This is a working overview of peptide hormone, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-02-06 and is reviewed periodically as new material appears.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized form; visual inspection |
| Solubility | Soluble in water and aqueous buffers | Depends on pH, purity, and counterion |
| Typical storage | -20 °C or below, desiccated | Protect from light; avoid repeated freeze-thaw after reconstitution |
| Common analytical method | Reversed-phase HPLC and mass spectrometry | Purity by HPLC; identity and mass by LC-MS or MALDI-TOF |
| Common synonyms | hGH fragment 176–191; AOD-9604 | Names vary in research and product labeling |
platelet-derived growth factor transforming growth factor beta fibroblast growth factor insulin-like growth factor 1 insulin-like growth factor 2 vascular endothelial growth factor A vascular endothelial growth factor C epidermal growth factor interleukin 8 keratinocyte growth factor connective tissue growth factor hepatocyte growth factor stromal cell-derived factor 1 endostatin
== Death == On February 21, 1961, Jones died of lung cancer at age 67 in Minneapolis, Minnesota, predeceasing his wife, Lucille. In an obituary in the Saturday Evening Post, it was said, "Most engineers start at the bottom of a project and work up, but Fred takes a flying leap to the top of the mountain and then backs down, cutting steps for himself and the rest of us as he goes." Jones continued filing for patents almost up until his death, receiving his last patent in February 1960.
Unpressed bittern-gelled soft tofu is called sun-dubu (순두부; "mild tofu") in Korean. Soy milk is mixed with seawater, or saline water made with sea salt, so that it curdles. The curds remain loose and soft. Freshly made sun-dubu is eaten boiled with little or no seasoning. Manufactured sundubu is usually sold in tubes. It is also the main ingredient in sundubu-jjigae (순두부찌개; "soft tofu stew"). Although the word sun in sun-dubu does not have a Sino-Korean origin, sun-dubu is often translated into Chinese and Japanese using the Chinese character 純, whose Korean pronunciation is sun and the meaning is "pure". Thus in China, sun-dubu is called chún dòufu (純豆腐; "pure tofu"), and in Japan, it is called jun-tōfu (純豆腐) or sundubu (スンドゥブ).
== Views == In his autobiography, Scottish commentator Bill McLaren wrote in 1991: "It has been a disgrace that a World Rugby Union power has been eliminated from world competition for all those years, even allowing for their country's unacceptable racist policy." Ian Robertson documented how the Springboks' position slowly deteriorated over the decades, but suggested that the fault lay outside the rugby fraternity:
Sources: en.wikipedia.org
== Further reading == Zhu KW (2023). "Efficacy and safety evaluation of Azvudine in the prospective treatment of COVID-19 based on four phase III clinical trials". Frontiers in Pharmacology. 14 1228548. doi:10.3389/fphar.2023.1228548. PMC 10484631. PMID 37693894.
=== Alternative concepts === During their research, Eigen and Schuster also considered types of protein and nucleotide coupling other than hypercycles. One such alternative was a model with one replicase that performed polymerase functionality and that was a translational product of one of the RNA matrices existing among the quasispecies. This RNA-dependent RNA polymerase catalysed the replication of sequences that had specific motifs recognized by this replicase. The other RNA matrices, or just one of their strands, provided translational products which had specific anticodons and were responsible for unique assignment and transportation of amino acids. Another concept devised by Eigen and Schuster was a model in which each RNA template's replication was catalysed by its own translational product; at the same time, this RNA template performed a transport function for one amino acid type. Existence of more than one such RNA template could make translation possible. Nevertheless, in both alternative concepts, the system will not survive due to the internal competition among its constituents. Even if none of the constituents of such a system is selectively favoured, which potentially allows coexistence of all of the coupled molecules, they are not able to coevolve and optimize their properties. In consequence, the system loses its internal stability and cannot live on. The reason for inability to survive is the lack of mutual control of constituent abundances.
