If you have been reading about regulatory status 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.
Updated 2026-04-18. Numbers and descriptions here follow the published literature rather than marketing material.
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 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 |
|---|---|---|
| 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. |
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.
AOD9604 is a synthetic peptide modeled on the C-terminal region of human growth hormone. It corresponds to a short sequence near the end of the 191-amino-acid hormone, often described as residues 176–191 or a related fragment. Researchers designed it to separate metabolic effects from the growth-promoting actions of full-length growth hormone. Early work in the 1990s explored it as a candidate for weight and lipid disorders. It is not a naturally circulating hormone fragment produced in large amounts.
Laboratory studies have reported that AOD9604 can increase lipolysis and reduce lipid accumulation in fat cells. The precise molecular target remains uncertain, and the compound does not appear to activate the growth hormone receptor in the same way as full-length hGH. Proposed mechanisms include effects on beta-adrenergic signaling and enzymes involved in fatty acid synthesis, but these pathways are not firmly established. Because most evidence comes from cell and animal models, whether the same effects occur in humans is an open question.
Clinical development of AOD9604 included trials in people with obesity, but the results did not lead to approval as a prescription medicine in major markets. Interest later shifted to research settings and to unapproved products marketed for body composition. Regulatory agencies have questioned whether the peptide qualifies as a dietary ingredient, and some have issued warnings about its presence in supplements. Long-term human safety data are limited, and questions about efficacy, dosing, and target populations remain unresolved.
== History == BioDuro was founded in 1996 in the United States as a drug discovery services company. In 2009, it was acquired by Pharmaceutical Product Development (PPD), a leading global contract research organization. In 2020, Advent International merged BioDuro with the China-based CRO Sundia to form BioDuro-Sundia, creating a combined CRDMO serving biotech and pharma clients globally. In 2021, the company expanded its U.S. operations in Irvine to support clinical and commercial drug product manufacturing. In 2025, BioDuro announced new investments in China, including a Bengbu process development and scale-up site and an OEB-5 high-potency laboratory for ADC payloads and HPAPIs.
== Pathophysiology == Dupuytren’s contracture is a fibroproliferative disorder of the palmar fascia in which abnormal activation of fibroblasts and myofibroblasts, driven by mediators such as transforming growth factor-beta, platelet-derived growth factor, epidermal growth factor, interleukin-1 beta, and connective tissue growth factor, leads to excess deposition of type III collagen and progressive remodeling of fascial tissue. Studies have suggested that intracellular signaling, as opposed to paracrine or endocrine signaling, may be the strongest driver of abnormal fibroblast activity in most cases of Dupuytren's contracture. The disease typically evolves through a proliferative stage marked by cellular nodules rich in immature fibroblasts and myofibroblasts, an involution stage in which these cells align along longitudinal stress lines in the hand, and a residual stage in which dense, relatively hypocellular collagenous cords persist and mechanically flex the digits. As normal fascial structures are converted into pathologic cords, characteristic deformities emerge: central cords commonly produce skin puckering and metacarpophalangeal contracture, natatory cords (developed from the natatory ligament) narrow the web spaces, and spiral cords can cause proximal interphalangeal contracture while displacing the digital neurovascular bundle.
=== Bone morphogenetic proteins === Key growth factors in endochondral skeletal differentiation include bone morphogenetic proteins (BMPs) that determine to a major extent where chondrocyte differentiation occurs and where spaces are left between bones. The system of cartilage replacement by bone has a complex regulatory system. BMP2 also regulates early skeletal patterning. Transforming growth factor beta (TGF-β), is part of a superfamily of proteins that include BMPs, which possess common signaling elements in the TGF beta signaling pathway. TGF-β is particularly important in cartilage differentiation, which generally precedes bone formation for endochondral ossification. An additional family of essential regulatory factors is the fibroblast growth factors (FGFs) that determine where skeletal elements occur in relation to the skin
Sources: en.wikipedia.org
In January 2024, the US and UK imposed sanctions on key Houthi figures, including the defense minister, in response to the Houthi attacks on international shipping in the Red Sea that escalated in November 2023. The new sanctions were imposed in addition to the existing sanctions against 11 Houthi individuals and 2 entities, which remained in force. On 28 April 2025, the U.S. Treasury Department sanctioned three shipping companies for their role in delivering oil products to the Houthis. The deliveries took place via the Houthi-controlled port of Ras Isa. On 8 April 2026, Costa Rica designated the Houthis as a terrorist organization.
Clinical trials involving new drugs are commonly classified into five phases. Each phase of the drug approval process is treated as a separate clinical trial. The drug development process will normally proceed through phases I–IV over many years, frequently involving a decade or longer. If the drug successfully passes through phases I, II, and III, it will usually be approved by the national regulatory authority for use in the general population. Phase IV trials are performed after the newly approved drug, diagnostic or device is marketed, providing assessment about risks, benefits, or best uses.
Enzyme structures may also contain allosteric sites where the binding of a small molecule causes a conformational change that increases or decreases activity. A small number of RNA-based biological catalysts called ribozymes exist, which again can act alone or in complex with proteins. The most common of these is the ribosome which is a complex of protein and catalytic RNA components.
==== Germany ==== The drug is in Appendix III of the Narcotics Act (Betäubungsmittelgesetz or BtMG). The law allows only physicians, dentists, and veterinarians to prescribe oxycodone and the federal government to regulate the prescriptions (e.g., by requiring reporting).
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.
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.