A practical reference on AOD-9604: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
This page was last updated on 2025-10-24 and is reviewed periodically as new material appears.
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.
Proposed mechanism focuses on lipolysis, the breakdown of stored triglycerides into free fatty acids and glycerol. AOD-9604 is thought to act on adipose tissue without stimulating appetite or affecting blood sugar in the same way as growth hormone. Laboratory studies report increased fat oxidation in some models. The precise receptor interactions and signaling pathways remain incompletely characterized. Researchers have proposed that the peptide may influence fat mobilization through pathways distinct from the full hormone.
Research has examined whether the peptide affects fat mass independently of growth hormone's other actions. Early animal studies suggested reductions in body fat, but species differences and small sample sizes limit interpretation. Human studies have generally been short and have not consistently shown large effects. Some trials measured body composition, lipid profiles, and safety parameters, but the overall picture is one of suggestive yet inconclusive metabolic activity. Findings vary across study populations and protocols.
| 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. |
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.
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.
Dipeptidyl peptidase-4 inhibitors (DPP-4 inhibitors) are enzyme inhibitors that inhibit the enzyme dipeptidyl peptidase-4 (DPP-4). They are used in the treatment of type 2 diabetes mellitus. Inhibition of the DPP-4 enzyme prolongs and enhances the activity of incretins that play an important role in insulin secretion and blood glucose control regulation. Type 2 diabetes mellitus is a chronic metabolic disease that results from inability of the β-cells in the pancreas to secrete sufficient amounts of insulin to meet the body's needs. Insulin resistance and increased hepatic glucose production can also play a role by increasing the body's demand for insulin. Current treatments, other than insulin supplementation, are sometimes not sufficient to achieve control and may cause undesirable side effects, such as weight gain and hypoglycemia. In recent years, new drugs have been developed, based on continuing research into the mechanism of insulin production and regulation of the metabolism of sugar in the body. The enzyme DPP-4 has been found to play a significant role.
== Natural occurrence == An impure copper salt of the acid, with the formula Cu(C3N3O3H2)2(NH3)2, is currently the only known isocyanurate mineral, called joanneumite. It was found in a guano deposit in Chile. It is very rare.
=== Notable cases === As of April 2016, six hyperthymesia cases have been confirmed in peer-reviewed articles, the first being that of Jill Price (initially anonymised as "AJ") in 2006. More cases had been identified by 2012, but are yet to be published. Price's case was originally reported by researchers from the University of California, Irvine, Elizabeth Parker, Larry Cahill and James McGaugh, and is credited as being the first documented case of hyperthymesia. Price can apparently recall every day of her life from when she was 14 years old: "Starting on February 5, 1980, I remember everything. That was a Tuesday." In March 2009, Price was interviewed for an article in Wired magazine by Gary Marcus, a cognitive psychologist at New York University. Price's brain had been subject to a brain scan and the hippocampus and prefrontal cortex had been reportedly normal. Marcus claimed, however, that her brain resembled "those of people with obsessive-compulsive disorder" and suggested that her remarkable memory might be "the byproduct of obsession", claiming also that "the memory woman clings tightly to her past". Price strongly disputed this and McGaugh has also challenged the explanation. Price gave her first interview in over a year for the UK's Channel 4 documentary The Boy Who Can't Forget, and spoke of the challenges of living with the condition. K.
Sources: en.wikipedia.org
Charles Edward Moody, Deputy Chief Executive, Engineering and Marine Training Authority. For services to Training. Derek William Charles Morgan. For public service in Wales. Patricia Morris. For political service. John Robin Mulholland, Agricultural Estates Manager, Crown Estate Commissioners. Herbert Neville Nahapiet, Chief Executive, UK Detention Services. For services to Engineering and to the Construction Industry. Robert Livingston Nelson, Director, Dounreay, UKAEA. For services to the Nuclear Industry. Malcolm Terence Newman, Range E, Her Majesty's Treasury Joan Mary North. For political and public service Jean Nugent, Nursing Director, St. Helier Hospital, Carshalton, Surrey. For services to Health Care. Geoffrey James Osborne, lately Grade 7, Department of the Environment. Alfred David Owen, Trustee, Community Development Foundation. For services to the community in the West Midlands. Anthony Frederick Parker, lately Courts Administrator, Lord Chancellor's Department. Pamela Margaret Parker, Vice President, All England Women's Hockey Association. For services to Hockey. Alan Edward Parkinson, Officer in Charge, Board of Inland Revenue. David Romer Paton. For services to the community in Aberdeen. Professor Christopher Charles Payne, Chief Executive, Horticulture Research International. For services to Horticultural Research. Ann Philippa Pearce (Mrs Christie), Author. For services to Children's Literature. Anne Pegington, Secretary, Royal College of Nursing's Welsh Board. For services to Nursing in Wales. Howard Wesley Petch, Principal, Bishop Burton College.
== Composition == Salcatonin is composed of 32 amino acids, of which 13 differ from human calcitonin. The structure of human calcitonin and salcatonin is as follows: Human calcitonin: H-Cys1-Gly-Asn-Leu-Ser-Thr-Cys7-Met-Leu-Gly-Thr-Tyr-Thr-Gln-Asp-Phe-Asn-Lys-Phe-His-Thr-Phe-Pro-Gln-Thr-Ala-lle-Gly-Val-Gly-Ala-Pro-NH2 Salcatonin: H-Cys1-Ser-Asn-Leu-Ser-Thr-Cys7-Val-Leu-Gly-Lys-Leu-Ser-Gln-Glu-Leu-His-Lys-Leu-Gln-Thr-Tyr-Pro-Arg-Thr-Asn-Thr-Gly-Ser-Gly-Thr-Pro-NH2 The cysteine in the first and seventh positions form a disulfide bond.
=== Before 1873 === Prior to Japan adopting the Gregorian calendar, it used the lunisolar Japanese calendar. The first five years of the era correspond to the following date ranges in the Gregorian calendar:
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.
It is proposed to promote lipolysis in fat tissue, the breakdown of stored fat into fatty acids and glycerol. The detailed receptor and signaling mechanisms are not fully established.