If you have been reading about CAS Registry Number 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.
Last reviewed on 2026-03-02. Where a claim depends on a specific study, the study is described rather than over-claimed.
Dihexa is a synthetic peptide that has been examined in laboratory and animal research. Its design is based on angiotensin IV, a naturally occurring peptide fragment produced in the body. The short name dihexa appears in scientific papers and online discussions, while the full chemical name describes a modified peptide chain. It is not a vitamin, mineral, or plant-derived compound. Suppliers typically present it as a research chemical rather than an approved medicine.
The full name often given is N-hexanoic-Tyr-Ile-(6)-aminohexanoic amide. This name indicates a chain containing tyrosine, isoleucine, and a six-carbon amino acid derivative. Databases list a CAS Registry Number and a molecular formula for the compound. The peptide is small compared with proteins, and its structure allows it to be studied in cell cultures and animal models. Exact identity depends on the supplier's synthesis and purification process. Minor impurities can remain after synthesis.
Most published work on dihexa consists of preclinical studies using cell cultures or rodents. Reports have described effects on synaptic connectivity and performance on cognitive tasks in some animal models. These findings are generally presented as preliminary and require independent replication. Study designs, doses, and outcome measures vary across experiments, which complicates direct comparison. No large controlled human trials have established efficacy or safety for any medical use. At present, the evidence base is limited.
Regulatory agencies have not approved dihexa as a prescription drug or supplement. In many countries it falls into a gray area when sold for laboratory research. Buyers may encounter products marketed for research use only, which are not intended for human consumption. Purity and identity can vary between suppliers and batches. Certificates of analysis and independent testing are often recommended for research materials. Documentation helps verify what a vial contains.
Discussion of dihexa in online communities sometimes outpaces the scientific record. Anecdotal reports are difficult to verify and may not distinguish effects from placebo or expectation. The absence of approved human data means long-term risks remain unknown. Researchers continue to investigate related compounds and pathways. Open questions include whether animal findings translate to humans and which biological targets matter most. No consensus exists on these points. Current reviews emphasize the need for rigorous clinical research.
| Property | Value | Notes |
|---|---|---|
| Common name | Dihexa | Shorthand used in research literature and supplier catalogs. |
| CAS Registry Number | 1401708-83-5 | Identifier assigned to the synthetic peptide. |
| Molecular formula | C27H44N4O5 | Reported formula; verify with a certificate of analysis. |
| Appearance | White to off-white powder | Typical form for lyophilized research peptides. |
| Typical storage | −20 °C or below, desiccated | Common condition for peptide stability. |
Dihexa is a synthetic compound studied in laboratory and animal models for effects on synaptic connectivity and cognitive performance. It is often described as a peptide analog because its structure incorporates amino acid residues linked to a hexanoic acid group. The molecule is not a naturally occurring human hormone or neurotransmitter. Its name appears in research literature and online discussions, but it has not been approved as a medicine by major regulatory agencies. Most information comes from preclinical experiments rather than controlled human trials.
The compound originated from work on angiotensin IV, a peptide fragment of the renin-angiotensin system. Researchers modified angiotensin IV-related structures to produce molecules with altered stability and activity. Dihexa emerged from that effort and was reported to promote dendritic spine growth in cultured neurons. Some studies link its effects to hepatocyte growth factor signaling and the c-Met receptor, while other work points to insulin-regulated aminopeptidase. The precise primary target remains a subject of investigation, and findings may depend on cell type, assay conditions, and species.
In laboratory settings, dihexa is typically handled as a research chemical rather than a pharmaceutical product. Suppliers may provide it as a lyophilized powder or in solution, and purity is often stated as a percentage determined by chromatographic analysis. Because independent verification is uncommon, researchers generally rely on certificates of analysis, which may include high-performance liquid chromatography and mass spectrometry data. The absence of pharmacopeial monographs means that identity, purity, and impurity profiles can vary between batches and suppliers.
Storage recommendations for peptides and peptide-like compounds usually emphasize low temperatures, desiccation, and protection from light. A common practice is to keep dry powder at -20 °C or below and to prepare solutions shortly before use. Repeated freeze-thaw cycles may degrade the material, so aliquoting is often advised. Solubility depends on the solvent; aqueous solubility may be limited, and organic solvents such as dimethyl sulfoxide are sometimes used for stock solutions. Stability data specific to dihexa are sparse, so general peptide handling guidelines are often applied instead.
