This is a working overview of synthetic peptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-11-18 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | Derived from a fragment of human growth hormone |
| Sequence basis | hGH residues 176-191 | Commonly described as a 16-amino-acid fragment |
| Appearance | White to off-white powder | Typical for lyophilized research peptides |
| Solubility | Soluble in water or aqueous buffer | Exact solubility depends on pH and purity |
| Common synonyms | AOD9604; hGH 176-191 | Spelling and punctuation vary across sources |
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.
Regulatory status varies by country. In the United States, AOD-9604 is not approved as a prescription drug. It is sometimes sold as a research chemical or dietary supplement, though such marketing may fall outside legal frameworks. The World Anti-Doping Agency prohibits its use in sport. Researchers must obtain it through legitimate suppliers and follow institutional rules. Its legal classification continues to evolve as authorities increasingly assess peptide products more broadly.
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.
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.
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.
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.
Commercial AOD-9604 may vary in purity, counterion content, and residual moisture. Certificates of analysis often report HPLC purity, mass confirmation, and appearance, but testing methods differ between suppliers. Independent verification is sometimes used because labeled content may not match actual peptide amount. Stability under different pH and temperature conditions is not fully standardized across studies. Researchers generally treat lyophilized material as the reference form for weighing and reconstitution. Moisture content can affect accurate mass measurement.
AOD-9604 is typically supplied as a lyophilized white to off-white powder. In this form, it is relatively stable when kept cool, dry, and protected from light. Common storage recommendations place it at −20 °C or below for long-term retention. Reconstituted solutions are less stable and are often kept at 2–8 °C for short periods. Freeze-thaw cycles should be minimized because they can promote aggregation or loss of peptide content. Vials are usually sealed under inert gas to reduce oxidation.
Identity and purity are commonly checked with reversed-phase high-performance liquid chromatography and mass spectrometry. RP-HPLC separates the peptide from related impurities and can estimate purity by peak area. Mass spectrometry confirms molecular mass and helps detect sequence variants or truncations. Some laboratories use amino acid analysis or peptide mapping for additional characterization. No single method proves biological activity; these techniques establish chemical identity and purity only. They also require suitable reference standards for confident comparison.
== Function == NAXE binds to APOA1, APOA2, and high-density lipoprotein (HDL). In addition, APOA1BP appears to play a role in sperm capacitation. It has been demonstrated that APOA1BP is involved in angiogenesis regulation, by accelerating cholesterol efflux from endothelial cells to HDL. It is known that zebrafish NAXE ortholog Aibp is involved in angiogenesis regulation. The protein was also shown to be involved in atherosclerosis protection.
== Bibliography == Escoffier, Auguste (1903). Le Guide culinaire. Aide mémoire de cuisine pratique. Paris, France: Flammarion. Escoffier, Auguste (1907). A Guide to Modern Cookery. Heinemann. OL 24167463M. Escoffier, A (1941). The Escoffier Cook Book. New York: Crown Publishers. Fannie Merritt Farmer (1896). The Boston Cooking-School Cook Book. Boston, Massachusetts: Little, Brown and Company. Beck, Simone; Louisette Bertholle; Julia Child (1961). Mastering the Art of French Cooking. New York: Alfred A. Knopf.
Instead of in the liquid phase, the dehydrochlorination may also be carried out in the gas phase on a zinc chloride impregnated catalyst in a fluidized bed reactor at 350-500 °C. The seemingly simple reaction yields only 70 to 80% of impure end product due to a variety of side reactions. For example, in the chlorination of ethylene carbonate in substance or solution, 2-chloroacetaldehyde, polychlorinated ethylene carbonate and chlorinated ring-opening products are formed besides others. The separation of the by-products from the final product by distillation by thin-film evaporator, fractional recrystallization or zone melting is very expensive. The content of by-products can be reduced by stirring with sodium borohydride or urea at elevated temperature. However, the purification is complicated by the pronounced thermolability of vinylene carbonate, as it decomposes at temperatures above 80 °C within minutes. Highly pure vinylene carbonate can be obtained in yields of more than 70% by optimizing the chlorination conditions to suppress the formation of by-products and a combination of several gentle purification processes. The tendency of the liquid vinylene carbonate to polymerize is suppressed by addition of inhibitors such as butylhydroxytoluene (BHT).
