This is a working overview of GHS-R1a, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-04. Anything still debated is marked as such rather than presented as settled.
Activity is mediated mainly through the growth hormone secretagogue receptor, now generally called the ghrelin receptor or GHS-R1a. Binding at this G-protein-coupled receptor triggers phospholipase C signaling, calcium mobilization, and release of growth hormone from pituitary somatotrophs. Reports describe less pronounced stimulation of adrenocorticotropic hormone and prolactin compared with earlier secretagogues such as hexarelin or GHRP-6. Selectivity figures vary between assay systems, so the degree of separation from other secretagogues is an area of ongoing comparison rather than a fixed constant.
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.
Compared with earlier growth hormone secretagogues such as GHRP-6 and hexarelin, ipamorelin has been reported to produce less stimulation of adrenocorticotropic hormone, cortisol, and prolactin in animal and early human studies. This selectivity is usually attributed to differences in receptor subtype interactions and to the tissue distribution of the receptor. Effects on appetite appear weaker than those of ghrelin itself, although the supporting evidence base is small. Whether these differences produce a distinct clinical profile remains an open question, since controlled human trials are limited.
Ipamorelin is a synthetic pentapeptide first described in the 1990s by researchers at Novo Nordisk during a program to develop selective growth hormone secretagogues. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, incorporating two non-natural residues, alpha-aminoisobutyric acid and D-2-naphthylalanine. The C-terminus is amidated, and the material is supplied as a white lyophilized powder. The molecular formula is C38H49N9O5 and the monoisotopic mass is approximately 711.85 daltons. The short chain and modified residues give it greater resistance to enzymatic degradation than many larger peptide hormones.
| Property | Value | Notes |
|---|---|---|
| Peptide class | Synthetic pentapeptide | GHS-R1a agonist family |
| Receptor target | Ghrelin receptor (GHS-R1a) | G-protein-coupled receptor |
| Sequence length | Five amino acid residues | Includes non-natural residues |
| Primary reported output | Pulsatile growth hormone release | Observed in animal and early human work |
| Molecular formula | C38H49N9O5 | Corresponds to roughly 711.9 g/mol |
Compared with older secretagogues such as hexarelin or GHRP-6, ipamorelin shows weaker stimulation of cortisol, prolactin, and appetite in the animal models used for early characterization. Whether that selectivity is preserved across longer human exposures remains an open question, because published clinical data are limited in size and duration. Reported effects on food intake are generally described as modest. The compound is therefore treated in the literature as a relatively selective research tool rather than a fully characterized therapeutic agent.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class of compounds. Researchers at a pharmaceutical company first described it in the 1990s while screening small peptides for growth hormone releasing activity. Its chain contains five amino acid residues, two of which are non-natural building blocks, including 2-aminoisobutyric acid and a naphthylalanine derivative. The molecule was designed to act at the ghrelin receptor while avoiding several effects observed with earlier secretagogues.
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.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class. It acts as an agonist at the ghrelin receptor, also called the growth hormone secretagogue receptor type 1a. The compound was designed in the 1990s during a search for agents that release growth hormone with fewer off-target hormonal effects than earlier secretagogues. It appears in the research literature under several sequence-based names. Material supplied for laboratory work is normally a lyophilized solid, and it is not marketed as an approved therapeutic in major jurisdictions.
Most published work on ipamorelin comes from rodent studies and small early-phase human trials. Subcutaneous and intravenous routes have been used, while oral delivery is limited by poor absorption and rapid breakdown in the gut. The reported plasma half-life is short, on the order of two hours, and varies with species and assay method. Whether chronic use produces meaningful clinical benefit remains unresolved, and long-term safety data in humans are sparse. No major regulatory agency has approved the compound as a therapeutic drug.
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, incorporating two non-natural residues that resist enzymatic breakdown. Researchers at Novo Nordisk described the compound in the 1990s while searching for agents that release growth hormone with fewer side effects than earlier secretagogues. The molecule acts as an agonist at the ghrelin receptor, also called GHS-R1a, which is expressed in the pituitary and in several peripheral tissues.
