If you have been reading about lipolysis 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 2026-08-01. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Typical storage temperature | -20 °C | Lyophilized peptide; protect from moisture and light. |
| Typical analytical method | HPLC and mass spectrometry | Used to confirm identity and estimate purity. |
| Common synonyms | AOD9604; hGH 176-191 | Naming varies by supplier and publication. |
| Disulfide bonds | One | Affects folded structure and stability. |
| Typical research purity | ≥95% | Value depends on supplier and analytical method. |
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.
A central uncertainty is whether observed metabolic changes translate into meaningful clinical benefits. Study designs vary in dose, duration, and participant characteristics, making comparisons difficult. Independent replication is limited, and the field lacks consensus on optimal endpoints or treatment duration. Ongoing or future studies may clarify mechanism and effect size, but current evidence does not establish a clear therapeutic role. Researchers often call for larger, longer, and better-controlled trials, while questions remain about which patient groups might respond.
AOD-9604 is a synthetic peptide whose sequence matches the C-terminal fragment of human growth hormone, specifically residues 176 through 191. This region differs from the full hormone in its receptor interactions. The peptide is not a growth hormone secretagogue and does not bind the growth hormone receptor in the same manner. Researchers have examined it for effects on lipid metabolism, but its exact pharmacological profile remains an active area of study.
Development of AOD-9604 began in the 1990s as scientists sought to isolate metabolic effects of growth hormone without its growth-promoting actions. Early laboratory work focused on fat cells and animal models. Several human trials followed, examining changes in body composition and fat mass. Results have been mixed, and the peptide has not progressed to widespread clinical approval. Interest continues in research settings, particularly regarding its mechanism and potential metabolic targets.
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.
In particular, VADAR’s secondary structure assignments appear to agree more closely with secondary structures identified by visual inspection (i.e. author assignments), by STRIDE (another secondary structure assignment algorithm) or via independent methods (i.e. NMR-based NOE methods).
== Gas separation discovery and development == At Innsbruck, Cremer researched the hydrogenation of acetylene and found difficulty separating two gases with similar adsorption heats using the common methods of the day. She was aware of the liquid absorption chromatography research going on at Innsbruck, so she thought of a parallel method to separate gases which used an inert carrier gas as the mobile phase. She developed mathematical relationships and equations and instrumentation for the first gas chromatograph. Separate components were detected by a thermal conductivity detector. She initially submitted a short academic paper in 1944 to Naturwissenschaften, which was accepted and she informed them that future experimental work would follow. The paper however was not published at the time, because the journal's printing press was destroyed during air bombardment. It was finally published thirty years later in 1976 at which point it was considered a historical document. In December 1944, the university's facilities were badly damaged in an air bombardment and after the war, Cremer, as a German citizen, was not allowed to use the limited facilities. Fritz Prior was one of her postwar students and a high school chemistry teacher. He chose her idea of the gas chromatograph for his dissertation. Until facilities at the University of Innsbruck were usable again, he used his high school's laboratory to continue Cremer's research with her.
McDivitt must have switched to the VOX setting somewhere around the time White was exiting the spacecraft, because at that point, for most of the EVA, neither he nor White responded either to the Hawaii CAPCOM, or to the Houston CAPCOM, Gus Grissom. Grissom tried to talk to Gemini 4 a total of 40 times in 13 minutes before he got a response. Tied to a tether, White floated out of the spacecraft, using a Hand-Held Maneuvering Unit (informally called a "zip gun") which expelled pressurized oxygen to provide thrust for controlling his travel. He went 4.6 meters (15 ft) out and began to experiment with maneuvering. He found it easy, especially the pitch and yaw, although he thought the roll would use too much gas. He maneuvered around the spacecraft while McDivitt took photographs. White enjoyed the experience, but exhausted the HHMU gas sooner than he would have liked. White was running up against two factors which constrained the time for his EVA: loss of signal from the Bermuda tracking station and crossing the solar terminator. The flight controllers were becoming increasingly frustrated with their inability to remind White of the time constraint, because they didn't want the first EVA to be performed in darkness or out of communication with Earth. Finally McDivitt decided to take his microphone off VOX:
Sources: en.wikipedia.org
=== Insects and fish === It is attractive to males of various species of orchid bees, which apparently gather the chemical to synthesize pheromones; it is commonly used as bait to attract and collect these bees for study. It also attracts female cucumber beetles. Eugenol and isoeugenol, which both are floral volatile scent compounds, are catalyzed by a single type of enzyme in the genus Gymnadenia and the gene encoding for this enzyme is the first functionally characterized gene in these species. Eugenol is an ingredient in some insecticides. Clove oil is common as an anesthetic for use on aquarium fish as well as on wild fish when sampled for research and management purposes. Where readily available, it presents a humane method to euthanize sick and diseased fish either by direct overdose or to induce sleep before an overdose of eugenol.
