A practical reference on hGH fragment: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2026-01-14 and is reviewed periodically as new material appears.
Identity and purity are usually assessed with reversed-phase high-performance liquid chromatography and mass spectrometry. Reversed-phase HPLC separates the peptide from related impurities and can estimate purity by ultraviolet absorbance, while mass spectrometry confirms the molecular mass and detects modifications. Peptide mapping, amino acid analysis, and disulfide mapping may be used when the sequence or disulfide arrangement must be verified. Because AOD9604 contains cysteine residues, oxidation and disulfide isomers are possible quality concerns in synthetic batches.
Quality varies among research-grade suppliers, so certificates of analysis and independent testing are important for verification. A typical certificate reports purity by HPLC, identity by mass spectrometry, appearance, and sometimes residual solvents or water content. AOD9604 is often sold as a research chemical not intended for human consumption, and labels can be inaccurate. Common misconceptions include treating the peptide as a form of growth hormone, assuming supplement status, or expecting approved-drug quality from unregulated products.
AOD-9604 is prohibited in sport by the World Anti-Doping Agency under the peptide hormone class. Its presence in a sample can be detected through mass spectrometry-based methods, although the exact assay depends on the laboratory. In research settings, material is often supplied as a lyophilized powder for reconstitution. Buyers and researchers should note that products labeled AOD-9604 may vary in purity and actual peptide content. Analytical certificates and independent testing are common ways to verify identity, but no global harmonized standard exists for all commercial lots.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized form; visual inspection |
| Solubility | Soluble in water and aqueous buffers | Depends on pH, purity, and counterion |
| Typical storage | -20 °C or below, desiccated | Protect from light; avoid repeated freeze-thaw after reconstitution |
| Common analytical method | Reversed-phase HPLC and mass spectrometry | Purity by HPLC; identity and mass by LC-MS or MALDI-TOF |
| Common synonyms | hGH fragment 176–191; AOD-9604 | Names vary in research and product labeling |
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.
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.
Sickle-cell anemia is caused by a point mutation in the β-globin chain of hemoglobin, causing the hydrophilic amino acid glutamic acid to be replaced with the hydrophobic amino acid valine at the sixth position. The β-globin gene is found on the short arm of chromosome 11. The association of two wild-type α-globin subunits with two mutant β-globin subunits forms hemoglobin S (HbS). Under low-oxygen conditions (being at high altitude, for example), the absence of a polar amino acid at position six of the β-globin chain promotes the non-covalent polymerisation (aggregation) of hemoglobin, which distorts red blood cells into a sickle shape and decreases their elasticity. Hemoglobin is a protein found in red blood cells, and is responsible for the transportation of oxygen through the body. There are two subunits that make up the hemoglobin protein: beta-globins and alpha-globins. Beta-hemoglobin is created from the genetic information on the HBB, or "hemoglobin, beta" gene found on chromosome 11p15.5. A single point mutation in this polypeptide chain, which is 147 amino acids long, results in the disease known as Sickle Cell Anemia. Sickle-cell anemia is an autosomal recessive disorder that affects 1 in 500 African Americans, and is one of the most common blood disorders in the United States. The single replacement of the sixth amino acid in the beta-globin, glutamic acid, with valine results in deformed red blood cells.
Electrochromatography is a chemical separation technique in analytical chemistry, biochemistry and molecular biology used to resolve and separate mostly large biomolecules such as proteins. It is a combination of size exclusion chromatography (gel filtration chromatography) and gel electrophoresis. These separation mechanisms operate essentially in superposition along the length of a gel filtration column to which an axial electric field gradient has been added. The molecules are separated by size due to the gel filtration mechanism and by electrophoretic mobility due to the gel electrophoresis mechanism. Additionally there are secondary chromatographic solute retention mechanisms.
== Science and technology == 4 Vesta, an asteroid Vesta family, group of asteroids that includes 4 Vesta Vesta (rocket), a French sounding rocket The Vesta parallel file system, a precursor of IBM's GPFS Vesta (software configuration management) (developed 1993), advanced configuration management system released by Compaq Vesta, a genus of flowering plant in the family Araceae Vesta longifolia, sole species of the genus Vesta Vestas (founded 1945), Danish manufacturer of wind turbines
=== IRAP catalytic site inhibitors === Peptidomimetics The first reported IRAP inhibitors were designed as angiotensin IV (AngIV) analogs. In 2006, Axén et al published a macrocyclized version of an AngIV derivative (Compound 1) which confers metabolic stability together with high affinity for IRAP (Ki = 25.8 nM). Under a similar scope Lukaszuk et al produced compound AL-11, which was able to inhibit IRAP (Ki = 27.5 nM) and displayed around 200-fold selectivity over APN. Further structural modifications on the AngIV-based inhibitors from Anderson et al led to optimized macrocycle HA08 (available crystal structure within IRAP, Figure 2) with excellent IRAP potency (Ki = 3.3 nM) and selectivity over APN, but poor metabolic stability.