Sources: en.wikipedia.org
Vital Brazil was attracted by medical research in the growing fields of bacteriology, virology and immunology at the end of the 19th century, which were being fueled by the great discoveries in Europe, by Louis Pasteur, Robert Koch, Paul Ehrlich and many others. In 1896, when he was still working in Botucatu, Vital Brazil became specially interested in snake incidents and began his studies on snake poisoning, also keeping a scientific collection of snakes stored in alcohol. He therefore returned to São Paulo in 1897 and accepted a position in the Instituto Bacteriológico de São Paulo (Bacteriological Institute of São Paulo), under direction of the great Brazilian pathologist and epidemiologist Adolfo Lutz. There, he worked on the preparation of sera against several diseases, particularly bubonic plague, of which he fell gravely ill, fortunately surviving it. Due to his outstanding work, the government of São Paulo founded a new Serum Therapy Institute in 1901 and gave its directorship to Vital Brazil. He also founded the Institute of Hygiene, Serum Therapy and Veterinary Medicine in the city of Niterói, in 1919, which is called today Vital Brazil Institute (Instituto Vital Brazil). Vital Brazil carried out scientific travels to Europe in 1904 and 1914 and to 1925 to the United States. He continued working at the Butantan Institute for several decades until his retirement in 1919. He died on May 8, 1950, celebrated as one of the most important Brazilian scientists ever.
Conservative MP Bob Stewart is found guilty of a racially aggravated public order offence after telling an activist to "go back to Bahrain". BBC News reports that Matthew White, the sixth suspect in the murder of Stephen Lawrence, allegedly confessed to involvement in the killing when he tried to stab a security guard while shoplifting from a supermarket in 2015. Sunak warns that protests planned for Armistice Day on 11 November would be "provocative and disrespectful". 4 November A further allegation of sexual assault is made against Russell Brand, dating from 2010. Home Secretary Suella Braverman announces a plan to deter "those who cause nuisance ... by pitching tents in public spaces" by making it harder for homeless people to access tents, describing it as a "lifestyle choice". Around 100 people are injured after a cruise ship, the Spirit of Discovery, owned by Saga Cruises, is caught in a storm in the Bay of Biscay. 6 November Following a trial at Birmingham Crown Court, Mohammed Abbkr is convicted of attempted murder after he set two elderly worshippers alight after they left mosques in London and Birmingham. The Metropolitan Police urges the organisers of pro-Palestinian marches to delay events planned for Armistice Day. 7 November Charles III attends the 2023 State Opening of Parliament, his first as King. Anastrozole, a drug used for a number of years to treat breast cancer, is licensed for use in England as a preventative option. Prince William announces the five winners of the annual Earthshot Prize.
=== Toxicity due to size of nanoparticles === Toxicity in certain systems can also be dependent on the size of the nanoparticle. AuNSs size 1.4 nm were found to be toxic in human skin cancer cells (SK-Mel-28), human cervical cancer cells (HeLa), mouse fibroblast cells (L929), and mouse macrophages (J774A.1), while 0.8, 1.2, and 1.8 nm sized AuNSs were less toxic by a six-fold amount and 15 nm AuNSs were nontoxic. There is some evidence for AuNP buildup after injection in in vivo studies, but this is very size dependent. 1.8 nm AuNPs were found to be almost totally trapped in the lungs of rats. Different sized AuNPs were found to build-up in the blood, brain, stomach, pancreas, kidneys, liver, and spleen. Biosafety and biokinetics investigations on biodegradable ultrasmall-in-nano architectures have demonstrated that gold nanoparticles are able to avoid metal accumulation in organisms through escaping by the renal pathway.
=== Preimplantation genetic diagnosis === Embryos produced using in vitro fertilization may be genetically tested for HD using preimplantation genetic diagnosis. This technique, where one or two cells are extracted from a typically 4- to 8-cell embryo and then tested for the genetic abnormality, can then be used to ensure embryos affected with HD genes are not implanted, so any offspring will not inherit the disease. Some forms of preimplantation genetic diagnosis—non-disclosure or exclusion testing—allow at-risk people to have HD-free offspring without revealing their own parental genotype, giving no information about whether they themselves are destined to develop HD. In exclusion testing, the embryo's DNA is compared with that of the parents and grandparents to avoid inheritance of the chromosomal region containing the HD gene from the affected grandparent. In nondisclosure testing, only disease-free embryos are replaced in the uterus while the parental genotype and hence parental risk for HD are never disclosed.
Sources: en.wikipedia.org
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.
It is commonly described as a 16-amino-acid peptide based on residues 176-191 of human growth hormone. Some sources vary in notation, so checking the stated sequence is useful.
It is not typically described as a standalone natural hormone. The sequence is derived from the C-terminal region of human growth hormone, but the synthetic peptide is a laboratory-made construct.
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.