A practical reference on pentapeptide: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2026-02-07. Anything still debated is marked as such rather than presented as settled.
The molecule contains five residues, including alpha-aminoisobutyric acid, D-2-naphthylalanine, and D-phenylalanine, and it ends in a lysine amide. Non-natural and D-configured residues make the chain less susceptible to common peptidases, which helps explain its resistance to rapid breakdown. Its molecular formula is C38H49N9O5, corresponding to a free-base mass near 711.9 daltons. The C-terminal amide removes a negative charge and is a recurring feature in receptor-active peptides of this family. These structural choices are usually discussed as the basis for its selectivity profile.
Published animal and early human work describes growth hormone release that is separated from comparable rises in adrenocorticotropic hormone and cortisol. Prolactin changes are reported as small in the same studies. Selectivity is attributed to binding at the ghrelin receptor and to the downstream signaling that follows, rather than to differences in how quickly the peptide is cleared. Authors commonly label the compound selective rather than potent, because the same mass produces a smaller growth hormone response than some older secretagogues tested in parallel. Whether that profile holds across species and routes of administration remains an open question.
Human data remain limited and come mainly from small, short-term studies conducted decades ago. The peptide has not received approval as a medicine from major regulators, so current availability is largely as a research chemical. Reported effects on growth hormone pulsatility, appetite, and body composition should be read as preliminary, since few independent groups have replicated the original findings. Analytical characterization of research-grade material varies between suppliers, which complicates comparison across studies. Regulatory status also differs by country, and some jurisdictions classify it as a prescription-only or otherwise restricted item.
In animal and early human studies, ipamorelin produces pulsatile growth hormone release and a secondary rise in insulin-like growth factor 1. The magnitude and duration of that rise depend on route, sampling schedule, and the baseline endocrine state of the subject. Whether repeated exposure alters the response over time is not firmly settled, since some reports describe stable pulsatility while others note attenuation. Most published data come from small samples, which limits the strength of any general claim about long-term behavior.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class of compounds. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, a structure that differs from natural ghrelin in length and in the presence of non-natural amino acid residues. Early laboratory work described it as a comparatively selective agent that stimulates growth hormone release with limited effect on other pituitary hormones. The compound is supplied as a lyophilized solid for research use and has no identified natural source in the body.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Value for the free base |
| Molar mass | 711.9 g/mol | Calculated from the formula |
| Appearance | White to off-white powder | Typical lyophilized form |
| Mechanism class | Ghrelin receptor agonist | Also described as a secretagogue |
| Half-life | About 2 hours | Reported for human circulation |
At the molecular level, ipamorelin acts as an agonist at the growth hormone secretagogue receptor, also called the ghrelin receptor or GHS-R1a. Binding to this receptor on pituitary somatotroph cells triggers a signaling cascade that leads to growth hormone release. The effect is mediated through phospholipase C and calcium mobilization rather than through the cyclic AMP pathway used by growth hormone releasing hormone. The two pathways are complementary, and combined stimulation produces a larger response than either alone.
Compared with other secretagogues such as GHRP-2, GHRP-6, and hexarelin, ipamorelin is described as more selective. Published animal work reports little or no increase in adrenocorticotropic hormone, cortisol, or prolactin at doses that release growth hormone. This selectivity is the property most often cited in the research literature. Whether the same profile holds across species and dosing schedules remains an open question, since human data are limited and come largely from small studies.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue family. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, and its molecular mass is approximately 711.9 daltons. The compound was described in the late 1990s by researchers seeking molecules that release growth hormone with fewer side effects than earlier secretagogues. It is a laboratory and research compound, not an approved medicine in most jurisdictions.
冻干状态下的肽通常比溶液状态更稳定，常规做法是维持 -20 °C 或更低温度、保持干燥并避开强光。复溶后的降解主要来自水解、氧化与脱酰胺，速率受 pH、缓冲液种类、离子强度与温度共同影响，碱性条件一般会加快这些反应。反复冻融会造成聚集与容器吸附损失，分装保存能降低该风险。容器材质与金属离子也可能参与氧化过程，需与操作条件一并考虑。
对 ipamorelin 的常规表征以反相高效液相色谱测定纯度，检测波长多设为 214 nm，因为肽键在该波长有较强吸收。身份确认通常借助电喷雾电离质谱或串联质谱，将实测分子量与理论值逐项比对。序列层面可用肽图分析或氨基酸分析进一步验证。这些手段组合起来，可以分别覆盖纯度、身份与序列三个不同层次的信息。
Immune response – Nuclear actin polymerizes upon T-cell receptor stimulation and is required for cytokine expression and antibody production in vivo. DNA repair – Nuclear actin mediates the repair of DNA double-strand breaks. In the cell nucleus, a filamentous polymer of actin (F-actin) acts both in the DNA repair pathway of non homologous end joining and in the pathway of homologous recombinational repair. Due to its ability to undergo conformational changes and interaction with many proteins, actin acts as a regulator of formation and activity of protein complexes such as transcriptional complex.
