The short version of peptide hormone fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-02-23 and is reviewed periodically as new material appears.
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.
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.
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.
Clinical development of AOD-9604 included trials in people with obesity. Reports from early-phase and mid-phase studies described modest or inconsistent changes in body weight. A phase IIb program did not meet its primary endpoint, and the compound was not approved for medical use. Differences in formulation, delivery route, and participant characteristics may explain some of the variation. Later investigations explored whether the peptide might have effects in other tissues, including cartilage.
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.
| 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. |
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.
Research interest in AOD-9604 often focuses on whether it can influence lipid metabolism without the growth-promoting or glucose-related effects of full-length hGH. This question remains unresolved, and findings depend on model, dose, and measurement method. Some reviews treat the peptide as a historical obesity candidate rather than an active therapeutic. Others cite it in discussions of peptide fragments, metabolic signaling, and performance-enhancing substances. Clear conclusions are limited by the small number of rigorous, independent human studies.
AOD9604 is commonly supplied as a white to off-white lyophilized powder. The powder is typically stored at -20 °C or below, protected from light and moisture, because peptides can degrade through oxidation, hydrolysis, or aggregation. If it is reconstituted for laboratory use, an appropriate aqueous buffer or solvent is chosen, and the solution is kept cold and handled to avoid repeated freeze-thaw cycles. These practices support stability but do not imply suitability for human use.
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.
== Reactions == Anthranilic acid can be diazotized to give the diazonium cation [C6H4(CO2H)(N2)]+. This cation can be used to generate benzyne, dimerized to give diphenic acid, or undergo diazonium coupling reactions such as in the synthesis of methyl red. It reacts with phosgene to give isatoic anhydride, a versatile reagent. Chlorination of anthranilic acid gives the 2,4-dichloro derivative, which can undergo reductive coupling to form a biaryl compound.
== Occurrence == Chymosin is found in a wide range of tetrapods, although it is best known to be produced by ruminant animals in the lining of the abomasum. Chymosin is produced by gastric chief cells in newborn mammals to curdle the milk they ingest, allowing a longer residence in the bowels and better absorption. Non-ruminant species that produce chymosin include pigs, cats, seals, and chicks. One study reported finding a chymosin-like enzyme in some human infants, but others have failed to replicate this finding. Humans have a pseudogene for chymosin that does not generate a protein, found on chromosome 1. Humans have other proteins to digest milk, such as pepsin and lipase. In addition to the primate lineage leading up to humans, some other mammals have also lost the chymosin gene.
In the most expensive political campaign in Vermont's history, Sanders defeated businessman Rich Tarrant by an almost 2-to-1 margin. Many national media outlets projected him as the winner just after the polls closed, before any returns came in.
Sources: en.wikipedia.org
cells derived from Fyn-/- mice (as well as cells derived from Fyn, Src, Yes, Fyn triple knockout mice (SYF)); a kinase-inactive, dominant negative mutant form of Fyn (K299M); pharmacologic inhibitors of Src family kinases, such as PP2; note that PP2 also inhibits other tyrosine protein kinases such as Abl, PDGFR and c-Kit. Using these tools, a requirement for Fyn has been shown for the following signaling pathways: T and B cell receptor signaling, integrin-mediated signaling, growth factor and cytokine receptor signaling, platelet activation, ion channel function, cell adhesion, axon guidance, fertilization, entry into mitosis, and differentiation of natural killer cells, oligodendrocytes and keratinocytes. Fyn also has an important role to play in TLR-mediated immune responses from T cells.
White was married to his wife Edna for more than 40 years. He died unexpectedly on February 14, 1980, in Santa Barbara, California, where he had gone that day from his home in Palo Alto to deliver a lecture at the University of California. Several awards in the field of biochemistry have been named for White, including at Oakland University in Michigan, Wayne State University, George Washington University School of Medicine and the Gladstone Institutes. 1935 – Traveling Fellowship, American Physiological Society, for the XVth International Congress of Physiology (Leningrad and Moscow) 1938 – Eli Lilly Prize in Biochemistry 1960 – Distinguished Alumni Award, University of Denver 1967 – Sesquicentennial Alumni Award, University of Michigan 1969 – Borden Award, Association of American Medical Colleges 1959 – Doctor of Humane Letters, Yeshiva University 1975 – Doctor of Science, University of Denver
=== Subsequent developments === It was also realized that the beta decay of 239Np must produce an isotope of element 94 (now called plutonium), but the quantities involved in McMillan and Abelson's original experiment were too small to isolate and identify plutonium along with neptunium. The discovery of plutonium had to wait until the end of 1940, when Glenn T. Seaborg and his team identified the isotope plutonium-238. In 1942, Hahn and Fritz Strassmann, and independently Kurt Starke, reported the confirmation of element 93 in Berlin. Hahn's group did not pursue element 94, likely because they were discouraged by McMillan and Abelson's lack of success in isolating it. Since they had access to the stronger cyclotron at Paris at this point, Hahn's group would likely have been able to detect element 94 had they tried, albeit in tiny quantities (a few becquerels). Neptunium's unique radioactive characteristics allowed it to be traced as it moved through various compounds in chemical reactions, at first this was the only method available to prove that its chemistry was different from other elements. As the first isotope of neptunium to be discovered has such a short half-life, McMillan and Abelson were unable to prepare a sample that was large enough to perform chemical analysis of the new element using the technology that was then available. However, after the discovery of the long-lived 237Np isotope in 1942 by Glenn Seaborg and Arthur Wahl, forming weighable amounts of neptunium became a realistic endeavor.