Dihexa is a synthetic peptide derived from angiotensin IV, a naturally occurring fragment of the renin-angiotensin system. Researchers modified the angiotensin IV structure to improve metabolic stability and central nervous system activity. It is frequently described as a hepatocyte growth factor mimetic because it can activate the c-Met receptor pathway in experimental systems. Its development reflects interest in small peptides that influence synaptic plasticity and cognitive processes. Most information comes from preclinical studies rather than controlled human trials.
The compound has been examined in animal models for effects on learning, memory, and synaptic connectivity. Some reports describe increased dendritic spine density and improved performance on certain behavioral tasks after administration in rodents. These findings are often cited in discussions of nootropic research peptides, but replication across independent laboratories remains limited. The absence of published phase 1 or phase 2 clinical trial data makes it difficult to assess safety, effective routes, or long-term outcomes in humans. Consequently, claims about cognitive benefits in people remain speculative.
Lyophilized dihexa is typically stored as a dry powder at or below minus twenty degrees Celsius. Cooler temperatures slow degradation, and desiccant protection limits moisture uptake. Repeated temperature cycling can accelerate breakdown, so aliquoting before storage is common in laboratory practice. Solutions are generally less stable than dry powder and are often kept cold, protected from light, and used within a defined period. Specific stability data for dihexa are limited, and handling recommendations often follow general peptide guidelines rather than compound-specific studies.
Identity and purity are usually assessed with reverse-phase high-performance liquid chromatography and mass spectrometry. These methods can separate related impurities and confirm molecular mass, but they do not by themselves establish biological activity. Certificate of analysis documents may report purity as a percentage by area, yet the exact meaning can vary between laboratories. Independent testing can check for residual solvents, counterions, or microbial contamination when relevant. For research use, matching analytical records to a specific lot helps trace experimental variability.
There are several geophysical methods available that can approximate in situ soil water content. These methods include: time-domain reflectometry (TDR), neutron probe, frequency domain sensor, capacitance probe, amplitude domain reflectometry, electrical resistivity tomography, ground penetrating radar (GPR), and others that are sensitive to the physical properties of water . Geophysical sensors are often used to monitor soil moisture continuously in agricultural and scientific applications.
The branch of medical science that deals with the study of incidence and distribution and control of a disease in a population. (NLM) The study of the patterns, causes, and control of disease in groups of people. (NCI) Equivalence trial
=== T7 phages === The issue of using Ff phages for phage display is that they require the protein of interest to be translocated across the bacterial inner membrane before they are assembled into the phage. Some proteins cannot undergo this process and therefore cannot be displayed on the surface of Ff phages. In these cases, T7 phage display is used instead. In T7 phage display, the protein to be displayed is attached to the C-terminus of the gene 10 capsid protein of T7. The disadvantage of using T7 is that the size of the protein that can be expressed on the surface is limited to shorter peptides because large changes to the T7 genome cannot be accommodated like it is in M13 where the phage just makes its coat longer to fit the larger genome within it. However, it can be useful for the production of a large protein library for scFV selection where the scFV is expressed on an M13 phage and the antigens are expressed on the surface of the T7 phage.
Sources: en.wikipedia.org
== Development == The development of the embryo is completely reliant on the vitelline circulation, the bidirectional flow of blood between the yolk sac and the embryo. The yolk sac is the first extraembryonic structure to appear. This circulation is critical in allowing the exchange of nutrients, prior to the full development of the placenta. By day 17 vessels begin to form in the yolk sac, arising from the splanchnic mesoderm of the yolk sac wall. The capillaries are formed during vasculogenesis, and they lengthen and interconnect to form an extensive primitive vascular network. Blood is supplied from the primitive aorta, and drained by vitelline veins from the yolk sac to the embryo. By the end of the third week the yolk sac, connecting stalk, and chorionic villi are entirely vascularised. In the middle of the fourth week the heart begins to beat and the circulation of blood begins. The primitive outflow tract is of three pairs of aortic arches. The inflow tract is formed of six paired veins, the vitelline veins, umbilical veins, and the cardinal veins.
== Description == Lotus plants are adapted to grow in the flood plains of slow-moving rivers and delta areas. Stands of lotus drop hundreds of thousands of seeds every year to the bottom of the pond. Some sprout immediately, though most are eaten by wildlife. The remaining seeds can remain dormant for an extensive period of time as the pond silt fills in and dries out. During flood conditions, sediments containing these seeds are broken open, and the dormant seeds rehydrate and begin a new lotus colony. Lotus plants are cultivated in nutrient-rich, loamy, and often flooded soils, requiring warm temperatures and specific planting depths, with propagation via rhizomes, seeds, or tissue culture. It is harvested by hand or machine for stolons, flowers, seeds, and rhizomes over several months depending on climate and variety. It is the national flower of India and unofficially of Vietnam. It has large leaves and flowers that can regulate their temperature, produces long-living seeds, and contains bioactive alkaloids. Under favourable circumstances, the seeds of this aquatic perennial may remain viable for many years, with the oldest recorded lotus germination being from seeds 1,300 years old recovered from a dry lakebed in northeastern China. Therefore, the Chinese regard the plant as a symbol of longevity.
