A practical reference on synthetic peptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-02-22. Anything still debated is marked as such rather than presented as settled.
Regulatory status: AOD-9604 is not approved as a therapeutic drug in the United States, European Union, or other major markets. It is listed by the World Anti-Doping Agency as a prohibited substance in sport, specifically under growth hormone fragments. Many jurisdictions restrict its sale for human consumption. Products marketed online may not meet pharmaceutical quality standards. The legal status varies by country and often depends on whether the material is presented as a research chemical, supplement, or drug.
Detection and characterization of AOD-9604 in research and anti-doping settings typically rely on mass spectrometry coupled with liquid chromatography. These methods can identify the peptide by its mass and fragmentation pattern. Immunoassays may also be used in some screening contexts, but they can cross-react with related peptides. Because the molecule is small and may be present at low concentrations, sample preparation and method validation are important. Confirmatory analysis usually requires comparison with a certified reference standard.
AOD-9604 is a synthetic peptide modeled on the C-terminal region of human growth hormone. It is often described as hGH fragment 176-191. Research interest arose because it was designed to isolate possible effects on fat metabolism from other actions of growth hormone. It is not a full growth hormone molecule. Its development history includes early laboratory and animal studies followed by human trials. The peptide has been examined in laboratory, animal, and limited human studies.
The compound has been studied as a potential treatment for obesity and related metabolic conditions. Published trials have examined changes in body weight, fat mass, and safety markers over limited durations. Results have been mixed or modest, and no large-scale outcome trials are established. Regulatory agencies in several countries have not approved it as a therapeutic drug. Some commercial products have been marketed outside regulated pharmaceutical channels, which raises questions about quality and claims.
In the scientific literature, AOD-9604 appears in reviews of growth hormone fragments and in discussions of peptide-based metabolic research. Some sources distinguish it from growth hormone itself, while others group it with compounds marketed for weight management. The evidence base is small compared with approved obesity medications. Questions about long-term efficacy and clinical relevance remain open, and independent replication of key findings is limited. Most published reports are early-stage and exploratory.
| Property | Value | Notes |
|---|---|---|
| Regulatory status | Not approved as a medicine | Status varies by country; prohibited in sport. |
| Common storage temperature | 2–8 °C for lyophilized powder | Protect from light and moisture; follow supplier instructions. |
| Typical analytical method | LC-MS/MS | Used for identification and quantification in biological samples. |
| Purity assessment | HPLC and mass spectrometry | Reverse-phase HPLC is common for peptide purity. |
| Common synonyms | AOD9604; hGH 176-191 fragment | Naming conventions differ across studies. |
Several names appear in scientific and commercial settings. AOD9604 and AOD-9604 are development codes used interchangeably, while hGH fragment 176-191 describes the same region. The peptide includes a disulfide bond between two cysteine residues, which helps shape its three-dimensional structure. Different suppliers may provide acetate or other salt forms, and purity can vary. These differences matter because analytical tests and biological assays can respond to the specific form being studied.
Early interest in AOD-9604 centered on whether a fragment of human growth hormone could influence fat metabolism without the broader effects of the full hormone. Cell and animal studies reported changes in fat storage and breakdown. Human trials followed, but the results were not strong enough to secure regulatory approval. The compound remains available for laboratory research, and its clinical potential is still described as uncertain. Studies continue to examine its activity and safety profile.
AOD-9604 is a synthetic peptide whose sequence matches the C-terminal fragment of human growth hormone, specifically residues 176 through 191. This region differs from the full hormone in its receptor interactions. The peptide is not a growth hormone secretagogue and does not bind the growth hormone receptor in the same manner. Researchers have examined it for effects on lipid metabolism, but its exact pharmacological profile remains an active area of study.
Development of AOD-9604 began in the 1990s as scientists sought to isolate metabolic effects of growth hormone without its growth-promoting actions. Early laboratory work focused on fat cells and animal models. Several human trials followed, examining changes in body composition and fat mass. Results have been mixed, and the peptide has not progressed to widespread clinical approval. Interest continues in research settings, particularly regarding its mechanism and potential metabolic targets.
Regulatory status varies by country. In the United States, AOD-9604 is not approved as a prescription drug. It is sometimes sold as a research chemical or dietary supplement, though such marketing may fall outside legal frameworks. The World Anti-Doping Agency prohibits its use in sport. Researchers must obtain it through legitimate suppliers and follow institutional rules. Its legal classification continues to evolve as authorities increasingly assess peptide products more broadly.
