This is a working overview of synthetic peptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-05-10 and is reviewed periodically as new material appears.
AOD-9604 is a synthetic peptide that corresponds to a short section of human growth hormone. It is commonly identified as hGH fragment 176-191 because its sequence matches residues at the C-terminal end of the hormone. The molecule contains sixteen amino acids and is made by solid-phase peptide synthesis. Researchers study it for metabolic effects rather than for the growth-promoting actions associated with full human growth hormone. Its small size distinguishes it from the complete 191-amino-acid hormone.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Common name | AOD-9604 | Development code used in scientific literature. |
| Chemical class | Synthetic peptide | Fragment of human growth hormone. |
| Amino acid length | 16 residues | Matches hGH region 176-191. |
| Appearance | White to off-white powder | Typical lyophilized peptide solid. |
| Solubility | Soluble in water | Dissolves in aqueous media; exact behavior depends on salt form. |
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 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.
AOD9604 is a synthetic peptide modeled on the C-terminal region of human growth hormone. It corresponds to a short sequence near the end of the 191-amino-acid hormone, often described as residues 176–191 or a related fragment. Researchers designed it to separate metabolic effects from the growth-promoting actions of full-length growth hormone. Early work in the 1990s explored it as a candidate for weight and lipid disorders. It is not a naturally circulating hormone fragment produced in large amounts.
Laboratory studies have reported that AOD9604 can increase lipolysis and reduce lipid accumulation in fat cells. The precise molecular target remains uncertain, and the compound does not appear to activate the growth hormone receptor in the same way as full-length hGH. Proposed mechanisms include effects on beta-adrenergic signaling and enzymes involved in fatty acid synthesis, but these pathways are not firmly established. Because most evidence comes from cell and animal models, whether the same effects occur in humans is an open question.
Clinical development of AOD9604 included trials in people with obesity, but the results did not lead to approval as a prescription medicine in major markets. Interest later shifted to research settings and to unapproved products marketed for body composition. Regulatory agencies have questioned whether the peptide qualifies as a dietary ingredient, and some have issued warnings about its presence in supplements. Long-term human safety data are limited, and questions about efficacy, dosing, and target populations remain unresolved.
AOD-9604 is a synthetic peptide whose sequence is modeled on the C-terminal region of human growth hormone. Published descriptions commonly place it as a modified fragment corresponding to hGH amino acids 176–191, with a tyrosine residue added or retained at the N-terminus to support detection and handling. It is not intact growth hormone and lacks the full receptor-binding architecture of the parent protein. The molecule was developed as a research candidate for metabolic studies rather than as a replacement for growth hormone therapy. Its identity is defined by its amino acid sequence rather than by any single commercial preparation.
AOD-9604 drew attention in the 1990s and 2000s as a potential anti-obesity agent. Early work explored both injectable and oral routes, which is unusual for a peptide of this size. Animal studies reported changes in fat metabolism without the growth-promoting or insulin-like effects associated with full-length growth hormone. Subsequent human trials produced mixed or modest results, and the compound did not obtain regulatory approval for weight management in major markets. It remains known mainly through research literature, sports anti-doping listings, and non-approved supplement advertising.
=== Obstructive sleep apnea in pregnancy === Sleep apnea can result in intermittent hypoxia and has been increasing in prevalence due in part to the obesity epidemic. The known maternal risk factors for autism diagnosis in her offspring are similar to the risk factors for sleep apnea. For example, advanced maternal age, maternal obesity, maternal type 2 diabetes and maternal hypertension all increase the risk of autism in her offspring. Likewise, these are all known risk factors for sleep apnea. One study found that gestational sleep apnea was associated with low reading test scores in children and that this effect may be mediated by an increased risk of the child having sleep apnea themselves. Another study reported low social development scores in 64% of infants born to mothers with sleep apnea compared to 25% of infants born to controls, suggesting sleep apnea in pregnancy may have an effect on offspring neurodevelopment. There was also an increase in the amount of snoring the mothers with sleep apnea reported in their infants when compared to controls. Children with sleep apnea have "hyperactivity, attention problems, aggressivity, lower social competency, poorer communication, and/or diminished adaptive skills". One study found significant improvements in ADHD-like symptoms, aggression, social problems and thought problems in autistic children who underwent adenotonsillectomy for sleep apnea. Sleep problems in autism have been linked in a study to brain changes, particularly in the hippocampus, though this study does not prove causation.
Former CIA director John O. Brennan called it "outrageous that we are threatening Denmark" and that there is a "sense of shame" among Americans over Trump's international behaviour. US Republican senator Thom Tillis and Democratic senator Jeanne Shaheen, co-chairs of the Senate NATO Observer Group, said that "the United States must honor its treaty obligations and respect Greenland and Denmark's sovereignty and territorial integrity". Republican senator Roger Wicker, the Senate Armed Services chair, said Trump's threats to seize Greenland was "a topic that should be dropped" and cautioned Trump against spending time "antagonizing allies". After meeting Danish officials, Wicker said it was clear that there was no room for negotiation and that Trump's attempt to obtain Greenland was not realistic.
