If you have been reading about hGH fragment 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 2025-12-09. Numbers and descriptions here follow the published literature rather than marketing material.
In the scientific literature, AOD-9604 appears in reviews of growth hormone fragments and in discussions of peptide-based metabolic research. Some sources distinguish it from growth hormone itself, while others group it with compounds marketed for weight management. The evidence base is small compared with approved obesity medications. Questions about long-term efficacy and clinical relevance remain open, and independent replication of key findings is limited. Most published reports are early-stage and exploratory.
AOD-9604 is a synthetic peptide modeled on the C-terminal region of human growth hormone. It is often described as hGH fragment 176-191. Research interest arose because it was designed to isolate possible effects on fat metabolism from other actions of growth hormone. It is not a full growth hormone molecule. Its development history includes early laboratory and animal studies followed by human trials. The peptide has been examined in laboratory, animal, and limited human studies.
The compound has been studied as a potential treatment for obesity and related metabolic conditions. Published trials have examined changes in body weight, fat mass, and safety markers over limited durations. Results have been mixed or modest, and no large-scale outcome trials are established. Regulatory agencies in several countries have not approved it as a therapeutic drug. Some commercial products have been marketed outside regulated pharmaceutical channels, which raises questions about quality and claims.
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 |
|---|---|---|
| Common synonym | hGH fragment 176-191 | Refers to the C-terminal segment |
| Appearance | White to off-white powder | Typically supplied lyophilized |
| Solubility | Soluble in water and aqueous buffers | Confirm with technical data |
| Typical storage temperature | -20 °C for dry powder | Protect from moisture and light |
| Common analytical method | RP-HPLC with UV detection | Often paired with mass spectrometry |
Regulatory status: AOD-9604 is not approved as a therapeutic drug in the United States, European Union, or other major markets. It is listed by the World Anti-Doping Agency as a prohibited substance in sport, specifically under growth hormone fragments. Many jurisdictions restrict its sale for human consumption. Products marketed online may not meet pharmaceutical quality standards. The legal status varies by country and often depends on whether the material is presented as a research chemical, supplement, or drug.
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.
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 is modeled on the C-terminal region of human growth hormone. Published descriptions commonly place it as a modified fragment corresponding to hGH amino acids 176–191, with a tyrosine residue added or retained at the N-terminus to support detection and handling. It is not intact growth hormone and lacks the full receptor-binding architecture of the parent protein. The molecule was developed as a research candidate for metabolic studies rather than as a replacement for growth hormone therapy. Its identity is defined by its amino acid sequence rather than by any single commercial preparation.
AOD-9604 drew attention in the 1990s and 2000s as a potential anti-obesity agent. Early work explored both injectable and oral routes, which is unusual for a peptide of this size. Animal studies reported changes in fat metabolism without the growth-promoting or insulin-like effects associated with full-length growth hormone. Subsequent human trials produced mixed or modest results, and the compound did not obtain regulatory approval for weight management in major markets. It remains known mainly through research literature, sports anti-doping listings, and non-approved supplement advertising.
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.
=== Acute inflammation === When there is a stimulus, the CRP level can increase 10,000-fold from less than 50 μg/L to more than 500 mg/L. Its concentration can increase to 5 mg/L by 6 hours and peak at 48 hours. The plasma half-life of CRP is 19 hours, and is constant in all medical conditions. Therefore, the only factor that affects the blood CRP concentration is its production rate, which increases with inflammation, infection, trauma, necrosis, malignancy, and allergic reactions. Other inflammatory mediators that can increase CRP are TGF beta 1, and tumor necrosis factor alpha. In acute inflammation, CRP can increase as much as 50 to 100 mg/L within 4 to 6 hours in mild to moderate inflammation or an insult such as skin infection, cystitis, or bronchitis. It can double every 8 hours and reaches its peak at 36 to 50 hours following injury or inflammation. CRP between 100 and 500 mg/L is considered highly predictive of inflammation due to bacterial infection. Once inflammation subsides, CRP level falls quickly because of its relatively short half-life.
This is expected to delay the planned commissioning of the Hazer CDP, with commissioning now expected to occur after our current target date of 1Q 2022." The Hazer Group has collaboration agreements with Engie for a facility in France in May 2023, A Memorandum of Understanding with Chubu Electric & Chiyoda in Japan April 2023 and an agreement with Suncor Energy and FortisBC to develop 2,500 tonnes per Annum Burrard-Hazer Hydrogen Production Plant in Canada April 2022 The American company C-Zero's technology converts natural gas into hydrogen and solid carbon. The hydrogen provides clean, low-cost energy on demand, while the carbon can be permanently sequestered. C-Zero announced in June 2022 that it closed a $34 million financing round led by SK Gas, a subsidiary of South Korea's second-largest conglomerate, the SK Group. SK Gas was joined by two other new investors, Engie New Ventures and Trafigura, one of the world's largest physical commodities trading companies, in addition to participation from existing investors including Breakthrough Energy Ventures, Eni Next, Mitsubishi Heavy Industries, and AP Ventures. Funding was for C-Zero's first pilot plant, which was expected to be online in Q1 2023. The plant may be capable of producing up to 400 kg of hydrogen per day from natural gas with no CO2 emissions. One of the world's largest chemical companies, BASF, has been researching hydrogen pyrolysis for more than 10 years.
