A practical reference on synthetic peptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-09-27. Anything still debated is marked as such rather than presented as settled.
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.
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.
Clinical development of AOD-9604 included trials in people with obesity. Reports from early-phase and mid-phase studies described modest or inconsistent changes in body weight. A phase IIb program did not meet its primary endpoint, and the compound was not approved for medical use. Differences in formulation, delivery route, and participant characteristics may explain some of the variation. Later investigations explored whether the peptide might have effects in other tissues, including cartilage.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Derived from a fragment of human growth hormone |
| Sequence basis | hGH residues 176-191 | Commonly described as a 16-amino-acid fragment |
| Appearance | White to off-white powder | Typical for lyophilized research peptides |
| Solubility | Soluble in water or aqueous buffer | Exact solubility depends on pH and purity |
| Common synonyms | AOD9604; hGH 176-191 | Spelling and punctuation vary across sources |
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.
Stability of AOD-9604 depends on storage conditions. Lyophilized powder is generally more stable than reconstituted solution. Recommended storage is typically at -20°C or lower, protected from light and moisture. Repeated freeze-thaw cycles can cause aggregation or degradation. In solution, the peptide may be susceptible to hydrolysis or oxidation, so aliquoting and cold storage are common practices. Researchers often add stabilizers such as mannitol or trehalose during lyophilization to improve shelf life.
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.
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 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.
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.
=== Quantitative analysis === Quantitative analysis is the measurement of the quantities of particular chemical constituents present in a substance. Quantities can be measured by mass (gravimetric analysis) or volume (volumetric analysis).
Severe adverse effects of EMP are thromboembolic and cardiovascular complications including pulmonary embolism, deep vein thrombosis, stroke, thrombophlebitis, coronary artery disease (ischemic heart disease; e.g., myocardial infarction), thrombophlebitis, and congestive heart failure with fluid retention. EMP produces cardiovascular toxicity similarly to diethylstilbestrol, but to a lesser extent in comparison at low doses (e.g., 280 mg/day oral EMP vs. 1 mg/day oral diethylstilbestrol). The prostate cancer disease state also increases the risk of thromboembolism, and combination with docetaxel may exacerbate the risk of thromboembolism as well. Meta-analyses of clinical trials have found that the overall risk of thromboembolism with EMP is 4 to 7%, relative to 0.4% for chemotherapy regimens without EMP. Thromboembolism is the major toxicity-related cause of discontinuation of EMP. Anticoagulant therapy with medications such as aspirin, warfarin, unfractionated and low-molecular-weight heparin, and vitamin K antagonists can be useful for decreasing the risk of thromboembolism with EMP and other estrogens like diethylstilbestrol and ethinylestradiol. Adverse liver function tests are commonly seen with EMP, but severe liver dysfunction is rare with the medication. Central nervous system side effects are rarely seen with EMP, although enlarged ventricles and neuronal pigmentation have been reported in monkeys treated with very high doses of EMP (20–140 mg/kg/day) for 3 to 6 months. EMP does not appear to have cytostatic effects in normal brain tissue.
Formation of additional capillaries and larger blood vessels (angiogenesis) is a major mechanism by which a cancer may help to enhance its own growth. Disorders of retinal capillaries contribute to the pathogenesis of age-related macular degeneration. Reduced capillary density (capillary rarefaction) occurs in association with cardiovascular risk factors and in patients with coronary heart disease.
Sigma-Aldrich Fine Chemicals (SAFC) is the fine chemical supply branch of Sigma-Aldrich specializing in raw materials for cell culture products; customized services for raw materials, manufacturing of active pharmaceutical ingredients. Sigma Life Science provides products such as custom DNA/RNA oligos; custom DNA and LNA probes; siRNA; isotopically-labelled peptides and peptide libraries. Sigma Advanced Genetic Engineering (SAGE) Labs was a division within Sigma-Aldrich that specializes in genetic manipulation of in vivo systems for special research and development applications. It was formed in 2008 to investigate zinc finger nuclease technology and its application for disease research models. Located in St. Louis, Missouri, SAGE Labs have developed knockout rats for the study of human diseases and disorders (such as autism), which are sold for up to US$95,000. SAGE also announced its first successful effort in creating a "knockout rabbit". Its facilities include a specific pathogen free, biosecure vivarium as well as research and development labs. SAGE Labs was acquired by Horizon Discovery Group in 2014. Carbolabs produces research quantities of chemicals produced by phosgenation reactions. The company was acquired in 1998. BioReliance provides testing and manufacturing services to pharmaceutical and biopharmaceutical companies that span the product cycle from early pre-clinical development to licensed production. The company was acquired by Sigma Aldrich in January 2012.
Sources: en.wikipedia.org
=== Panic disorder === The efficacy of fluoxetine in the treatment of panic disorder was demonstrated in two 12-week randomized multicenter phase III clinical trials that enrolled patients diagnosed with panic disorder, with or without agoraphobia. In the first trial, 42% of subjects in the fluoxetine-treated arm were free of panic attacks at the end of the study, vs. 28% in the placebo arm. In the second trial, 62% of fluoxetine-treated patients were free of panic attacks at the end of the study, vs. 44% in the placebo arm.
The effect of botulinum toxin type-A on reducing and eliminating forehead wrinkles was first described and published by Richard Clark, MD, a plastic surgeon from Sacramento, California. In 1987 Clark was challenged with eliminating the disfigurement caused by only the right side of the forehead muscles functioning after the left side of the forehead was paralyzed during a facelift procedure. This patient had desired to look better from her facelift, but was experiencing bizarre unilateral right forehead eyebrow elevation while the left eyebrow drooped, and she constantly demonstrated deep expressive right forehead wrinkles while the left side was perfectly smooth due to the paralysis. Clark was aware that botulinum toxin was safely being used to treat babies with strabismus and he requested and was granted FDA approval to experiment with botulinum toxin to paralyze the moving and wrinkling normal functioning right forehead muscles to make both sides of the forehead appear the same. This study and case report of the cosmetic use of botulinum toxin to treat a cosmetic complication of a cosmetic surgery was the first report on the specific treatment of wrinkles and was published in the journal Plastic and Reconstructive Surgery in 1989. Editors of the journal of the American Society of Plastic Surgeons have clearly stated "the first described use of the toxin in aesthetic circumstances was by Clark and Berris in 1989." J. D. and J. A.
=== Sri Lankan === Soy sauce (Sinhala: සෝයා සෝස්) is a popular food product used in Sri Lanka and is a major ingredient used in the nationally popular street food dish kottu. Soy sauce has largely been produced by the Sri Lankan Chinese community but its production has also spread to other communities in Sri Lanka. Soy sauce production in Sri Lanka is the same as the production of soy sauce in Indonesia. Fermentation occurs over a period of three months. The soy beans which are steeped in brine are then pressed to obtain a liquid sauce.
Sources: en.wikipedia.org
No, it is a synthetic peptide fragment corresponding to a small portion of hGH. It is not the full 191-amino-acid hormone and does not reproduce all of hGH's effects.
It is commonly described as a 16-amino-acid peptide based on residues 176-191 of human growth hormone. Some sources vary in notation, so checking the stated sequence is useful.
It is not typically described as a standalone natural hormone. The sequence is derived from the C-terminal region of human growth hormone, but the synthetic peptide is a laboratory-made construct.
No. Major drug regulators have not approved AOD-9604 for weight loss or any other therapeutic indication. It remains an investigational compound studied in research settings.