If you have been reading about GHS-R1a 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.
Updated 2026-01-16. Numbers and descriptions here follow the published literature rather than marketing material.
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.
At the cellular level, ipamorelin binds the growth hormone secretagogue receptor, also called the ghrelin receptor. Activation of this receptor on pituitary somatotroph cells triggers a signaling cascade that leads to release of growth hormone into circulation. Because release follows a pulsatile pattern, studies often report peak concentration and total area under the curve rather than a single time point. Selectivity for this receptor is the property most frequently discussed in comparative work.
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.
Lyophilized ipamorelin is generally held at minus twenty degrees Celsius or colder, protected from light and moisture. In solution the peptide is less stable, and degradation proceeds through hydrolysis of the amide backbone, oxidation of the histidine residue, and aggregation. Repeated freeze-thaw cycles accelerate these processes, so dividing material into single-use aliquots before freezing is common practice in research settings. Buffered formulations near neutral pH tend to show the slowest degradation, while strongly acidic or basic conditions raise hydrolysis rates. Stability data specific to ipamorelin are sparse, and much guidance is extrapolated from other short peptides.
Quality control for research-grade ipamorelin is not governed by a single harmonized pharmacopeial monograph, so certificates of analysis vary between suppliers. Common tests include appearance, solubility, water content, peptide content by quantitative amino acid analysis, and residual counterion measurement. Independent verification by an outside laboratory is often used to confirm identity and purity claims. Salt form, counterion content, and residual solvent levels are frequently unspecified, which complicates direct comparison between lots and leaves reproducibility partly unresolved.
Identity and purity assessment of ipamorelin relies mainly on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometers, a wavelength where the peptide backbone absorbs. Mass confirmation is typically obtained by electrospray ionization mass spectrometry or by liquid chromatography coupled to mass spectrometry, comparing the observed mass with the calculated value. Amino acid analysis and peptide mapping after enzymatic digestion can confirm the sequence. Impurity profiles include deletion peptides, truncated fragments, and oxidation products, reported as relative area percentages.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic pentapeptide | Growth hormone secretagogue family |
| Sequence | Aib-His-D-2-Nal-D-Phe-Lys-NH2 | Contains two non-natural residues |
| Molecular formula | C38H49N9O5 | Free base form |
| Molecular weight | 711.85 g/mol | Calculated from formula |
| Primary target | GHS-R1a ghrelin receptor | Agonist activity |
In the scientific literature, ipamorelin appears mainly in preclinical studies, receptor binding assays, and reviews of growth hormone secretagogues. Authors often discuss its selectivity profile alongside limitations such as small sample sizes, short study durations, and differences between species. Some papers examine pharmacokinetics and clearance, but human data are limited and not sufficient to define general clinical effects. Regulatory discussion treats the compound as an investigational or research substance rather than an approved therapy in most jurisdictions. Open questions include oral bioavailability, long-term endocrine effects, and whether selectivity observed in animals persists in humans.
Research peptides such as ipamorelin are commonly supplied as lyophilized powder and characterized by analytical certificates. Reversed-phase high-performance liquid chromatography is used to estimate purity by ultraviolet absorbance, while mass spectrometry confirms molecular identity and detects sequence-related impurities. Counterion content, water content, and residual synthesis reagents can affect the reported mass balance. A certificate of analysis may list a purity percentage, but that number depends on the analytical method and the definition of impurity peaks. Independent verification is often recommended because research supply chains vary in quality control practices.
Storage recommendations for ipamorelin usually focus on temperature, moisture, and light. Lyophilized powder is typically held at or below minus twenty degrees Celsius in a desiccated container protected from light. Reconstituted solutions are often aliquoted and stored at minus eighty degrees Celsius to reduce repeated freeze-thaw cycles, which can promote aggregation or degradation. The optimal buffer and pH depend on the specific assay, and no single condition applies to every experimental context. Peptide stability should be assessed with time-point measurements rather than assumed from general handling rules.
现有文献多来自小规模、短期的研究，涉及生长激素缺乏、术后肠麻痹等方向。长期使用是否导致受体脱敏，以及重复给药后效应是否衰减，仍属开放问题。不同研究之间的剂量、给药途径和受试者特征差异较大，因此结论外推需谨慎。关于临床获益的确切证据尚不充分，需要更大规模的对照试验来澄清。
Ipamorelin 是一种合成五肽，在 20 世纪 90 年代被报道为生长激素促分泌剂。其结构基于胃饥饿素受体激动剂的设计思路，但并非天然激素。早期药理学研究显示，它可刺激垂体释放生长激素，而对应激激素轴的影响相对较小。该化合物常被用作研究生长激素调节通路的工具分子。
==== International ==== DET is listed under Schedule I of the United Nations 1971 Convention on Psychotropic Substances, placing it under international control. This means that countries that are parties to the Convention are required to regulate DET production, distribution, and use, restricting it to scientific and very limited medical purposes. Possession and trade of DET without appropriate authorization is prohibited under international law.
