If you have been reading about WADA prohibited list 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.
Last reviewed on 2026-03-13. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Detection and characterization of AOD-9604 in research and anti-doping settings typically rely on mass spectrometry coupled with liquid chromatography. These methods can identify the peptide by its mass and fragmentation pattern. Immunoassays may also be used in some screening contexts, but they can cross-react with related peptides. Because the molecule is small and may be present at low concentrations, sample preparation and method validation are important. Confirmatory analysis usually requires comparison with a certified reference standard.
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.
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.
| 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. |
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.
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.
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.
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.
GeneReviews/NCBI/NIH/UW entry on APC-Associated Polyposis Conditions OMIM entries on APC-Associated Polyposis Conditions[link removed] Adenomatous+Polyposis+Coli+Protein at the U.S. National Library of Medicine Medical Subject Headings (MeSH) GeneCard Database concerning peer-reviewed reports on cancer critical alteration in several genes including (APC (protein)), (TP53), (Beta-catenin|β-catenin) Human APC genome location and APC gene details page in the UCSC Genome Browser.
TMEM125 has two variant transcripts that differ only in the 5' untranslated region (UTR), but both encode the same protein. mRNA variant 1 represents the longer of the two variants and is 1898 base pairs (bp) in length; variant 2 is 1797 bp long. TMEM125 microarray-assessed expression patterns in normal human tissue demonstrate the primary tissues of expression are the pancreas, lungs, salivary glands, trachea, brain, prostate, spinal cord, and thyroid. Additionally, RNA-seq data illustrates transcript expression in the following additional tissue: colon, small intestines, prostate, and stomach. TMEM125 comprises 219 amino acids with four transmembrane domains. Its predicted isoelectric point is 8.32 and predicted molecular weight is 22.1 kDa. It is primarily leucine-rich, and secondarily alanine- and glycine-rich; TMEM125 is also arginine- and lysine-deficient. It has two core repeat blocks, VALL and TTSS, which both appear twice within the protein. The secondary structure of TMEM125 is predicted to consist of α-helices and small segments of β-sheets.
In both pharmacology and nutrition sciences, bioavailability is measured by calculating the area under curve (AUC) of the drug concentration time profile. Bioavailability is a term used to describe the percentage of an administered dose of a xenobiotic that reaches the systemic circulation unchanged. It is denoted by the letter f (or, if expressed in percent, by F). In nutritional science, which covers the intake of nutrients and non-drug dietary ingredients, the concept of bioavailability lacks the well-defined standards associated with the pharmaceutical industry. The pharmacological definition cannot apply to these substances because utilization and absorption is a function of the nutritional status and physiological state of the subject, resulting in even greater differences from individual to individual (inter-individual variation). Therefore, bioavailability for dietary supplements can be defined as the proportion of the administered substance capable of being absorbed and available for use or storage.
Sources: en.wikipedia.org
Most commonly 2,5-diketopiperazines are generated by cyclisation of dipeptides. In addition to the many methods of peptide synthesis, the Ugi reaction can be applied. Dipeptides with an ester terminus spontaneously cyclize often. Racemization can be problematic. The Ugi reaction using an isonitrile, amino acid, aldehyde and amine, can produce a dipeptide in equally high yield and optical purity, to that formed by standard peptide couplings. Commonly, an isonitrile is chosen to give a labile terminal amide to enable cyclization. For example, the direct 2,5-DKP ring formation via such an activated leaving group using the stable, easily accessible and versatile convertible isonitrile 1-isocyano-2-(2,2-dimethoxyethyl)-benzene 4 gave a one-pot synthesis of N-substituted 2,5-diketopiperazine's 7.
Enteroglucagon is a peptide hormone derived from preproglucagon. It is a gastrointestinal hormone, secreted from mucosal cells primarily of the colon and terminal ileum. It consists of 37 amino acids. Enteroglucagon is released when fats and glucose are present in the small intestine; which decrease the motility to allow sufficient time for these nutrients to be absorbed. In 1948, Sutherland and De Duve identified a gastrointestinal glucagon-like material in gastric mucosa, the term "enteroglucagon" was used to describe this material that shared a similar immunoreactivity with glucagon. A half-century later, Brubaker and Drucker studied proglucagon gene expression, they discovered the function of enteroglucagon is related to the growth of intestinal epithelium.
