The short version of anti-doping fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-01-11 and is reviewed periodically as new material appears.
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.
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.
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.
Early interest in AOD-9604 centered on whether a fragment of human growth hormone could influence fat metabolism without the broader effects of the full hormone. Cell and animal studies reported changes in fat storage and breakdown. Human trials followed, but the results were not strong enough to secure regulatory approval. The compound remains available for laboratory research, and its clinical potential is still described as uncertain. Studies continue to examine its activity and safety profile.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized form |
| Solubility | Soluble in water | Also soluble in aqueous buffers |
| Storage temperature | -20°C or below | Protect from light and moisture |
| Analytical method | RP-HPLC | Purity and identity assessment |
| Mass confirmation | Mass spectrometry | Verifies molecular mass |
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.
Development of AOD-9604 began in the 1990s as scientists sought to isolate metabolic effects of growth hormone without its growth-promoting actions. Early laboratory work focused on fat cells and animal models. Several human trials followed, examining changes in body composition and fat mass. Results have been mixed, and the peptide has not progressed to widespread clinical approval. Interest continues in research settings, particularly regarding its mechanism and potential metabolic targets.
Regulatory status varies by country. In the United States, AOD-9604 is not approved as a prescription drug. It is sometimes sold as a research chemical or dietary supplement, though such marketing may fall outside legal frameworks. The World Anti-Doping Agency prohibits its use in sport. Researchers must obtain it through legitimate suppliers and follow institutional rules. Its legal classification continues to evolve as authorities increasingly assess peptide products more broadly.
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.
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.
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.
Complement component 1s (EC 3.4.21.42, C1 esterase, activated complement C1s, complement C overbar 1r, C1s) is a protein involved in the complement system. C1s is part of the C1 complex. In humans, it is encoded by the C1S gene. C1s cleaves C4 and C2, which eventually leads to the production of the classical pathway C3-convertase.
The periodic table is a graphic description of the periodic law, which states that the properties and atomic structures of the chemical elements are a periodic function of their atomic number. Elements are placed in the periodic table according to their electron configurations, the periodic recurrences of which explain the trends in properties across the periodic table. An electron can be thought of as inhabiting an atomic orbital, which characterizes the probability it can be found in any particular region around the atom. Their energies are quantised, which is to say that they can only take discrete values. Furthermore, electrons obey the Pauli exclusion principle: different electrons must always be in different states. This allows classification of the possible states an electron can take in various energy levels known as shells, divided into individual subshells, which each contain one or more orbitals. Each orbital can contain up to two electrons: they are distinguished by a quantity known as spin, conventionally labelled "up" or "down". In a cold atom (one in its ground state), electrons arrange themselves in such a way that the total energy they have is minimized by occupying the lowest-energy orbitals available. Only the outermost electrons (valence electrons) have enough energy to break free of the nucleus and participate in chemical reactions with other atoms. The others are called core electrons.
== Lifestyle protective factors == Exercise and caffeine consumption are known to help decrease the risks of PD. Diet can also affect the level of risk: eating patterns rich in fruits, vegetables, whole grains, and fish, are associated with reduced risk of Parkinson's disease, while diets high in red meats and processed foods are associated with increased risk.
Sources: en.wikipedia.org
=== Fentanyl === Fentanyl is a synthetic piperidine opioid structurally similar to arylpiperidines. It is a strong μ-receptor agonist that is 80–100 times more potent than morphine, and has a fast onset with a shorter duration of action than morphine due to redistribution from CNS location to fatty tissue. When it is used as a continual drug (e.g. transdermal patches, longer term use of IV fentanyl in ICU patients) its elimination half-life and duration of effect are longer than morphine. It is metabolized in the liver by CYP3A4 enzymes to the compound norfentanyl.
== Mechanism of action == PAMORAs act by inhibiting the binding of opioids agonist to the μ-opioid receptor (MOR). The objective of PAMORAs treatment is to restore the enteric nervous system function (ENS). The MOR is found in several places in the body and PAMORAs is a competitive antagonist for binding to the receptor. The MORs in the gastrointestinal tract are the main receptors that PAMORAs are intended to block and prevent the binding of opioid agonists. PAMORAs are used in the treatment of opioid-induced bowel dysfunction (OIBD), a potential adverse effect caused by chronic opioid use. PAMORAs act on the three pathophysiological mechanisms of this adverse effect. They act on gut motility, gut secretion and sphincter function. PAMORAs effect on gut motility is that it can increase the resting tone in the circular muscle layer. The antagonist enhances the effect on tonic inhibition of the muscle tone. This will normalize the tone in the circular muscle layer and therefore prevent opioid-induced rhythmic contractions. When these two factors are combined, it results in decreased transit time. Impliedly these effects will decrease the passive absorption of fluids which helps with decreasing OIBD symptoms such as constipation, gut spasm and abdominal cramp. PAMORAs effect on gut secretion will help reverse the decreased cAMP formation that opioid agonists induce. Also, the antagonist will establish a normal secretion of chloride.
A liver biopsy (tissue examination) is the only test widely accepted (gold standard) as definitively diagnosing and distinguishing MASLD and MASH from other forms of liver disease. It can be used to assess the severity of inflammation and resultant fibrosis. However, since most people affected by MASLD are likely to be asymptomatic, liver biopsy presents too high a risk for routine diagnosis, so other methods are preferred, such as liver ultrasonography or liver MRI. For young people, guidelines recommend liver ultrasonography, but biopsy remains the best evidence. Liver biopsy is also the gold standard to detect hepatic fibrosis and assess its progression. Routine liver function blood tests are not sensitive enough to detect MASLD, and biopsy is the only procedure that can reliably differentiate MASLD from MASH. There are several liver biopsy techniques available to obtain liver tissue. Percutaneous liver biopsy remains the most common practice. Biopsies can also be performed via the transvenous route, either during surgery or by laparoscopy, especially for people with contraindications to a percutaneous approach. The liver biopsy can also be image-guided, in real-time or not, which is recommended for some clinical situations, such as people with known liver lesions, previous intra-abdominal surgery who may have adhesions, a small liver that is difficult to percuss, people with obesity, and people with evident ascites.
Sources: en.wikipedia.org
Reversed-phase HPLC is used to assess purity, and mass spectrometry confirms molecular mass. Amino acid analysis can verify composition. These methods are standard for peptide characterization.
Lyophilized powder should be stored at -20°C or lower, protected from light and moisture. Reconstituted solutions are less stable and should be aliquoted to avoid freeze-thaw cycles. Always follow supplier instructions.
Variability in purity, counterion content, and residual solvents is possible. Independent testing and certificates of analysis help verify quality. Microbial contamination can occur if handling is not sterile.
AOD-9604 is a synthetic peptide fragment of human growth hormone. It corresponds to the C-terminal region known as hGH 176-191 and is studied for metabolic effects. It is not an approved therapeutic drug.