A practical reference on hGH fragment: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-07-13. Anything still debated is marked as such rather than presented as settled.
Interest in AOD-9604 arose from attempts to separate metabolic effects from growth effects attributed to hGH. Early work explored whether the fragment could influence lipolysis or fat oxidation without promoting growth. Those questions remain partly unresolved because human data are limited and results have varied across studies. The peptide is not a hormone replacement for hGH and is not equivalent to hGH in clinical use. Its research history includes both laboratory studies and commercial marketing claims that are not the same as regulatory approval.
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.
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.
Regulatory interest in AOD-9604 increased after high-profile anti-doping cases involving peptide products. In some cases, the substance was supplied under alternative names or in compounded preparations, complicating traceability. Sports tribunals and anti-doping panels have discussed whether the peptide was explicitly banned at the time of use, leading to clarifications by the World Anti-Doping Agency. For consumers and researchers, the legal status can vary by jurisdiction, and products marketed as research chemicals may lack independent quality verification.
| 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. |
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.
Identity and purity are commonly checked with reversed-phase high-performance liquid chromatography and mass spectrometry. RP-HPLC separates the peptide from related impurities and can estimate purity by peak area. Mass spectrometry confirms molecular mass and helps detect sequence variants or truncations. Some laboratories use amino acid analysis or peptide mapping for additional characterization. No single method proves biological activity; these techniques establish chemical identity and purity only. They also require suitable reference standards for confident comparison.
Commercial AOD-9604 may vary in purity, counterion content, and residual moisture. Certificates of analysis often report HPLC purity, mass confirmation, and appearance, but testing methods differ between suppliers. Independent verification is sometimes used because labeled content may not match actual peptide amount. Stability under different pH and temperature conditions is not fully standardized across studies. Researchers generally treat lyophilized material as the reference form for weighing and reconstitution. Moisture content can affect accurate mass measurement.
The city of Moscow is led by a single mayor, Sergey Sobyanin. The city is divided into 12 administrative okrugs and 125 districts. Moscow's urban planning appeared as early as the 12th century, when the city was founded. The city center grew by amalgamating with suburbs, in keeping with medieval principles of urban development, as strong fortress walls gradually spread along the circular streets of adjacent new settlements. The first circular defense walls established the trajectory for Moscow's rings, laying the groundwork for future city planning. The following fortifications served as the city's circular defense boundaries at some point in history:
Katherine J. Franz (born 1972) is an American chemist. She is the chair of the department of chemistry at Duke University. She studies metal ion coordination in biological systems and looks to use the insight to manage species such as copper and iron. Franz was awarded the American Chemical Society Award for Encouraging Women into Careers in the Chemical Sciences.
== Other uses == Pregnancy tests may be used to predict if a pregnancy is likely to continue or is abnormal. Miscarriage, or spontaneous abortion or pregnancy loss, is common in early pregnancy. Serial quantitative blood tests may be done, usually 48 hours apart, and interpreted based on the knowledge that hCG in a viable normal pregnancy rises rapidly in early pregnancy. For example, for a starting hCG level of 1,500 mIU/ml or less, the hCG of continuing, normal pregnancy will increase at least 49% in 48 hours. However, for pregnancies with a higher starting hCG, between 1,500 and 3,000 mIU/ml, the hCG should rise at least 40%; for a starting hCG greater than 3,000 mIU/ml, the hCG should increase at least 33%. Failure to rise by these minimums may indicate that the pregnancy is not normal, either as a failed intrauterine pregnancy or a possible ectopic pregnancy. Ultrasound is also a common tool for determining viability and location of a pregnancy. Serial ultrasound may be used to identify non-viable pregnancies, as pregnancies that do not grow in size or develop expected structural findings on repeated ultrasounds over a 1–2 week interval may be identified as abnormal. Occasionally, a single ultrasound may be used to identify a pregnancy as non-viable; for example, an embryo that is greater than a certain size but that lacks a visible heart beat may be confidently determined to be not viable without the need for follow up ultrasound for confirmation.
