during a 2013 investigation into an Australian professional sports club. Authorities at the time debated whether it fell under prohibitions on growth hormone and related substances. Later clarifications and updated lists have addressed the compound in different ways. Anyone seeking current status should consult the latest applicable rules, and commercial supply for human use is not authorized in major markets.
Research interest in AOD-9604 often focuses on whether it can influence lipid metabolism without the growth-promoting or glucose-related effects of full-length hGH. This question remains unresolved, and findings depend on model, dose, and measurement method. Some reviews treat the peptide as a historical obesity candidate rather than an active therapeutic. Others cite it in discussions of peptide fragments, metabolic signaling, and performance-enhancing substances. Clear conclusions are limited by the small number of rigorous, independent human studies.
AOD-9604 has been investigated primarily as a potential treatment for obesity and related metabolic conditions. Early laboratory work examined its effects on fat cells, and later studies moved into animal models and human clinical trials. Some trials reportedly reached Phase II, but the program did not lead to an approved medicine. Published summaries often note that weight-loss results were modest or inconsistent. The full trial data are not all publicly available in detail.
Quality control for AOD-9604 involves verifying identity, purity, and concentration. Suppliers may provide a certificate of analysis listing HPLC purity and mass spectrometry data. Independent verification is advised because peptide products can vary in quality. Researchers should check for counterions, residual solvents, and microbial contamination. Proper documentation supports reproducibility and safety in laboratory studies. When sourcing, institutions often require third-party testing and detailed chain-of-custody records. These steps help ensure that experimental results are attributable to the peptide rather than impurities.
Analytical characterization of AOD-9604 typically employs reversed-phase high-performance liquid chromatography (RP-HPLC) to assess purity and identity. Mass spectrometry provides confirmation of molecular mass, while amino acid analysis can verify composition. These methods are standard for peptide research chemicals. Because the peptide lacks a distinct chromophore, detection often relies on ultraviolet absorbance at 214 nm or mass spectrometric response. Laboratories may also use capillary electrophoresis for separation. For example, size-exclusion chromatography can detect aggregates.
Regulatory treatment of AOD-9604 is shaped by its classification as a peptide hormone. The World Anti-Doping Agency lists it as a prohibited substance, and many national anti-doping organizations adopt that list. It does not hold approval as a prescription medicine in the United States, the European Union, or other major markets. Products sold online are frequently labeled for research use only and may not undergo independent quality testing. Import and possession rules differ by country, so legal status depends on local law.
Proposed mechanisms for AOD-9604 focus on fat cells. Laboratory studies suggest the peptide can increase lipolysis, the breakdown of stored fat, and reduce lipogenesis, the formation of new fat. Unlike full human growth hormone, it does not appear to stimulate substantial IGF-1 production in the studies reported so far. Some evidence points to beta-adrenergic signaling, but the precise receptor targets and downstream pathways remain unresolved. The fragment is not thought to act through the classical growth hormone receptor.
A central uncertainty is whether observed metabolic changes translate into meaningful clinical benefits. Study designs vary in dose, duration, and participant characteristics, making comparisons difficult. Independent replication is limited, and the field lacks consensus on optimal endpoints or treatment duration. Ongoing or future studies may clarify mechanism and effect size, but current evidence does not establish a clear therapeutic role. Researchers often call for larger, longer, and better-controlled trials, while questions remain about which patient groups might respond.
Proposed mechanism focuses on lipolysis, the breakdown of stored triglycerides into free fatty acids and glycerol. AOD-9604 is thought to act on adipose tissue without stimulating appetite or affecting blood sugar in the same way as growth hormone. Laboratory studies report increased fat oxidation in some models. The precise receptor interactions and signaling pathways remain incompletely characterized. Researchers have proposed that the peptide may influence fat mobilization through pathways distinct from the full hormone.
Research has examined whether the peptide affects fat mass independently of growth hormone's other actions. Early animal studies suggested reductions in body fat, but species differences and small sample sizes limit interpretation. Human studies have generally been short and have not consistently shown large effects. Some trials measured body composition, lipid profiles, and safety parameters, but the overall picture is one of suggestive yet inconclusive metabolic activity. Findings vary across study populations and protocols.
=== Functional Genomics === This program studies genes involved in physiological systems and their pharmaceutical applications. It characterizes gene functions and interactions using rodent models at the Czech Centre for Phenogenomics, which is part of the Infrafrontier consortium. Research includes liver function, cardiovascular dysfunction, diabetes, metabolic disorders, hearing loss, and ocular disease.
S: The number of susceptible individuals. When a susceptible and an infectious individual come into "infectious contact", the susceptible individual contracts the disease and transitions to the infectious compartment. I: The number of infectious individuals. These are individuals who have been infected and are capable of infecting susceptible individuals. R for the number of removed (and immune) or deceased individuals. These are individuals who have been infected and have either recovered from the disease and entered the removed compartment, or died. It is assumed that the number of deaths is negligible with respect to the total population. This compartment may also be called "recovered" or "resistant". This model is reasonably predictive for infectious diseases that are transmitted from human to human, and where recovery confers lasting resistance, such as measles, mumps, and rubella.
In 2004, a special issue of The International Journal of Sociology and Social Policy was published that was edited by Steven P. Schacht, who participated in the SSSP session. The special issue contained ten articles analyzing his research and his multiple contributions as a social activist and scholar. The authors of these articles call for sociologists and others to move beyond criticism of Humphrey's research methodologies in the tearoom study, and instead to focus on his pioneering contributions to the study of sexuality, participant-observation as method, development of sociological theory, and his work as a social activist and advocate for marginalized sexual identities.