== History == Repligen was founded in 1981 by Alexander Rich and Paul Schimmel and was incorporated in Delaware. It has a headquarters and manufacturing facility in Waltham, Massachusetts. In 2008, an agreement was struck to divest certain intellectual property rights to Bristol-Myers Squibb around the drug Orencia in exchange for ongoing royalty payments through the end of 2013. In 2011, Repligen acquired bioproduction assets from Novozymes, which doubled the company's bioprocessing capabilities. Before 2012, Repligen maintained dual capabilities in developing pharmaceutical therapeutics (drug discovery and development) and the development of materials supporting biological drug manufacture (bioprocessing business). A decision was made in 2012 to focus on the bioprocessing business and reduce research and development expenditures. Development of an imaging agent, designated RG1068, based on a synthetic human hormone was halted in 2012 following a request by the FDA for additional safety and efficacy data beyond that provided in a New Drug Application submission; a marketing authorisation application had been submitted in parallel to the EMA. At the end of 2012, Repligen out-licensed its spinal muscular atrophy program, in particular the small molecule candidate drug RG3039, to Pfizer. This divestment included licensing rights to two patents to Pfizer.
These facts spurred Pat Farrell, wife of the inventor of Cryo-branding, to create the Alpha-Angle Freeze Mark in the early 1970s. Her goal was a set of symbols that could produce unique brands, remained legible for longer than alphanumeric brands, could not easily be tampered with, and reduced the number of branding irons that must be carried into the field. The Alpha-Angle Freeze Mark is composed of symbols representing 46 US States and the Federal Government as well as 20 breeds of horse. To complement these symbols Farrell also invented a number system requiring only two signs. In this number system, the numerals 0 through 9 can be produced using two brands. One is shaped like a right angle (∟ ) and the other is like parallel lines (ll ). Different numerals are created depending on the orientation of these two symbols. For example, vertical parallel lines (ll ) stand for 1 and horizontal lines (=) for zero. The other eight digits are created by rotating the ∟-shaped brand clockwise through 360º. Using only these two brands, the Alpha-Angle Freeze Mark system can encode any sequence of numbers. This was a great improvement on traditional numerals requiring 10 separate irons, each of which must be applied either one after the other or simultaneously with an assistant. The easiest way to remember the code is to think of the even numbers as making a square and the odd numbers, a diamond. Superimposing the diamond onto the square gives the full series of 2–9, which can be easily counted in the mind by starting with 2 in the top left-hand corner of the square.
== Procedure == Two types of clamp are quite commonly used. The hyperglycemic clamp, which requires maintaining a high blood sugar level by perfusion or infusion with glucose, is a way to quantify how fast beta-cells respond to glucose. The hyperinsulinemic clamp, which requires maintaining a high insulin level by perfusion or infusion with insulin, is a way to quantify how sensitive the tissue is to insulin. The hyperinsulinemic clamp is also called euglycemic clamp, meaning a normal blood sugar level is maintained. Hyperglycemic clamp technique: The plasma glucose concentration is acutely raised to 125 mg/dl above basal levels by a continuous infusion of glucose. This hyperglycemic plateau is maintained by adjustment of a variable glucose infusion, based on the rate of insulin secretion and glucose metabolism. Because the plasma glucose concentration is held constant, the glucose infusion rate is an index of insulin secretion and glucose metabolism. The hyperglycemic clamps are often used to assess insulin secretion capacity. Hyperinsulinemic-euglycemic clamp technique: The plasma insulin concentration is acutely raised and maintained at 100 μU/ml by a continuous infusion of insulin. Meanwhile, the plasma glucose concentration is held constant at basal levels by a variable glucose infusion. When the steady-state is achieved, the glucose infusion rate equals glucose uptake by all the tissues in the body and is therefore a measure of tissue insulin sensitivity. The hyperinsulinemic clamps are often used to measure insulin resistance.
Sources: en.wikipedia.org
Lyophilized AOD9604 is generally kept at -20 °C or colder, desiccated, and protected from light. Reconstituted solutions are usually refrigerated and handled to minimize repeated freeze-thaw cycles. These are general laboratory handling practices, not instructions for human use.
Mass spectrometry, such as LC-MS or MALDI-TOF, confirms the molecular mass and can reveal sequence-related impurities. Reversed-phase HPLC is used for purity, and peptide mapping or amino acid analysis can support sequence identity. No single method establishes every quality attribute.
No. AOD9604 is a short synthetic fragment of the hGH sequence, not the full 191-amino-acid hormone. It lacks the regions that mediate hGH receptor activation and growth-promoting effects. Products labeled as AOD9604 should not be assumed to have the same properties as hGH.
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.