The peptide is frequently described as a growth hormone fragment, although it is chemically distinct from full-length hGH. AOD-9604 contains 16 amino acids and includes two cysteine residues that can form an intramolecular disulfide bond. In solution, this structural feature can influence folding, aggregation, and stability. Published descriptions sometimes call it hGH 176-191 or AOD9604, with spacing and capitalization varying. Such naming differences can complicate literature searches, database entries, and product verification.
Researchers have studied the fragment in cell and animal models to understand its metabolic actions. Some experiments report effects on fat breakdown and fat storage pathways, but the underlying mechanism remains incompletely defined. AOD-9604 does not appear to stimulate the same broad growth hormone receptor signaling as full-length hGH. Whether its observed activities arise from direct receptor interactions or downstream metabolic changes is an open question. Results from different assays are not always consistent.
AOD-9604 is a synthetic peptide modeled on the C-terminal region of human growth hormone. It corresponds to residues 176-191 of the 191-amino-acid hGH sequence. The fragment is not the full hormone and lacks the receptor-binding region associated with growth and metabolic effects of hGH. Researchers developed it to isolate a specific portion of hGH for study. Its exact sequence and length are often stated in peptide catalogs and patents.
AOD-9604 has been investigated mainly in the context of body fat and metabolic endpoints. Some early animal and small human studies reported changes in fat mass or lipid markers, but findings were not uniform. Larger, well-controlled trials that would establish efficacy are lacking in the public literature. As a result, claims about weight loss or metabolic benefit remain investigational rather than established. The distinction between a research finding and a proven clinical outcome is central to discussing this peptide.
Regulatory bodies have taken different approaches to AOD-9604. It is not approved as a prescription medicine by major agencies such as the U.S. Food and Drug Administration or the European Medicines Agency. In sport, the World Anti-Doping Agency prohibits peptide hormones, growth factors, and related substances, and AOD-9604 has been treated as a prohibited substance. These regulatory decisions reflect concerns about safety, efficacy, and potential misuse rather than proof of benefit.
Research on AOD-9604 also examines how the peptide is measured in biological samples. Analytical methods may include liquid chromatography coupled with mass spectrometry, immunoassays, or both. Detection can be challenging because the peptide is small and may be present at low concentrations. Published methods vary in sensitivity and specificity, so comparative interpretation requires attention to validation details. The presence of related hGH fragments can complicate identification in some matrices.
== Uses == Oclacitinib is labeled to treat atopic dermatitis and itchiness (pruritus) caused by allergies in dogs, though it has also been used to reduce the itchiness and dermatitis caused by flea infestations. While some say it is best only for acute flares of itchiness, others claim that it is also useful in chronic atopic dermatitis. It is considered to be highly effective in dogs and has been established as safe for at least short-term use. Its efficacy is comparable to prednisolone early in treatment, and although oclacitinib has been shown to be more effective in the short term for itchiness and dermatitis, its long-term safety is incompletely established. It has been found to have a faster onset and cause less gastrointestinal issues than cyclosporine. There is some off-label use of oclacitinib to treat asthma and allergic dermatitis in cats, but its efficacy has not been established.
=== 1991 === January 5: The First South Ossetia War begins. January 26: Siad Barre was ousted from office, ending the Somali Democratic Republic and beginning the Somali Civil War. February 9: Lithuania holds an independence referendum with a majority voting in favor. February 28: Gulf War ends. March 1: Post-Gulf War uprisings in Iraq occurred. March 3: Estonia and Latvia hold an independence referendum with a majority voting to restore independence. March 23: The Sierra Leone Civil War begins. March 31: Georgia holds an independence referendum with a majority voting for independence from the Soviet Union but is boycotted by most Abkhazians and South Ossetians. The Croatian War of Independence begins, marking the breakup of Yugoslavia. April 9: Georgia declares independence from the Soviet Union. May 19: Croatia holds an independence referendum with a majority voting in favor of independence. May 21: Rajiv Gandhi was assassinated. June 12: Party of Labour of Albania, the ruling party of Albania, is dissolved. June 27: Slovenia fought a ten day war against Yugoslavia, marking the beginning of the breakup of Yugoslavia. July 1: Warsaw Pact is dissolved. July 31: The START I Treaty is ratified. August 19: Soviet coup attempt of 1991. A coup occurs in response to a new union treaty to be signed on August 20. August 22: The coup is ended. August 24: Ukrainian Soviet Socialist Republic declares its independence from the Soviet Union renaming itself Ukraine that day as well.
==== Unemployment ==== According to the U.S. Department of Labor Bureau of Labor Statistics, the unemployment rate is 8.3% as of October 2017. In the 20th century, the unemployment rate was around 5%, according to the U.S. Department of Labor's archives.