从用途定位看，ipamorelin 目前主要以研究用肽的身份被讨论，未见主要药品监管机构将其批准为治疗药物。市售材料通常标注仅供研究使用，不得用于人体或诊断程序。文献中它常与生长激素促分泌素、GHS-R1a 激动剂、胃饥饿素拟似物等表述并列出现。既有研究的样本量普遍偏小，因此对其效应强度与一致性的描述应保持谨慎。
Ipamorelin 是一种合成五肽，序列为 Aib-His-D-2-Nal-D-Phe-Lys-NH2，分子式 C38H49N9O5，游离碱分子量约 711.85 g/mol。它属于生长激素促分泌素（GHS）家族，作用靶点是胃饥饿素受体 GHS-R1a。该化合物由诺和诺德的研究团队在二十世纪九十年代末报道，设计目标是提高对生长激素释放的选择性。C 端酰胺化与 N 端 Aib 残基是两个用于抵抗肽酶降解的结构特征。
The alcohol 3 was then converted into the acetate 4 via acetic anhydride-pyridine at room temperature with an overall yield of 90%. The acetate was then converted to the hydroxymethyl derivative 5 in three steps (1. TFA/room temperature; 2. ClCO2Et/Et3N-CH2Cl2/room temperature; 3. NaBH4/CH3OH-CH2Cl2/0 °C. Mesylation of 5 (MsCl/CH3OH-Et3N-CH2Cl2/0 °C), followed by lithium chloride treatment in DMF and hydrolysis (NaOCH3/CH3OH-CH2Cl2/room temperature) give the chloride 6 at a 95% overall yield. Adding phenyllithium slowly to a mixture of 6 and chloromethyl benzyl ether in excess in THF at 78 °C gave the benzylgliotoxin adduct 7 at 45% yield. Next, boron trichloride treatment of 7 in in methylene chloride at 0 °C yielded the gliotoxin anisaldehyde adduct 8 at 50% yield. Finally, acid oxidation of 8 followed by perchloric acid treatment in methylene chloride at room temperature yielded d,l-gliotoxin in a 65% yield. Spectroscopic analysis (NMR, ir, uv, MS) and TLC comparison showed that the synthetic substance was identical to natural gliotoxin. At least a couple of alternative syntheses are known to be reported in the pendant literature.
=== Honours === House of Habsburg: Grand Mistress Dame of the Order of the Starry Cross Dame Grand Cross of the Order of Elisabeth, 1913 Knight Grand Officer of the Order of the Red Cross, with War Decoration Sovereign Military Order of Malta: Dame Grand Cross of Honour and Devotion of the Order of Saint John
== Production and use == Nitrilotriacetic acid is commercially available as the free acid and as the sodium salt. It is produced from ammonia, formaldehyde, and sodium cyanide or hydrogen cyanide. NTA is also cogenerated as an impurity in the synthesis of EDTA, arising from reactions of the ammonia coproduct. Older routes to NTA included alkylation of ammonia with chloroacetic acid and oxidation of triethanolamine.
The gastrin-releasing peptide receptor (GRPR), now properly known as BB2 is a G protein-coupled receptor whose endogenous ligand is gastrin releasing peptide. In humans it is highly expressed in the pancreas and is also expressed in the stomach, adrenal cortex and brain. Gastrin-releasing peptide (GRP) regulates numerous functions of the gastrointestinal and central nervous systems, including release of gastrointestinal hormones, smooth muscle cell contraction, and epithelial cell proliferation and is a potent mitogen for neoplastic tissues. The effects of GRP are mediated through the gastrin-releasing peptide receptor. This receptor is a glycosylated, 7-transmembrane G-protein coupled receptor that activates the phospholipase C signaling pathway. The receptor is aberrantly expressed in numerous cancers such as those of the lung, colon, and prostate. An individual with autism and multiple exostoses was found to have a balanced translocation between chromosome 8 and an X chromosome breakpoint located within the gastrin-releasing peptide receptor gene. The transcription factor CREB is a regulator of human GRP-R expression in colon cancer. Activation MOR1D‐GRPR heteromers in the spinal cord mediate the common troublesome opioid-induced itch.
The Reconquista was a series of military and cultural campaigns by northern Iberian Christian polities against al-Andalus. The death of the Umayyad emir Abd ar-Rahman II in 852 brought an end to Umayyad efforts to extend authority northward. The discovery in the 830s of a tomb believed to be that of James the Great gave the Christians a powerful patron, and the elevation of Alfonso III of Asturias in the 860s ended a period of uncertain leadership, thereby providing the command required to channel this energy into a wave of expansionism southward. In 868, the region between the Minho and Douro rivers was secured from the Moors by Christian forces under Vímara Peres and constituted as the County of Portugal under him. The first county of Portugal lasted until 1071. In 1096, Alfonso VI of León refounded the county and bestowed it on Henry of Burgundy, who married Alfonso's illegitimate daughter, Teresa of León.