The possibility that dinosaurs were the ancestors of birds was first suggested in 1868 by Thomas Henry Huxley. After the work of Gerhard Heilmann in the early 20th century, the theory of birds as dinosaur descendants was abandoned in favor of the idea of them being descendants of generalized thecodonts, with the key piece of evidence being the supposed lack of clavicles in dinosaurs. However, as later discoveries showed, clavicles (or a single fused wishbone, which derived from separate clavicles) were not actually absent; they had been found as early as 1924 in Oviraptor, but misidentified as an interclavicle. In the 1970s, John Ostrom revived the dinosaur–bird theory, which gained momentum in the coming decades with the advent of cladistic analysis, and a great increase in the discovery of small theropods and early birds. Of particular note have been the fossils of the Jehol Biota, where a variety of theropods and early birds have been found, often with feathers of some type. Birds share over a hundred distinct anatomical features with other theropod dinosaurs. They are most closely allied with maniraptoran coelurosaurs. A minority of scientists, most notably Alan Feduccia and Larry Martin, have proposed other evolutionary paths, including revised versions of Heilmann's basal archosaur proposal, or that maniraptoran theropods are the ancestors of birds but themselves are not dinosaurs, only convergent with dinosaurs.
Sources: en.wikipedia.org
== Education and career == Hong grew up in China and completed her B.A. degree in chemistry from Mount Holyoke College (summa cum laude) in 1992 and a Ph.D. degree from the University of California, Berkeley in 1996. There she worked in the laboratory of Alexander Pines to investigate phospholipid structure and dynamics using variable-angle-spinning NMR. After a one-year postdoctoral stint in the laboratory of Robert G. Griffin at the Massachusetts Institute of Technology, she went to University of Massachusetts Amherst and developed biosynthetic isotopic labeling approaches to advance protein structure determination by ssNMR. She started an assistant professorship at Iowa State University in 1999, became an associate professor in 2002 and full professor in 2004, and held the first John D. Corbett Professorship from 2007 to 2010. In 2014, she returned to the Massachusetts Institute of Technology as a professor of chemistry.
Merck & Co. traces its origins to its former German parent company the Merck Group, which was established by the Merck family in 1668 when Friedrich Jacob Merck purchased a pharmacy in Darmstadt. In 1827, Merck Group evolved from a pharmacy to a drug manufacturer company with the commercial manufacture of morphine. Merck perfected the chemical process of deriving morphine from opium and later introduced cocaine, used to treat sinus problems and to add to beverages to boost energy levels. In 1887 a German-born, long-time Merck employee, Theodore Weicker, went to the United States to represent Merck Group. In 1891, with $200,000 received from E. Merck, Weicker started Merck & Co., with headquarters in lower Manhattan. That year George Merck, the 23-year-old son of the then head of E. Merck (and grandson of the founder) joined Weicker in New York. Merck & Co. operated from 1891 to 1917 as the US subsidiary of the Merck Group.
As the head group forms such compact bicycle structure, the head group area is quite small relative to the big tail region consisting of 4 acyl chains. Based on this special structure, the fluorescent mitochondrial indicator, nonyl acridine orange (NAO) was introduced in 1982, and was later found to target mitochondria by binding to CL. NAO has a very large head and small tail structure which can compensate with cardiolipin's small head and large tail structure, and arrange in a highly ordered way. Several studies were published utilizing NAO both as a quantitative mitochondrial indicator and an indicator of CL content in mitochondria. However, NAO is influenced by membrane potential and/or the spatial arrangement of CL, so it's not proper to use NAO for CL or mitochondria quantitative studies of intact respiring mitochondria. But NAO still represents a simple method of assessing CL content.
Sources: en.wikipedia.org
Dihexa is a synthetic peptide modeled on angiotensin IV. It is used in laboratory and animal research, not as an approved medicine. Human effects remain poorly characterized.
It is produced by chemical synthesis, not extracted from plants or animals. Its design is based on a naturally occurring peptide fragment. Suppliers sell it as a research chemical.
No, dihexa is a modified analog of angiotensin IV. The two share a structural relationship but differ in chemical details. Research on one does not automatically apply to the other.
Published human trials are lacking. Most evidence comes from laboratory and animal studies. Therefore, human benefits and risks are not established.