If you have been reading about synthetic peptide and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-01-25. Numbers and descriptions here follow the published literature rather than marketing material.
AOD-9604 is a synthetic peptide whose structure corresponds to a C-terminal segment of human growth hormone. It is often described as hGH fragment 176-191, a 16-amino-acid sequence. The peptide was designed to isolate a region of hGH associated with fat metabolism while avoiding the full hormone's growth-promoting actions. Laboratory and commercial materials typically present it as a lyophilized powder for research use. Its identity is defined by amino acid sequence, not by a single brand.
The fragment includes residues that can form an internal disulfide bond between two cysteine positions. This structural feature can influence how the peptide folds and how stable it is in solution. AOD-9604 differs from full-length hGH in size and receptor interactions; it does not contain the entire growth hormone sequence. Published descriptions sometimes use slightly different residue numbering, so sequence information should be checked against primary sources. The molecule is small compared with intact hGH, which affects analytical detection and purification approaches.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Based on the C-terminal region of human growth hormone. |
| Amino acid length | 16 residues | Often described as hGH fragment 176-191. |
| Appearance | Lyophilized powder | Typically white to off-white; exact appearance depends on grade. |
| Solubility | Soluble in water | Aqueous solubility depends on pH, ionic strength, and preparation. |
| Typical storage | -20 °C or lower | Lyophilized peptide is usually kept cold and dry; solutions may require freezing. |
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.
Detection of AOD-9604 in biological samples relies on analytical techniques capable of distinguishing a small synthetic peptide from related endogenous sequences. Liquid chromatography coupled with tandem mass spectrometry is commonly used for confirmatory analysis. Sample preparation may involve immunoaffinity enrichment or solid-phase extraction to concentrate the peptide. Because the molecule is small and may be present at low concentrations, assay sensitivity and specificity are ongoing analytical challenges. Laboratories also validate methods against reference materials when available.
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.
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.
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.
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.
== Regulation == IGFBP-3 levels in human serum are, like IGF-1, dependent on growth hormone (GH); for example, serum IGFBP-3 is increased in acromegaly and low in GH-deficient children. However, IGFBP-3 gene expression in human liver is GH-independent. Because it is stabilized in human serum by forming complexes with IGF-1 and ALS, which are both GH-dependent, serum IGFBP-3 also appears regulated by GH. Its production by some non-hepatic tissues may also be directly GH-regulated. Immunoassays for serum IGFBP-3 are often used as part of the diagnosis of childhood GH-deficiency. The most widely studied IGFBP3 polymorphism, at nucleotide-202 in the promoter region, is significantly associated with circulating IGFBP-3 levels, although the mechanism is unclear. In some studies circulating IGFBP-3 also appears to be nutritionally regulated, although this may not be seen at the mRNA level. IGFBP-3 has been identified in human lymph, nipple aspirate, milk, amniotic fluid, follicular fluid, seminal plasma, urine, peritoneal dialysate, synovial fluid, tear fluid, and cerebrospinal fluid, in addition to serum. Many factors increase IGFBP-3 production by cells, including transforming growth factor-β (TGFβ), tumor necrosis factor-α, vitamin D, retinoic acid, IGF-1, and stimuli such as chemotherapy that activate the tumor suppressor p53. Estrogen inhibits IGFBP-3 production, and its tissue levels are lower in estrogen receptor (ER)-positive breast cancers than in ER-negative cancers.
Neuroendocrine tumors (NETs) are localised clinically using a range of DOTA based radiopharmaceuticals. For PET imaging these are typically Gallium-68 based. A commercial 64Cu-DOTA-TATE product has been FDA approved for localization of somatostatin receptor positive NETs since 2020.
==== Renewed clashes ==== The conflict between Houthis and Salafis in Saada Governorate was renewed in October and November. Saada government officials accused Houthi fighters of attacking a Salafi mosque in Dammaj in an attempt to drive the Sunnis out, while the Houthis accused the Salafis of using the religious institute as a staging ground for foreign Sunni fighters. The government attempted to intervene to stop the fighting. Sectarian fighting in Al Jawf Governorate lasted throughout the year. Dhamar Governorate also saw clashes between the Houthis and Salafis toward the end of the year.
Sources: en.wikipedia.org
== Structure and function == CCS is composed of three domains. Domain I is located on the N-terminus and contains the MXCXXC Cu binding sequence. It has been determined to be necessary for function of CCS but its specific role is currently unknown. The structure of domain II greatly resembles that of SOD1 which allows it to perform the function of binding to SOD1. Domain III contains a CXC Cu binding motif and performs the Cu insertion and subsequent disulfide oxidation of SOD1. When CCS docks to SOD1, cysteine 244 of CCS and 57 of SOD1 form a disulfide linkage. This disulfide bond is then transferred to form a disulfide bridge between cysteine 57 and 146 of SOD1. CCS's catalytic oxidation of SOD1's disulfide bridge can only be performed in the presence of oxygen. Furthermore, the disulfide linkage of SOD1 can be performed without the presence of CCS but requires oxygen and is much slower. Additionally, CCS is proposed to help the proper folding of SOD1 by binding in the apo-state. As well as SOD1, CCS (gene) has been shown to interact with APBA1.
Writing for The Guardian, Seumas Milne stated the result of the post–Cold War narrative that Stalin and Hitler were twin evils, therefore communism is as monstrous as Nazism, "has been to relativise the unique crimes of Nazism, bury those of colonialism and feed the idea that any attempt at radical social change will always lead to suffering, killing and failure." Other leftists, including some Marxist–Leninists, apply self-criticism, and have at times criticised Marxist–Leninist praxis and some actions by Marxist–Leninist governments, while acknowledging its advancements, emancipatory acts such as their support of labour rights, women's rights, anti-imperialism, democratic efforts, egalitarian achievements, modernisation, and the creation of mass social programs for education, health, housing, and jobs as well as the increase of living standards.
== Isoform diversity == Amyloid-beta precursor protein is highly versatile with several isoforms generated through alternative splicing of its mRNA. The primary isoforms include APP695, APP751, and APP770, differing in their inclusion of certain exons, mainly exon 7 and 8. APP695 is predominantly expressed in neuronal cells and is crucial for normal neuronal function. APP751 and APP770 are more widely expressed in non-neuronal tissues but exhibit distinct expression patterns during neuron differentiation. The differential expression of these isoforms plays a significant role in cellular processes such as neurodevelopment, synaptic plasticity, and the pathogenesis of Alzheimer's disease. Understanding the isoform diversity of APP is essential for deciphering its various physiological and pathological roles.
Sources: en.wikipedia.org
It is a synthetic peptide based on a C-terminal fragment of human growth hormone. It is commonly referred to as hGH fragment 176-191 and is studied for metabolic effects rather than growth effects.
No. It represents only a short portion of the hGH sequence and lacks the full hormone's structure. As a result, its biological activity and regulatory status differ from those of prescription hGH.
The exact peptide is not typically described as a circulating hormone; it is a synthetic construct based on a natural sequence. Fragments of hGH can exist in laboratory or metabolic contexts, but AOD-9604 itself is manufactured for research.
No. It is not approved as a therapeutic drug by major regulators. It is sold for research purposes in many settings, which is not the same as clinical approval.