=== Culinary === Also known as "poor man's saffron", the petals are edible and can be used fresh in salads or dried and used to color cheese or as a substitute for saffron. Calendulas have a mildly sweet taste that is slightly bitter, and as it dries these flavors become more intense. It can be used to add color to soups, stews, poultry dishes, custards and liquors. The common name for Calendula officinalis in Britain is 'pot-marigold', named so because of its use in broths and soups.
==== Refrigeration ==== Food storage in refrigerators may not be safe unless there is close adherence to temperature guidelines. In general, the temperature should be maintained at 4 °C (39 °F) or below, but never below 1 °C (34 °F). Safe storage times vary by food and may depend on how the food was handled before being placed in the refrigerator.
== Y == Yam – indigenous Americans in the Guyana region of South America domesticated the most important New World yam: D. Trifada Yucca – the plant was cultivated throughout the Americas, and is mostly distributed in coastal lowlands and dry beach scrub of coastal areas.
Sources: en.wikipedia.org
=== East vs West === The dissonance between Japanese tradition and Western modernity is present throughout the novel. Kaname's aesthetic tastes lean more toward the West. His romanticized version of it is manifested in the western wing of his house, in particular the veranda on which he likes to sit, in his fascination with American movie stars, and in his skimming through an English translation of the Arabian Nights for lewd passages. However, after a visit to the bunraku theater with his wife, his father-in-law, and his father-in-law's mistress in Chapter Two, Kaname's interest in traditional aesthetics is piqued, and he even becomes envious of the "old man" and his lifestyle: watching an old play, pipe in hand, sake and a young mistress at his side. This is the beginning of Kaname's divergent interest in the East, his preference for the past.
Additional design elements are common among contemporary In-N-Out locations. Matching In-N-Out's California-inspired palm tree theme, palm trees are sometimes planted to form an "X" in front of the restaurants. This is an allusion to founder Harry Snyder's favorite movie, Stanley Kramer's It's a Mad, Mad, Mad, Mad World, in which the characters look for a hidden treasure and find it under "the big W" made by four palm trees, with the middle two forming an "X".
=== Laminin EGF-like === Beside different types of globular domains each laminin subunit contains, in its first half, consecutive repeats of about 60 amino acids in length that include eight conserved cysteines. The tertiary structure of this domain is remotely similar in its N-terminus to that of the EGF-like module. It is also known as a 'LE' or 'laminin-type EGF-like' domain. The number of copies of the laminin EGF-like domain in the different forms of laminins is highly variable; from 3 up to 22 copies have been found. In mouse laminin gamma-1 chain, the seventh LE domain has been shown to be the only one that binds with a high affinity to nidogen. The binding-sites are located on the surface within the loops C1-C3 and C5-C6. Long consecutive arrays of laminin EGF-like domains in laminins form rod-like elements of limited flexibility, which determine the spacing in the formation of laminin networks of basement membranes.
mixture A material made up of two or more different substances which are mixed physically but are not combined chemically (i.e. a chemical reaction has not taken place which has changed the molecules of either substance into new substances).
== Destaining == Proteins which were separated by 1D or 2D PAGE are usually visualised by staining with dyes like Coomassie brilliant blue (CBB) or silver. Although the sensitivity of the method is significantly lower, the use of Coomassie is more common for samples destined for mass spectrometry since the silver staining impairs the analysis. After excision of the protein band of interest from the gel most protocols require a destaining of the proteins before proceeding. The destaining solution for CBB contains usually the buffer salt ammonium bicarbonate (NH4HCO3) and a fraction of 30%-50% organic solvent (mostly acetonitrile). The hydrophobic interactions between protein and CBB are reduced by the organic fraction of the solution. At the same time, the ionic part of the solution diminishes the electrostatic bonds between the dye and the positively charged amino acids of the protein. In contrast to a mixture of water with organic solvent the effectivity of destaining is increased. An increase of temperature promotes the destaining process. To a certain degree (< 10%) the destaining procedure is accompanied with a loss of protein. Furthermore, the removal of CBB does not affect the yield of peptides in the mass spectrometric measurement. In the case of silver stained protein bands the destaining is accomplished by oxidation of the metallic silver attached to the protein by potassium ferricyanide or hydrogen peroxide (H2O2). The released silver ions are complexed subsequently by sodium thiosulfate.
Sources: en.wikipedia.org
It is a synthetic pentapeptide in the growth hormone secretagogue family. The chain contains five residues, two of which are non-natural amino acids.
It acts as an agonist at the growth hormone secretagogue receptor, also known as the ghrelin receptor. Binding at pituitary somatotroph cells promotes growth hormone release.
Early studies report weaker effects on cortisol, prolactin, and appetite than compounds such as GHRP-6. The size of that difference in humans is not firmly established.
The standard approach is reversed-phase high-performance liquid chromatography, with purity reported as the relative area of the main peak. Ultraviolet detection near 214 nanometers is typical for peptides. Mass spectrometry is added to confirm identity rather than to quantify purity.