Sources: en.wikipedia.org
== Guideline versions == GMP is enforced in the United States by the U.S. Food and Drug Administration (FDA), under Title 21 CFR. The regulations use the phrase "current good manufacturing practices" (CGMP) to describe these guidelines. Courts may theoretically hold that a product is adulterated even if there is no specific regulatory requirement that was violated as long as the process was not performed according to industry standards. However, since June 2007, a different set of CGMP requirements have applied to all manufacturers of dietary supplements, with additional supporting guidance issued in 2010. Additionally, in the U.S., medical device manufacturers must follow what are called "quality system regulations" which are deliberately harmonized with ISO requirements, not necessarily CGMPs. The World Health Organization (WHO) version of GMP is used by pharmaceutical regulators and the pharmaceutical industry in over 100 countries worldwide, primarily in the developing world. The European Union's GMP (EU GMP) enforces similar requirements to WHO GMP, as does the FDA's version in the US. Similar GMPs are used in other countries, with Australia, Canada, Japan, Saudi Arabia, Singapore, Philippines], Vietnam and others having highly developed/sophisticated GMP requirements. In the United Kingdom, the Medicines Act (1968) covers most aspects of GMP in what is commonly referred to as "The Orange Guide," which is named so because of the color of its cover; it is officially known as Rules and Guidance for Pharmaceutical Manufacturers and Distributors.
=== Other dipeptides === Homoanserine (N-(4-aminobutyryl)-L-histidine) is another dipeptide identified in the brain and muscles of mammals. Kyotorphin (L-tyrosyl-L-arginine) is a neuroactive dipeptide which plays a role in pain regulation in the brain. Balenine (or ophidine) (beta-alanyl-N tau-methyl histidine) has been identified in the muscles of several species of mammal (including man), and the chicken. Glorin (N-propionyl-γ-L-glutamyl-L-ornithine-δ-lac ethyl ester) is a chemotactic dipeptide for the slime mold Polysphondylium violaceum. Barettin (cyclo-[(6-bromo-8-en-tryptophan)-arginine]) is a cyclic dipeptide from the marine sponge Geodia barretti. Dialanine is commonly used as a model in molecular dynamics. Xenortides, isolated from the bacterium Xenorhabdus nematophila Oglufanide (H-L-Glu-Trp-OH, also known as Thymogen), immunomodulator researched for conditions including Hepatitis C.
In a survey of US laypersons in December 2021, most people believed the scientifically supported idea that trained bystanders can reverse overdoses with naloxone. A survey of US naloxone prescription programs in 2010 revealed that 21 out of 48 programs reported challenges in obtaining naloxone in the months leading up to the survey, due mainly to either cost increases that outstripped allocated funding or the suppliers' inability to fill orders. The approximate cost of a 1 ml ampoule of naloxone in the US is estimated to be significantly higher than in most other countries. Take-home naloxone programs for people who use opioids are underway in many North American cities. CDC estimates that the US programs for drug users and their caregivers prescribing take-home doses of naloxone and training on its use prevented 10,000 opioid overdose deaths by 2014. In Australia, some forms of naloxone are available "over the counter" in pharmacies free without a prescription under the Take Home Naloxone programme. It comes in single-use filled syringe form similar to law enforcement kits as well as nasal sprays. In 2024, those with a prescription can purchase five doses for around AU$32 or just over AU$6 per dose. In Alberta, in addition to pharmacy distribution, take-home naloxone kits are available and distributed in most drug treatment or rehabilitation centers. In the European Union, take home naloxone pilots were launched in the Channel Islands and in Berlin in the late 1990s.
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.
No. Major drug regulators have not approved AOD-9604 for weight loss or any other therapeutic indication. It remains an investigational compound studied in research settings.