This is a working overview of hGH fragment, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-06-05. Anything still debated is marked as such rather than presented as settled.
In laboratory settings, AOD-9604 is commonly supplied as a lyophilized powder and stored cold to limit degradation. Reconstituted solutions are typically kept refrigerated or frozen, depending on the buffer and concentration, and protected from repeated freeze-thaw cycles. Stability can be influenced by pH, temperature, and the presence of proteases. Purity is usually assessed by high-performance liquid chromatography and mass spectrometry. These practices support reproducibility, but they do not imply safety or efficacy for any human use.
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.
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.
| 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. |
=== Reductive half === The action of GR proceeds through two distinct half reactions, a reductive half mechanism followed by an oxidative half. In the first half, NADPH reduces FAD present in GSR to produce a transient FADH− anion. This anion then quickly breaks a disulfide bond of Cys58 - Cys63, forming a short lived covalent bond a stable charge-transfer complex between the flavin and Cys63. The now oxidized NADP+ is released and is subsequently replaced by a new molecule of NADPH. This is the end of the so-called reductive half of the mechanism.
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Sources: en.wikipedia.org
Pre-formed mediators stored in granules biogenic amines (histamine, serotonin, dopamine) proteases (serine proteases including tryptase and chymase, aspartic acid proteases, cysteine proteases, metalloproteinases including CPA3) proteoglycans (heparin, chondroitin sulfate) cytokines (TNF, IL-4) growth factors (GM-CSF, bFGF, VEGF, NGF) lysosomal enzymes (β-hexosaminidase, β-glucuronidase, CD63) Newly synthesized inflammatory mediators lipid mediators (eicosanoids, thromboxane, LTB4, LTC4, PAF, PGD2) neuropeptides (CRH, VIP) growth factors (PDGF, GnRH) chemokines (MCP-1, eotaxin, TARC, RANTES) cytokines (IL-1, IL-3, IL-6, IL-18, SCF, TGF-β)
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=== 2nd Congress (1975) === The CLP held its 2nd Congress in November 1975. The Political Resolution at this Congress stated, "The struggle within the socialist camp is increasingly taking a national form – a form that makes ever more difficult the militant expressions of solidarity of the revolutionary proletariat within the socialist sector.” And, "Our Party … does not choose national sides in this ... struggle that is taking place within the socialist camp. Our Party unconditionally supports revolution and conditionally supports states.” This Political Resolution also discussed globalization, with the CLP viewing it as a the consolidation of an international bourgeoisie. Just before the 3rd Congress, ten members left the CLP. Called the "action faction,” this faction wanted the CLP to become more active in and "build the movement.” The CLP position was that the time was not right for direct action. Instead, the CLP needed to spend more time building class consciousness.. Tension between these two perspectives continued throughout the life of the CLP.
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.
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.