Sources: en.wikipedia.org
=== Blended malt === Blended malt whisky, formerly called vatted malt or pure malt (terms that are now prohibited in the SWR 2009), is one of the least common types of Scotch: a blend of single malts from more than one distillery (possibly with differing ages). Blended malts contain only single malt whiskies from two or more distilleries. This type must contain no grain whiskies and is distinguished by the absence of the word "single" on the bottle. The age of the vat is that of the youngest of the original ingredients. For example, a blended malt marked "8 years old" may include older whiskies, with the youngest constituent being eight years old. Johnnie Walker Green Label and Monkey Shoulder are examples of blended malt whisky. Starting from November 2011, no Scotch whisky could be labelled as a vatted malt or pure malt, the SWR requiring them to be labelled blended malt instead.
==== Half-Life 2: Lost Coast (2005) and Team Fortress 2 (2007) ==== Antonov worked on Half-Life 2: Lost Coast, an additional level for Half-Life 2 released in 2005 as a free download for owners of the game. His last credit at Valve was for the online multiplayer FPS Team Fortress 2 (2007), temporarily working as its art director until his friend Moby Francke joined the company, at which point Antonov handed the role to him. Antonov left the company in 2006. He later explained that he was disappointed he had "spent six years of my life on one single project", and he did not care to work on small-scale episodic games, which Valve made with Half-Life 2: Episode One (2006) and Episode Two (2007). He wanted to make more "AAA" games like the original Half-Life 2, at a job in Europe which gave more artistic independence and "maneuverability" than Valve.
=== Aminopeptidase === The aminopeptidase test analyzes bacteria for the production of the enzyme L-alanine-aminopeptidase, an enzyme found in many gram-negative bacteria. Adding L-Alanine-4-nitroanilide hydrochloride to a bacterial culture works as an indicator, changing to a yellow color in the presence of L-alanine-aminopeptidase.
The head is as large as an ordinary flour barrel, and has the shape of a sea lion head. The neck, if the creature may be said to have a neck, is of the same diameter as the body. The mouth is on the underside of the head and is protected by two tentacle tubes about eight inches in diameter and about 30 feet long. These tubes resemble an elephant's trunk and obviously were used to clutch in a sucker like fashion any object within their reach. Another tube or tentacle of the same dimensions stands out on the top of the head. Two others, one on each side, protrude from beyond the monster's neck, and extend fully 15 feet along the body and beyond the tail. The tail, which is separated and jagged with cutting points for several feet, is flanked with two more tentacles of the same dimensions as the others and 30 feet long. The eyes are under the back of the mouth instead of over it. This specimen is so badly cut up by sharks and sawfish that only the stumps of the tentacles remain, but pieces of them were found strewn for some distance on the beach, showing that the animal had a fierce battle with its foes before it was disabled and beached by the surf. Grant describes the animal as having seven "tentacles" and a "tail". If the "tail" is interpreted as another tentacle, giving a total of eight, this would suggest an octopus as opposed to a decapod, such as the squid or cuttlefish. Furthermore, nothing in the description indicates the presence of the long feeding tentacles found in squid, as the "tentacles" are said to be of the same dimensions.
== Production == Hexane is chiefly obtained by refining crude oil. The exact composition of the fraction depends largely on the source of the oil (crude or reformed) and the constraints of the refining. The industrial product (usually around 50% by weight of the straight-chain isomer) is the fraction boiling at 65–70 °C (149–158 °F).
Sources: en.wikipedia.org
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.
Studies generally report growth hormone as the dominant output, with smaller or absent effects on adrenocorticotropic hormone and prolactin. The size of that separation depends on the assay and the dose examined, so it is best described as relative selectivity.
No natural source has been identified, and the molecule is produced by chemical synthesis. Its non-natural residues distinguish it from endogenous ghrelin even though both engage the same receptor.
It is a synthetic pentapeptide belonging to the growth hormone secretagogue family. Its principal characterized target is the ghrelin receptor, also called GHS-R1a. The molecule contains non-natural amino acids and an amidated C-terminus.