==== Chemical secretion ==== Recognition of MAMPs by PRRs can activate tissue resident macrophages to secrete proinflammatory cytokines that recruit other immune cells. Among the PRRs, TLRs play a major role in signal transduction leading to cytokine production. The binding of MAMPs to TLR triggers a series of downstream events that eventually activates transcription factor NF-κB and results in transcription of the genes for several proinflammatory cytokines, including IL-1β, IL-6, TNF-α, IL-12B, and type I interferons such as IFN-α and IFN-β. Systemically, IL-1β, IL-6, and TNF-α induce fever and initiate the acute phase response in which the liver secretes acute phase proteins. Locally, IL-1β and TNF-α cause vasodilation, where the gaps between blood vessel epithelial cells widen, and upregulation of cell surface adhesion molecules on epithelial cells to induce leukocyte extravasation. Additionally, activated macrophages have been found to have delayed synthesis of prostaglandins (PGs) which are important mediators of inflammation and pain. Among the PGs, anti-inflammatory PGE2 and pro-inflammatory PGD2 increase the most after activation, with PGE2 increasing expression of IL-10 and inhibiting production of TNFs via the COX-2 pathway. Neutrophils are among the first immune cells recruited by macrophages to exit the blood via extravasation and arrive at the infection site. Macrophages secrete many chemokines such as CXCL1, CXCL2, and CXCL8 (IL-8) that attract neutrophils to the site of infection.
Sources: en.wikipedia.org
The New Union Treaty (Russian: Новый союзный договор, romanized: Novyy soyuznyy dogovor) was a 1990 draft treaty that would have replaced the 1922 Treaty on the Creation of the Union of Soviet Socialist Republics (USSR) to salvage and reform the USSR. The preparation of this treaty was known as the Novo-Ogaryovo process, named after Novo-Ogaryovo, a governmental estate where the work on the document was carried out and where Soviet President and CPSU General Secretary Mikhail Gorbachev talked with leaders of Union republics. A ceremony of the Russian SFSR signing the treaty was scheduled for 20 August 1991, but was prevented by the August Coup. In its aftermath, the Soviet Union ultimately dissolved by December of the same year, and the Commonwealth of Independent States was set up in its place.
It thus seems likely that while δ-opioid agonists can produce respiratory depression at very high doses, at lower doses they have the opposite effect, a fact that may make mixed mu/delta agonists such as DPI-3290 potentially very useful drugs that might be much safer than the μ agonists currently used for pain relief. Many delta agonists may also cause seizures at high doses, although not all delta agonists produce this effect. Of additional interest is the potential for delta agonists to be developed for use as a novel class of antidepressant drugs, following robust evidence of both antidepressant effects and also upregulation of BDNF production in the brain in animal models of depression. These antidepressant effects have been linked to endogenous opioid peptides acting at δ- and μ-opioid receptors, and so can also be produced by enkephalinase inhibitors such as RB-101. However, in human models the data for antidepressant effects remains inconclusive. In the 2008 Phase 2 clinical trial by Astra Zeneca, NCT00759395, 15 patients were treated with the selective delta agonist AZD 2327. The results showed no significant effect on mood suggesting that δ-opioid receptor modulation might not participate in the regulation of mood in humans. However, doses were administered at low doses and the pharmacological data also remains inconclusive. Further trials are required. Another interesting aspect of δ-opioid receptor function is the suggestion of μ/δ-opioid receptor interactions. At the extremes of this suggestion lies the possibility of a μ/δ opioid receptor oligomer.
=== Schizophrenia === A very large percentage of schizophrenics smoke tobacco as a form of self-medication. Some studies suggest that a link exists between smoking and mental illness, citing the high incidence of smoking amongst those with schizophrenia and smoking lowering age of the onset of psychosis. In 2015, a meta-analysis found that smokers were at greater risk of developing psychotic illness. However, following the observation that smoking improves the condition of people with schizophrenia, in particular their working memory deficit, nicotine patches had been proposed as a way to treat schizophrenia.
=== 4 May === Explosions were reported in Kyiv and Odesa in another series of Russian air attacks. Ukraine claimed to have destroyed 18 out of the 24 drones launched, plus a reconnaissance drone, with only light damage to property; the drones were marked with messages such as "For Moscow" and "For the Kremlin". According to TASS, Ukrainian drones attacked and set ablaze the Ilsky refinery near Novorossiisk. The fire was extinguished without damage after two hours. Fighting broke out between Russian and Ukrainian delegates to the Parliamentary Assembly of the Black Sea Economic Cooperation in Ankara, Turkey. Ukrainian delegates had earlier waved Ukrainian flags during a speech by a Russian delegate. Later, Oleksandr Marikovski, a Ukrainian MP, physically assaulted a Russian official after the latter seized his flag. Ukraine for the first time intercepted a Russian Kh-47M2 Kinzhal hypersonic missile, following reports from Kyiv of a powerful explosion overnight. The Ukrainian Air Force said they shot it down using the Patriot missile system protecting the capital.
Sources: en.wikipedia.org
AOD-9604 is a synthetic peptide fragment of human growth hormone. It corresponds to the C-terminal region known as hGH 176-191 and is studied for metabolic effects. It is not an approved therapeutic drug.
No. It contains only a small portion of the human growth hormone sequence. The full hormone has 191 amino acids and many additional actions that the fragment does not share.
The name refers to the amino acid positions in the human growth hormone chain. The fragment spans residues 176 through 191 at the C-terminal end. This naming convention helps distinguish it from full-length hGH.
AOD-9604 is a synthetic peptide fragment of human growth hormone, corresponding to amino acids 176-191. It is studied for potential effects on fat metabolism, but it is not approved as a drug in most countries. Its exact mechanism remains under investigation.