After the Fermi publication, Otto Hahn, Lise Meitner, and Fritz Strassmann began performing similar experiments in Berlin. Meitner, an Austrian Jew, lost her Austrian citizenship with the Anschluss, the union of Austria with Germany in March 1938, but she fled in July 1938 to Sweden and started a correspondence by mail with Hahn in Berlin. By coincidence, her nephew Otto Robert Frisch, also a refugee, was also in Sweden when Meitner received a letter from Hahn dated 19 December describing his chemical proof that some of the product of the bombardment of uranium with neutrons was barium. Hahn suggested a bursting of the nucleus, but he was unsure of what the physical basis for the results were. Barium had an atomic mass 40% less than uranium, and no previously known methods of radioactive decay could account for such a large difference in the mass of the nucleus. Frisch was skeptical, but Meitner trusted Hahn's ability as a chemist. Marie Curie had been separating barium from radium for many years, and the techniques were well known. Meitner and Frisch then correctly interpreted Hahn's results to mean that the nucleus of uranium had split roughly in half. Frisch suggested the process be named "nuclear fission", by analogy to the process of living cell division into two cells, which was then called binary fission. Just as the term nuclear "chain reaction" would later be borrowed from chemistry, so the term "fission" was borrowed from biology.
==== Monoamine oxidase B (MAO-B) inhibitors ==== Rasagiline (Agilect; AGN-1135; Azilect; Elbrus; Lu-00-773; TV-1030; TVP-101; TVP-1012) – monoamine oxidase B (MAO-B) inhibitor [338] Safinamide (EMD-1195686; Equfina; FCE-26743; ME-2125; NW-1015; Onstryv; PNU-151774; Xadago; ZP-034) – reversible monoamine oxidase B (MAO-B) inhibitor and other actions [339] Selegiline (Eldepryl, Jumex) – monoamine oxidase B (MAO-B) inhibitor and other actions Selegiline orally disintegrating tablet (Efupi; FPF-1100-NW; selegiline ODT) – monoamine oxidase B (MAO-B) inhibitor and other actions [340]
Sources: en.wikipedia.org
Proamylin, which is cosecreted with proinsulin, requires the above three factors and an amidating monooxygenase to convert itself to an active hormone. Some pro-protein precursors, such as preproinsulin, also go through this process, with the added step of removing a signal peptide by signal peptidases, to convert said precursors into prohormones.
Besides the core data on panning experiments and their results, broad background information on target, template, library and structure is included. An accompanied benchmark has also been compiled for bioinformaticians to develop and evaluate their new models, algorithms and programs. In addition, the MimoDB database provides tools for simple and advanced searches, structure visualization, BLAST and alignment view on the fly. The experimental biologists can easily use the database as a virtual control to exclude possible target-unrelated peptides. The MimoDB database is freely available.
Classical (or "Werner Complexes"): Ligands in classical coordination chemistry bind to metals, almost exclusively, via their lone pairs of electrons residing on the main-group atoms of the ligand. Typical ligands are H2O, NH3, Cl−, CN−, en. Some of the simplest members of such complexes are described in metal aquo complexes, metal ammine complexes, Examples: [Co(edta)]−, [Co(NH3)6]3+, [Fe(C2O4)3]3− Organometallic chemistry: Ligands are organic (alkenes, alkynes, alkyls) as well as "organic-like" ligands such as phosphines, hydride, and CO. Example: (C5H5)Fe(CO)2CH3 Bioinorganic chemistry: Ligands are those provided by nature, especially including the side chains of amino acids, and many cofactors such as porphyrins. Example: hemoglobin contains heme, a porphyrin complex of iron Example: chlorophyll contains a porphyrin complex of magnesium Many natural ligands are "classical" especially including water. Cluster chemistry: Ligands include all of the above as well as other metal ions or atoms as well. Example Ru3(CO)12 In some cases there are combinations of different fields: Example: [Fe4S4[S(cysteinyl)]4]2−, in which a cluster is embedded in a biologically active species. Mineralogy, materials science, and solid state chemistry – as they apply to metal ions – are subsets of coordination chemistry in the sense that the metals are surrounded by ligands. In many cases these ligands are oxides or sulfides, but the metals are coordinated nonetheless, and the principles and guidelines discussed below apply. In hydrates, at least some of the ligands are water molecules.
In a complementary technique, peptide mass fingerprinting involves digestion of the native and modified protein with a protease such as trypsin. This will produce a set of peptides that can be analysed using a mass spectrometer. The peptide that changes in mass after reaction with the inhibitor will be the one that contains the site of modification.
Sources: en.wikipedia.org
Lyophilized AOD9604 is generally kept at -20 °C or colder, desiccated, and protected from light. Reconstituted solutions are usually refrigerated and handled to minimize repeated freeze-thaw cycles. These are general laboratory handling practices, not instructions for human use.
Mass spectrometry, such as LC-MS or MALDI-TOF, confirms the molecular mass and can reveal sequence-related impurities. Reversed-phase HPLC is used for purity, and peptide mapping or amino acid analysis can support sequence identity. No single method establishes every quality attribute.
No. AOD9604 is a short synthetic fragment of the hGH sequence, not the full 191-amino-acid hormone. It lacks the regions that mediate hGH receptor activation and growth-promoting effects. Products labeled as AOD9604 should not be assumed to have the same properties as hGH.
Yes, the World Anti-Doping Agency classifies AOD-9604 as a prohibited peptide hormone and related substance. Its use by athletes is banned under the relevant anti-doping code.