Shaving or trimming (manually or with electric shavers which can be used on pubic hair or body hair) Depilatories (creams or "shaving powders" which chemically dissolve hair) Friction (rough surfaces used to buff away hair)
== Formation and ecological succession == Cold seeps occur over fissures on the seafloor caused by tectonic activity. Oil and methane "seep" out of those fissures, get diffused by sediment, and emerge over an area several hundred meters wide. Methane (CH4) is the main component of natural gas. But in addition to being an important energy source for humans, methane also forms the basis of a cold seep ecosystem. Cold seep biota below 200 m (660 ft) typically exhibit much greater systematic specialization and reliance on chemoautotrophy than those from shelf depths. Deep-sea seeps sediments are highly heterogeneous. They sustain different geochemical and microbial processes that are reflected in a complex mosaic of habitats inhabited by a mixture of specialist (heterotrophic and symbiont-associated) and background fauna.
== Types == Dosage forms vary depending on the method/route of administration, which can include many types of liquid, solid, and semisolid forms. Common dosage forms include tablets, capsules, drinks, solutions, suspensions, and syrups, among others. A combination drug (or fixed-dose combination; FDC) is a product that contains more than one active ingredient (e.g., one tablet, one capsule, or one syrup with multiple drugs). In naturopathy, dosages can take the form of decoctions and herbal teas, in addition to the more conventional methods mentioned above.
=== Energetic utilization === Various bacteria can utilize arginine as an energy source. It is initially converted by arginine deiminase into citrulline, then by ornithine transcarbamylase into ornithine and carbamoyl phosphate. One molecule of adenosine triphosphate can be generated from adenosine diphosphate through the breakdown of carbamoyl phosphate by carbamate kinase to ammonium hydrogen carbonate. Several prokaryotes use arginine as their sole energy source, including representatives of Mycoplasma, Bacillus, Spirochaeta, members of Halobacteria within the Archaea, as well as Streptococcus faecalis and Pseudomonas aeruginosa. However, this metabolic pathway also occurs in representatives of Aeromonas and Spiroplasma, other Pseudomonas species, as well as Clostridia and Cyanobacteria. Many bacteria utilizing this pathway excrete large amounts of ornithine, indicating that only guanidine is metabolized. In some bacteria, arginine can also serve as the sole nitrogen source, for example in Aeromonas formicans or Bacillus licheniformis. Another degradation pathway of arginine, observed for example in various Pseudomonas species, involves arginine succinyltransferase. In this pathway, the carbon atom of the arginine guanidino group is converted into carbon dioxide, and NADH is produced.
Sources: en.wikipedia.org
== Structural studies == As of late 2007, 9 structures have been solved for this class of enzymes, with PDB accession codes PDB: 1G6K, PDB: 1GCO, PDB: 1GEE, PDB: 1RWB, PDB: 1SPX, PDB: 2B5V, PDB: 2B5W, PDB: 2CD9, and PDB: 2CDA.
Additionally, FLAG-tags may be used in tandem, commonly the 3xFLAG peptide: DYKDHD-G-DYKDHD-I-DYKDDDDK (with the final tag encoding an enterokinase cleavage site). FLAG-tag can be fused to the C-terminus or the N-terminus of a protein, or inserted within a protein. Some commercially available antibodies (e.g., M1/4E11) recognize the epitope only when FLAG-tag is present at the N-terminus. However, other available antibodies (e.g., M2) are position-insensitive. The tyrosine residue in the FLAG-tag can be sulfated when expressed on certain secreted proteins, which can affect antibody recognition of the FLAG epitope. The FLAG-tag can be used in conjunction with other affinity tags, for example a polyhistidine tag (His-tag), HA-tag or myc-tag.
Liquids are useful as lubricants due to their ability to form a thin, freely flowing layer between solid materials. Lubricants such as oil are chosen for viscosity and flow characteristics that are suitable throughout the operating temperature range of the component. Oils are often used in engines, gear boxes, metalworking, and hydraulic systems for their good lubrication properties.