To bypass these effects, it is standard clinical practice to coadminister (with levodopa) a peripheral DOPA decarboxylase inhibitor (DDCI) such as carbidopa (medicines containing carbidopa, either alone or in combination with levodopa, are branded as Lodosyn (Aton Pharma) Sinemet (Merck Sharp & Dohme Limited), Pharmacopa (Jazz Pharmaceuticals), Atamet (UCB), Syndopa and Stalevo (Orion Corporation) or with a benserazide (combination medicines are branded Madopar or Prolopa), to prevent the peripheral synthesis of dopamine from levodopa). However, when consumed as a botanical extract, for example from M pruriens supplements, a peripheral DOPA decarboxylase inhibitor is not present. Inbrija (previously known as CVT-301) is an inhaled powder formulation of levodopa indicated for the intermittent treatment of "off episodes" in patients with Parkinson's disease currently taking carbidopa/levodopa. It was approved by the US Food and Drug Administration (FDA) on 21 December 2018, and is marketed by Acorda Therapeutics. Coadministration of pyridoxine without a DDCI accelerates the peripheral decarboxylation of levodopa to such an extent that it negates the effects of levodopa administration, a phenomenon that historically caused great confusion. In addition, levodopa, co-administered with a peripheral DDCI, is efficacious for the short-term treatment of restless leg syndrome. The two types of response seen with administration of levodopa are:
== Further reading == Griesemer RL (25 July 2008). Index of Central Obesity as a Parameter to Evaluate Metabolic Syndrome for White, Black, and Hispanic Adults in the United States (Master's thesis). Public Health Theses, Georgia State University. doi:10.57709/1062268. Archived from the original on 22 July 2012. Retrieved 4 June 2011. Lee K, Song YM, Sung J (April 2008). "Which obesity indicators are better predictors of metabolic risk?: healthy twin study". Obesity. 16 (4): 834–40. doi:10.1038/oby.2007.109. PMID 18239595. S2CID 1633972. Shao J, Yu L, Shen X, Li D, Wang K (November 2010). "Waist-to-height ratio, an optimal predictor for obesity and metabolic syndrome in Chinese adults". The Journal of Nutrition, Health & Aging. 14 (9): 782–5. doi:10.1007/s12603-010-0106-x. PMID 21085910. S2CID 11187741. Pant S (31 October 2025). "Normal BMI With Abdominal Obesity Associated With Cardiometabolic Risks". JAMA (Medical News in Brief). 334 (16): 1875. doi:10.1001/jama.2025.17532. PMID 41171291.
Sources: en.wikipedia.org
==== Neurosteroid activity ==== DHT, via its metabolite 3α-androstanediol (produced by 3α-hydroxysteroid dehydrogenase (3α-HSD)), is a neurosteroid that acts via positive allosteric modulation of the GABAA receptor. Testosterone, via conversion into DHT, also produces 3α-androstanediol as a metabolite and hence has similar activity. Some AAS that are or can be 5α-reduced, including testosterone, DHT, stanozolol, and methyltestosterone, among many others, can or may modulate the GABAA receptor, and this may contribute as an alternative or additional mechanism to their central nervous system effects in terms of mood, anxiety, aggression, and sex drive.
== Function == Microproteins function as post-translational regulators. Microproteins disrupt the formation of heterodimeric, homodimeric, or multimeric complexes. Furthermore, microproteins can interact with any protein that requires functional dimers to function normally. The primary targets are transcription factors that bind to DNA as dimers. Microproteins regulate these complexes by creating homotypic dimers with the targets and inhibit protein complex function. The two types of miP inhibitions are: homotypic miP inhibition and heterotypic miP inhibition. In homotypic miP inhibition, microproteins interact with proteins with similar protein-protein interaction (PPI) domain. In heterotypic miP inhibition, microproteins interact with proteins with different but compatible PPI domain. In both types of inhibition, microproteins interfere and prevent the PPI domains from interacting with their normal proteins. Microproteins plays roles in biological process such as immunity and inflammation, cancer and cell cycle regulation, cellular transport, muscle and heart functions, gene expression and genome maintenance, proteostasis, and metabolic homeostasis.
As the classification is most often used today, the oldest American think tank is the Carnegie Endowment for International Peace, founded in 1910. The Institute for Government Research, which later merged with two organizations to form the Brookings Institution, was formed in 1916. Other early twentieth century organizations now classified as think tanks include the Hoover Institution (1919), The Twentieth Century Fund (1919, and now known as the Century Foundation), the National Bureau of Economic Research (1920), the Council on Foreign Relations (1921), and the Social Science Research Council (1923). The Great Depression and its aftermath spawned several economic policy organizations, such as the National Planning Association (1934), the Tax Foundation (1937), and the Committee for Economic Development (1943). In collaboration with the Douglas Aircraft Company, the Air Force set up the RAND Corporation in 1946 to develop weapons technology and strategic defense analysis. The Hudson Institute is a conservative American think tank founded in 1961 by futurist, military strategist, and systems theorist Herman Kahn and his colleagues at the RAND Corporation. Recent members include Mike Pompeo, the former secretary of state under Donald Trump who joined in 2021. More recently, progressive and liberal think tanks have been established, most notably the Center for American Progress and the Center for Research on Educational Access and Leadership (CREAL). The organization has close ties to former United States President Barack Obama and other prominent Democrats.
Sources: en.wikipedia.org
It is a synthetic peptide fragment derived from the C-terminal region of human growth hormone, commonly referred to as hGH fragment 176-191. It has been investigated for effects on fat metabolism, but it is not an approved medication in most jurisdictions.
No. It is a shortened peptide fragment, not the full hormone. It does not contain the entire hGH sequence and is studied for different proposed effects.
Regulatory approvals for weight loss are not established in major jurisdictions. Some human trials reported modest changes, but the evidence is limited, and it remains a research compound.
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.