=== Central nervous system === In general, adenosine has an inhibitory effect in the central nervous system (CNS). Caffeine's stimulatory effects are credited primarily (although not entirely) to its capacity to block adenosine receptors, thereby reducing the inhibitory tonus of adenosine in the CNS. This reduction in adenosine activity leads to increased activity of the neurotransmitters dopamine and glutamate. Experimental evidence suggests that adenosine and adenosine agonists can activate Trk receptor phosphorylation through a mechanism that requires the adenosine A2A receptor. Adenosine in the brain acts through three major receptor subtypes—A1, A2A, and A3—distributed across various neuronal and glial populations. Activation of neuronal A1 receptors generally exerts inhibitory effects, contributing to synaptic regulation. In a preclinical knock-in model of Alzheimer's disease, neuronal hyperexcitability during the asymptomatic stage has been shown to originate at the synaptic compartment and is associated with a deficient adenosinergic tone, suggesting that impaired adenosine signaling may contribute to early synaptic dysfunction.
Sources: en.wikipedia.org
) within a single experiment. It consists of two cells which are enclosed in an adiabatic jacket. The compounds to be studied are placed in the sample cell, while the other cell, the reference cell, is used as a control and contains the buffer in which the sample is dissolved. The technique quantifies the heat released or absorbed during the binding process by incrementally adding one reactant (via a syringe) to another (in the sample cell) while maintaining constant temperature and pressure. Heat-sensing devices within the ITC detect temperature variations between two cells, transmitting this information to heaters that adjust accordingly to restore thermal equilibrium between the cells. This energy is converted into binding enthalpy using the information about concentrations of the reactants and the cell volume. Compared to other calorimeters, ITC does not require any correctors since there is no heat exchange between the system and the environment. ITC is also highly sensitive with a fast response time and benefits from modest sample requirements. While differential scanning calorimetry (DSC) can also provide direct information about the thermodynamic of binding interactions, ITC offers the added capability of quantifying the thermodynamics of metal ion binding to proteins.
=== Cold case review === Every year on the anniversary of the killing, Scotland Yard came under pressure for progress. In the late 1990s, Nickell's murder was re-investigated as part of Operation Enigma, which was a national cross-force investigation into the unsolved murders of 207 women. Under new management, detectives began to collate evidence and files related to the case from 2000. In 2002, ten years after the killing, Scotland Yard used a cold case review team, which used refined DNA techniques only recently made available. A small team of officers and retired veteran investigators analysed statements from witnesses, reassessed files on a number of potential suspects and examined the possibility that the case was linked to other crimes. Officers compared the injuries suffered by Nickell with other attacks and consulted forensic scientists about improvements in DNA matching. In July 2003, reports surfaced that, after 18 months of tests on Nickell's clothes, police had found a male DNA sample which did not match her boyfriend or son. The sample at the time was insufficient to confirm an identity, but was large enough to rule out suspects.
On 12 January 2016, thirty-four past and present Essendon Football Club players – twelve of whom were still on the Essendon list – were suspended until November 2016 after being found guilty of being injected with the banned substance thymosin beta-4 during the 2012 season, significantly compromising Essendon's playing list for 2016. The club received permission to augment its list by recruiting up to ten top-up players from lower levels on contracts which would last until 31 October 2016. The club was limited to players who had been on an AFL list in either 2014 or 2015, with no more than one player to be taken from any state-level club; or, it could recruit any VFL-listed player from its own reserves team without restriction.
== External links == DoD/FDA Shelf Life Extension Program SLEP - The DOD/FDA Shelf Life Extension Program SLEP information paper Other studies In vitro dissolution of expired antibiotics (Amoxicillin / Ampicillin / Doxycycline) Stockpiled Antivirals at or Nearing Expiration (Tamiflu / Relenza) Investigative Report: Do Antibiotic Expiration Dates Matter?
It has been suggested that the RNA world may have been preceded by an "RNA-like world" where other nucleic acids with a different backbone, such as GNA, PNA, and TNA existed, however, evidence for this hypothesis been called "tenuous".
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.
Yes, the World Anti-Doping Agency classifies AOD-9604 as a prohibited peptide hormone and related substance. Its use by athletes is banned under the relevant anti-doping code.