Sources: en.wikipedia.org
Some cytosolic proteins are recruited to different cellular membranes by recognizing certain types of lipid found within a given membrane. Binding of a protein to a specific lipid occurs via specific membrane-targeting structural domains that occur within the protein and have specific binding pockets for the lipid head groups of the lipids to which they bind. This is a typical biochemical protein–ligand interaction, and is stabilized by the formation of intermolecular hydrogen bonds, van der Waals interactions, and hydrophobic interactions between the protein and lipid ligand. Such complexes are also stabilized by the formation of ionic bridges between the aspartate or glutamate residues of the protein and lipid phosphates via intervening calcium ions (Ca2+). Such ionic bridges can occur and are stable when ions (such as Ca2+) are already bound to a protein in solution, prior to lipid binding. The formation of ionic bridges is seen in the protein–lipid interaction between both protein C2 type domains and annexins..
While liquids do not exhibit long-range ordering as in a crystalline lattice, they do possess short-range order, which persists over a few molecular diameters. In all liquids, excluded volume interactions induce short-range order in molecular positions (center-of-mass coordinates). Classical monatomic liquids like argon and krypton are the simplest examples. Such liquids can be modeled as disordered "heaps" of closely packed spheres, and the short-range order corresponds to the fact that nearest and next-nearest neighbors in a packing of spheres tend to be separated by integer multiples of the diameter. In most liquids, molecules are not spheres, and intermolecular forces possess a directionality, i.e., they depend on the relative orientation of molecules. As a result, there is short-ranged orientational order in addition to the positional order mentioned above. Orientational order is especially important in hydrogen-bonded liquids like water. The strength and directional nature of hydrogen bonds drives the formation of local "networks" or "clusters" of molecules. Due to the relative importance of thermal fluctuations in liquids (compared with solids), these structures are highly dynamic, continuously deforming, breaking, and reforming. While ordinary liquids lack long-range order, some materials exhibit intermediate behavior. Liquid crystals, for example, flow like liquids but exhibit long-range orientational alignment of their molecules. Unlike solids, they lack long-range translational order, yet their anisotropic properties set them apart from conventional liquids.
On 5 January 2026, the Venezuelan government issued an emergency order to police to arrest anyone who supported the US attack and mobilized colectivos (pro-government paramilitaries) who established roadblocks and searched cars and people. Fourteen journalists were detained, but 13 of them were later released. On 6 January, gunfire broke out in Caracas as the ministry of communication announced that police fired upon one of their own military drones "flying without permission" but that the drone suffered no damage.
=== Biomonitoring === Parmotrema perlatum is sensitive to air pollution, making it a useful bioindicator. This sensitivity is utilised in the "Hawksworth and Rose" scale, which estimates mean winter sulphur dioxide (SO2) levels in England and Wales by observing lichens on acidic and nutrient-poor bark. According to this scale, P. perlatum is found only in zones 8 to 10, indicating areas with the lowest SO2 concentrations, less than 35 micrograms per cubic metre (μg/m3). A 2022 study analyzed the effects of SO2 and nitrogen dioxide (NO2) fumigation on the chlorophyll content of Parmotrema perlatum collected from the Mount Lawu volcano in Indonesia. The results indicated that increased exposure to these pollutants leads to a significant reduction in chlorophyll levels. The study demonstrated that SO2 and NO2 negatively impact the physiological processes of the lichen, particularly its photosynthetic efficiency, demonstrating the sensitivity of P. perlatum to air pollution. Parmotrema perlatum has been effectively used in biomonitoring studies to assess environmental radioactivity. Research conducted in Turkey found that this lichen species retains radioactive caesium-137 (137Cs) from atmospheric deposition, such as fallout from the Chernobyl accident. The ecological half-life of 137Cs in Parmotrema perlatum was determined to be approximately 5.5 years, indicating its capability to monitor long-term radioactive contamination in the environment.
Sources: en.wikipedia.org
No major regulatory agency has approved AOD-9604 as a medicine. It is treated as an experimental peptide in research settings. Some countries restrict its sale or import.
The World Anti-Doping Agency classifies growth hormone fragments, including AOD-9604, as prohibited substances. The classification reflects concern about potential performance-enhancing use. Athletes are subject to testing for such peptides.
Detection typically uses liquid chromatography combined with mass spectrometry. These methods separate the peptide and identify it by mass. Immunoassays may screen samples but require confirmation by a more specific technique.
It is a synthetic peptide fragment derived from the C-terminal region of human growth hormone, commonly referred to as hGH fragment 176-191. It has been investigated for effects on fat metabolism, but it is not an approved medication in most jurisdictions.