==== Androgen receptor ==== Although it functions as an endogenous precursor to more potent androgens such as testosterone and DHT, DHEA has been found to possess some degree of androgenic activity in its own right, acting as a low affinity (Ki = 1 μM), weak partial agonist of the androgen receptor (AR). However, its intrinsic activity at the receptor is quite weak, and on account of that, due to competition for binding with full agonists like testosterone, it can actually behave more like an antagonist depending on circulating testosterone and dihydrotestosterone (DHT) levels, and hence, like an antiandrogen. However, its affinity for the receptor is very low, and for that reason, is unlikely to be of much significance under normal circumstances.
Sources: en.wikipedia.org
=== Phenethylamines === Drugs containing the phenethylamine moiety bear close structural resemblance to dopamine but substitution on the benzene ring gives rise to drugs with a much higher affinity for serotonin receptors.
He called the bill "crony capitalism" and set several conditions for acceptance of the bill: "Companies must agree to issue warrants or equity stakes to the federal government; they must commit to not buying back their own stock, outsourcing American jobs overseas or repealing existing collective bargaining agreements; and they must remain neutral in any union organizing efforts". In April 2023, Sanders endorsed Biden in the 2024 United States presidential election, and after Biden withdrew from the race, Sanders endorsed Harris for president at the Democratic National Convention. Sanders attempted to appeal to pro-Palestinian critics of Harris by saying, "I promise you, after Kamala wins, we will together do everything that we can to change US policy toward Netanyahu", and emphasizing Donald Trump's policies on climate change, minimum wage, and tax cuts for the wealthy.
In his book TiHKAL (Tryptamines I Have Known and Loved), Alexander Shulgin lists the same dose range of 10 to 20 mg orally and duration of 3 to 6 hours for psilocin, psilocybin, and 4-AcO-DMT. Another publication gave a 4-AcO-DMT dose range of 10 to 15 mg orally, with a typical dose of 12.5 mg orally, and a duration of about 5 to 8 hours. A further source gave a dose range for the drug of 5 to 30 mg orally, an onset of 15 to 40 minutes, and a duration of 4 to 7 hours. 4-AcO-DMT is a prodrug of psilocin similarly to psilocybin and its effects are reported to be similar or identical to those of psilocybin and psilocybin-containing mushrooms. However, it is said to produce less nausea and body load than psilocybin-containing mushrooms. The drug is also often described as having a faster onset and shorter duration than psilocybin. 4-AcO-DMT exposure results in modestly lower peripheral plasma concentrations of psilocin by weight than psilocybin in animals when they are given at equimolar doses. Specific effects of 4-AcO-DMT have been reported to include psychedelic visuals, closed-eye imagery, synesthesia, insights, disembodiment, euphoria, feelings of bliss and unity, oceanic boundlessness, ego dissolution, sedation, cognitive impairment, and spiritual experiences, among others. Adverse effects have been reported to include psychological side effects such as anxiety, paranoia, and low mood as well as gastrointestinal side effects such as nausea and vomiting.
==== Usage of Protein Nanoprobes to Study Protein-Protein Interactions with Mass Spectrometry ==== Protein was studied using a protein nanoprobe (that enables cross-linking) that introduced photo-methionine within the protein (during the recombinant expression) which lead to the protein keeping its reserved structure while having the ability to be mapped out for its interactions. The model was used as a region of contact surface that is involved in a well-known interaction (homodimerization) between two molecules of 14-3-3ζ protein. Once the photo-methionine is introduced and has become activated using UV-light, it can cross-link with no specificity (meaning no group) and the links have zero-length. High resolution mass spectrometry or MS can (even MS/MS) be used then to determine the cross-linked residues and the reaction radius; allowing the researchers to characterize and research the homodimerization of the protein. The usage of the high-resolution MS with photo-methionine has its advantages as it again allows the protein to be in its native state, there are reasonable time scales while using small quantities of the protein. There are also fewer limitations on the reaction specificity and restrictions using a photo-active cross-linker (photo-methionine) compared to chemical cross-linking. This method of combined photo-initiated cross-linking from the protein nanoprobe in tandem with MS could be useful to characterize not only homodimer formation but also oligomers and in theory; heteromers (such as the composition of the protein-protein mixture and its functionality).
Sources: en.wikipedia.org
Lyophilized AOD9604 is generally kept at -20 °C or colder, desiccated, and protected from light. Reconstituted solutions are usually refrigerated and handled to minimize repeated freeze-thaw cycles. These are general laboratory handling practices, not instructions for human use.
Mass spectrometry, such as LC-MS or MALDI-TOF, confirms the molecular mass and can reveal sequence-related impurities. Reversed-phase HPLC is used for purity, and peptide mapping or amino acid analysis can support sequence identity. No single method establishes every quality attribute.
No. AOD9604 is a short synthetic fragment of the hGH sequence, not the full 191-amino-acid hormone. It lacks the regions that mediate hGH receptor activation and growth-promoting effects. Products labeled as AOD9604 should not be assumed to have the same properties as hGH.
No. It is a synthetic peptide fragment modeled on part of human growth hormone, not the full hormone. It does not contain the complete sequence or receptor-binding regions of hGH.