Raymond Ashley Fulton. For services to Music in Northern Ireland. Dr. Christine Paula Futter. Lately Chief Operating Officer, Norfolk and Suffolk Care Support Ltd. For services to Adult Social Care. Jacqueline Mary Gange. Volunteer, Cannock Chase Advice Centre. For services to the community in Cannock, Staffordshire. Nicholas George Anthony Gardner. For charitable services in Scotland. William Thomas Gavan. Mayor, Sandwell Council. For Political and Public Service, and to the LGBT+ Community. Deborah Gillian Greenslade Geany. Senior Case Manager, Personnel Recovery Unit Wales and West, Ministry of Defence. For services to Military Personnel. Syed Jason Andrew Ghaboos. Deputy Director, Civil Service Employee Experience, Cabinet Office. For Public Service. Professor Panagiotis Giannoudis. Professor of Trauma and Orthopaedics, University of Leeds and Founder, Day One Trauma Support. For services to Trauma and Orthopaedic Surgery. Dr. Dinendra Singh Gill. For services to Pre-Hospital and Trauma Care in Wales. Charity Gladstone. Lately Matron of Cardiology and Respiratory Services, Gloucestershire Hospitals NHS Foundation Trust. For services to Nursing. Jill Sylvia Gladwell. Poppy Appeal Collector. For voluntary services to the Royal British Legion in Suffolk. Judith Anne Godden. Head of Casework, Constituency Office of Tim Farron MP. For services to the community in Westmorland and Lonsdale, Cumbria. Dr. Claire Mairead Goodman. Professor of Health Care Research, Centre for Research in Public Health and Community Care, University of Hertfordshire. For services to Older People.
=== In the United States of America === Clinical pathologists work in close collaboration with clinical scientists (clinical biochemists, clinical microbiologists, etc.), medical technologists, hospital administrators, and referring physicians to ensure the accuracy and optimal utilization of laboratory testing. Clinical pathology is one of the two major divisions of pathology, the other being anatomical pathology. Often, pathologists practice both anatomical and clinical pathology, a combination sometimes known as general pathology. Similar specialties exist in veterinary pathology. Clinical pathology is itself divided into subspecialties, the main ones being clinical chemistry, clinical hematology/blood banking, hematopathology and clinical microbiology and emerging subspecialties such as molecular diagnostics and proteomics. Many areas of clinical pathology overlap with anatomic pathology. Both can serve as medical directors of CLIA certified laboratories. Under the CLIA law, only the US Department of Health and Human Services approved Board Certified Ph.D., DSc, or MD and DO can perform the duties of a Medical or Clinical Laboratory Director. This overlap includes immunoassays, flow cytometry, microbiology and cytogenetics and any assay done on tissue. Overlap between anatomic and clinical pathology is expanding to molecular diagnostics and proteomics as we move towards making the best use of new technologies for personalized medicine.
Sources: en.wikipedia.org
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.
The World Anti-Doping Agency classifies it as a prohibited peptide hormone. Athletes under anti-doping rules are not permitted to use it. Its presence can trigger a doping violation.
It is a fragment of growth hormone rather than a substance that signals the pituitary to release more hormone. Studies have not shown a consistent rise in IGF-1 or full growth hormone. Its metabolic effects, if any, appear separate from those of the complete hormone.
No, it is a synthetic peptide fragment corresponding to a small portion of hGH. It is not the full 191-amino-acid hormone and does not reproduce all of hGH's effects.