metabolic research raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-10-21 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Peptide fragment | Corresponds to hGH residues 176-191 |
| Common synonyms | AOD9604, hGH 176-191 | Also written as AOD-9604 |
| Typical form | Lyophilized powder | Often supplied in sealed vials |
| Solubility | Water-soluble | Dissolves in aqueous buffers |
| Regulatory status | Not approved as drug | Banned in sport; varies by country |
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.
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.
== Mode of action == The exact activation mechanism of Ppk1/Ppk26 ion channels in the presence of Do6a is unknown; however, it likely compares to the mode of action of endogenous peptide Vulnusin due to their similarity in structure. Vulnusin binds to Ppk/Bba channels upon mechanical injury, yet administration of this peptide independently still results in channel activation and nociceptive rolling in Drosophila larvae. This could mean that a wound in larvae tissue allows Vulnusin, normally located above the epidermal layer, to reach its receptors below epidermal cells. Do6a, delivered to Ppk/Bba receptors through a mechanical puncture of the tissue from the velvet ant sting, could elicit its response through a similar mechanism. Since Ppk1/Ppk26 ion channels are homologous to Acid-sensing ion channels (ASICs) in vertebrates, they are likely to be permeable to cations, however, the exact ion type that passes through these channels upon activation has not been determined.
=== Protandim voluntary recall === In December 2012, LifeVantage issued a voluntary recall of select lots (ten lots in total comprising 247,896 bottles) of Protandim due to potential health risks arising from the possible inclusion of small metal fragments in the final product. In February 2013, the company announced that it was extending the recall to include additional lots of the product, estimating the total cost of the recall at $5.9 million.
=== Persons with disabilities === During 2025, the Karnataka Labour Department worked on a proposed legislative framework for reservations for persons with disabilities in education and private-sector employment. The draft framework proposed up to 10 percent reservation in educational institutions and 5 percent in private-sector employment, subject to legislative and policy processes.
Sources: en.wikipedia.org
=== Brand names === Cyclofenil has been marketed under a variety of brand names including Ciclifen, Fertodur, Gyneuro, Klofenil, Menoferil, Menopax, Neoclym, Oginex, Ondonid, Ondogyne, Rehibin, Sexadieno, Sexovar, and Sexovid.
UO2 + 4 HF → UF4 + 2 H2O (500 °C, endothermic) UF4 + F2 → UF6 (350 °C, endothermic) The resulting UF6, a white solid, is highly reactive (by fluorination), easily sublimes (emitting a vapor that behaves as a nearly ideal gas), and is the most volatile compound of uranium known to exist. Uranium hexafluorides (IV) and (V) can be used to make several hexafluorouranates, as they are anions (UF6- and UF62-). They bond with alkali metals, certain transition metals, and other non-metal compounds. One method of preparing uranium tetrachloride (UCl4) is to directly combine chlorine with either uranium metal or uranium hydride. The reduction of UCl4 by hydrogen produces uranium trichloride (UCl3) while the higher chlorides of uranium are prepared by reaction with additional chlorine. All uranium chlorides react with water and air. Bromides and iodides of uranium are formed by direct reaction of, respectively, bromine and iodine with uranium or by adding UH3 to those element's acids. Known examples include: UBr3, UBr4, UI3, and UI4. UI5 has never been prepared. Uranium oxyhalides are water-soluble and include UO2F2, UOCl2, UO2Cl2, and UO2Br2. Stability of the oxyhalides decrease as the atomic weight of the component halide increases.
=== Space exploration === Synthetic biology raised NASA's interest as it could help to produce resources for astronauts from a restricted portfolio of compounds sent from Earth. On Mars, in particular, synthetic biology could lead to production processes based on local resources, making it a powerful tool in the development of occupied outposts with less dependence on Earth. Work has gone into developing plant strains that are able to cope with the harsh Martian environment, using similar techniques to those employed to increase resilience to certain environmental factors in agricultural crops.
over a longer period of evolutionary time. Each amino acid is more or less likely to mutate into various other amino acids. For instance, a hydrophilic residue such as arginine is more likely to be replaced by another hydrophilic residue such as glutamine, than it is to be mutated into a hydrophobic residue such as leucine. (Here, a residue refers to an amino acid stripped of a hydrogen and/or a hydroxyl group and inserted in the polymeric chain of a protein.) This is primarily due to redundancy in the genetic code, which translates similar codons into similar amino acids. Furthermore, mutating an amino acid to a residue with significantly different properties could affect the folding and/or activity of the protein. This type of disruptive substitution is likely to be removed from populations by the action of purifying selection because the substitution has a higher likelihood of rendering a protein nonfunctional. If we have two amino acid sequences in front of us, we should be able to say something about how likely they are to be derived from a common ancestor, or homologous. If we can line up the two sequences using a sequence alignment algorithm such that the mutations required to transform a hypothetical ancestor sequence into both of the current sequences would be evolutionarily plausible, then we'd like to assign a high score to the comparison of the sequences. To this end, we will construct a 20x20 matrix where the
Sources: en.wikipedia.org
AOD-9604 is a synthetic peptide fragment of human growth hormone, corresponding to amino acids 176-191. It is studied for potential effects on fat metabolism, but it is not approved as a drug in most countries. Its exact mechanism remains under investigation.
No, it is a small fragment of the full growth hormone protein. It does not appear to stimulate growth or increase growth hormone levels in the same way. Its actions are thought to be more limited to metabolic pathways.
Regulatory status varies. It is not approved for medical use in the United States or many other countries. It is banned in sport by WADA, and its sale as a supplement or research chemical may be subject to legal restrictions.
It is a synthetic peptide based on a C-terminal fragment of human growth hormone. It is commonly referred to as hGH fragment 176-191 and is studied for metabolic effects rather than growth effects.