On 14 January, the United States Department of Energy announced that the United States had completed their first sales of Venezuelan oil valued at $500 million as part of a $2 billion deal between United States and Venezuela governments. On 15 January, Delcy Rodríguez announced that she was submitting a reform to the country's hydrocarbon law to "allow [foreign] investment flows to be incorporated into new fields, fields where no investment has ever been made and into fields where there is no infrastructure"; On 20 January, Delcy Rodríguez confirmed having received the first $300 million. She announced the money will go to the exchange market in Venezuela, the national banks and the central bank. Reuters indicated that the remaining $200 million were returned on 3 February according to anonymous United States officials. The proceeds from the sales were deposited in a Qatari bank account, preventing Venezuela's creditors from seizing them. Democrats questioned the legality of this arrangement, and criticized the lack of transparency in routing the funds. On 23 January, the first cargo of 460,000 barrels of naphtha by Vitol, necessary to deal with the heavy crude oil, arrived to Venezuela in a deal with the United States. Before that last cargo was received in December 2025 by Chevron Corporation in an agreement with the United States as the naval blockade had stopped many suppliers. On 28 January, Delcy Rodríguez announced that the United States was unfreezing various funds related to 2019 oil sanctions on Venezuela.
Sources: en.wikipedia.org
== Performance measures == The South African logistics sector ranks highly on a global scale, and rankings are continuing to increase. According to indices from the World Bank, as of 2026, SA's logistics infrastructure and performance are comparable to those of China and the United States. South Africa ranked joint 19th place, out of 139 countries in the 2023 World Bank Logistics Performance Index - an increase of 14 places year-over-year. There are various measures of performance for South African logistics, with a mix of indices, ranks, and other metrics from the a national and node-specific perspective. According to the Council for Scientific and Industrial Research, some of these are:
Brettanomyces (Teleomorph Dekkera) Candida (Teleomorphs for different species from several genera including Pichia, Metschnikowia, Issatchenkia, Torulaspora and Kluyveromyces) Kloeckera (Teleomorph Hanseniaspora), usually the most common "wild yeast" found in the vineyard. Some species are known as "killer yeast" that produce inhibitory levels of ethyl acetate and acetic acid that can kill off sensitive strains of Saccharomyces cerevisiae Saccharomycodes Schizosaccharomyces, the only wine yeast that reproduced by fission whereas most wine yeast reproduce by budding. Zygosaccharomyces, very alcohol-tolerant and can grow in wines up to 18% v/v. Additionally this yeast can survive in extremely high sugar levels (as much as 60% w/w or 60 Brix) and is very resistant to sulfur dioxide. Aureobasidium, particularly the "black yeast" species of Aureobasidium pullulans found in moist cellars that can contaminate aging wine in barrels.
Rennie, the British commissioner in Allenstein, reported on 11 March 1920, that "in those parts which touch the Polish frontier a vigorous German propaganda is in progress" and that "the Commission is doing all it can to prevent German officials in the district from taking part in national propaganda in connection with the Plebiscite. Ordinances and instructions in this sense have been issued".
The diver needs to stay on the bottom to work some of the time, and may need to have neutral buoyancy some of the time. The diving suit is usually buoyant, so added weight is usually necessary. This can be provided in several ways. Unwanted positive buoyancy is dangerous to a diver who may need to spend significant time decompressing during the ascent, so the weights are usually attached securely to prevent accidental loss.
3 H2N-CO-NH2 → [C(O)NH]3 + 3 NH3 CYA crystallizes from water as the dihydrate. Cyanuric acid can be produced by hydrolysis of crude or waste melamine followed by crystallization. Acid waste streams from plants producing these materials contain cyanuric acid and on occasion, dissolved amino-substituted triazines, namely, ammeline, ammelide, and melamine. In one method, an ammonium sulfate solution is heated to the "boil" and treated with a stoichiometric amount of melamine, by which means the cyanuric acid present precipitates as melamine-cyanuric acid complex. The various waste streams containing cyanuric acid and amino-substituted triazines may be combined for disposal, and during upset conditions undissolved cyanuric acid may be present in the waste streams.
Sources: en.wikipedia.org
It has not been approved as a therapeutic by major regulators, and the human trial record is small and dated. Material available today is mostly sold as a research chemical for laboratory use. Approval and restriction status varies by country.
It binds the ghrelin receptor, known as the growth hormone secretagogue receptor type 1a. Activation of that receptor triggers signaling that leads to growth hormone release. Selectivity for growth hormone over cortisol and prolactin is the property most often cited for this compound.
Published estimates place the circulating half-life at roughly two hours in humans. Clearance involves peptidase activity and renal handling. Because the peptide is short-lived, release patterns after administration are usually described as pulsatile rather than sustained.
It is a synthetic pentapeptide in the growth hormone secretagogue family and acts as an agonist at the ghrelin receptor. It is handled as a laboratory research compound rather than a naturally occurring hormone.