The final step in the non-mevalonate pathway is carried out by the enzyme 4-hydroxy-3-methylbut-2-enyl diphosphate reductase, which gives a mixture of dimethylallyl pyrophosphate and isopentenyl pyrophosphate in the ratio of five to one. The products are then used in terpenoid biosynthesis. HMB-PP is an essential metabolite in most pathogenic bacteria including Mycobacterium tuberculosis as well as in malaria parasites, but is absent from the human host. HMB-PP is the physiological activator ("phosphoantigen") for human Vγ9/Vδ2 T cells, the major γδ T cell population in peripheral blood. With a bioactivity of 0.1 nM it is 10,000-10,000,000 times more potent than any other natural compound, such as IPP or alkyl amines. HMB-PP functions in this capacity by binding the B30.2 domain of BTN3A1. 4-hydroxy-3-methylbut-2-enyl+pyrophosphate at the U.S. National Library of Medicine Medical Subject Headings (MeSH)
RANKL is a member of the TNF superfamily of ligands. Through binding to the RANK receptor it activates various molecules, like NF-kappa B, MAPK, NFAT and PI3K52. The RANKL/RANK signaling pathway regulates osteoclastogenesis, as well as, the survival and activation of osteoclasts. Adenosine is very relevant in bone metabolism, as it plays a role in formation and activation of both osteoclasts and osteoblasts. Adenosine acts by binding to purinergic receptors and influencing adenylyl cyclase activity and the formation of cAMP and PKA 54. Adenosine may have opposite effects on bone metabolism, because while certain purinergic receptors stimulate adenylyl cyclase activity, others have the opposite effect. Under certain circumstances adenosine stimulates bone destruction and in other situations it promotes bone formation, depending on the purinergic receptor that is being activated.
Sources: en.wikipedia.org
Receptors bind with endogenous ligands to produce a physiological effect and regulate the body and cellular homeostasis. In a ligand-receptor interaction, the ligand binds with the receptors to form a drug-receptor complex, producing a biological response. The biological nature of receptors can be enzymes, nucleic acids or cellular proteins. Common types of receptors include G-protein coupled receptors, nuclear receptors and ion channels. Functional antagonists would not produce a biological response after binding with a receptor. It blocks the binding of endogenous ligands to the receptors and thus inhibits the subsequent physiological effect.
Tuberculin, known in its modern form as purified protein derivative (PPD), is a combination of proteins that are used in the diagnosis of tuberculosis by injection into the skin. Common side effects include redness, itchiness (pruritus), and pain at the site of injection. Allergic reactions may occasionally occur. Use is safe in pregnancy. The original tuberculin, a glycerin extract of Mycobacterium tuberculosis, was discovered in 1890 by Robert Koch. Koch, best known for his work on the etiology (cause, origin) of tuberculosis (TB), laid down various rigorous guidelines that aided the establishment between a pathogen and the specific disease that followed that were later named Koch's postulates. Although he initially believed it would cure tuberculosis, this was later disproved. PPD was invented in 1934 by Florence B. Seibert, greatly improving the reliability of the skin test over Koch's extract. PPD is on the World Health Organization's List of Essential Medicines.
This detection method uses mammalian antibodies to bind to microbial toxins which can then be processed in a variety of different ways. Of the commercial ways of using immunochemical detection would be enzyme-linked immunosorbent assays (ELISA). This assay has the advantage of being able to screen for a broad range of toxins but could have issues with specificity depending on the antibody used. A more exotic setup involves the use of CdS quantum dots which are used in an electro-chemiluminescent immunosensor. A major aspect of immunochemical methods being tested in laboratories are uses of nanowires and other nanomaterials to detect microbial toxins.
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.
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.