The short version of GHS-R1a fits in a sentence. The long version — which is the one that helps — is below.
This page was last updated on 2026-06-06 and is reviewed periodically as new material appears.
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.
Selectivity distinguishes ipamorelin from first-generation secretagogues such as GHRP-6. At doses that reliably raise growth hormone, it shows little stimulation of adrenocorticotropic hormone or cortisol release in animal models, and it does not markedly raise prolactin or appetite. Binding at GHS-R1a on pituitary somatotrophs triggers calcium influx and pulsatile growth hormone secretion. Because the compound mimics the natural ghrelin signal, the release pattern tends to follow the body's own rhythm rather than producing a sustained elevation.
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.
Peptides such as ipamorelin are subject to chemical and physical degradation. Hydrolysis of peptide bonds, oxidation of susceptible residues, and aggregation are common pathways that reduce purity over time. The rate of these processes depends on temperature, moisture, pH, and the number of freeze-thaw cycles a sample undergoes. Because the compound is typically handled as a lyophilized powder, controlling moisture during storage is a central concern. Degradation products can be detected with separation techniques that resolve the parent peptide from related impurities.
Lyophilized material is generally stored frozen and protected from light and moisture. Typical recommendations place dry powder at temperatures well below freezing, while reconstituted solutions are kept cold and used within a defined window. Repeated freezing and thawing should be avoided because it can promote aggregation and loss of material. The choice of solvent matters as well; compatibility with the intended diluent should be checked before preparation. These handling practices aim to preserve both the quantity and the integrity of the peptide.
Verification of identity and purity relies on analytical methods used across peptide chemistry. Reverse-phase high-performance liquid chromatography separates components by hydrophobicity and provides a purity estimate. Mass spectrometry confirms molecular mass and helps detect modifications. Together these techniques give complementary information about whether a sample matches its expected structure. Results depend on method parameters and reference standards, so reported purity values are meaningful only when the analytical conditions are stated. Consistency between laboratories requires comparable protocols and well-characterized reference materials.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Includes two non-natural residues |
| Molecular weight | About 711.9 g/mol | Confirmed by mass spectrometry |
| Appearance | White to off-white powder | Typical lyophilized form |
| Receptor target | GHS-R1a | Ghrelin receptor agonist |
| Plasma half-life | Roughly 2 hours | Varies by species and assay |
The compound was developed at Novo Nordisk during the 1990s as part of a programme seeking secretagogues with improved selectivity. It was described in the peer-reviewed literature in 1998 alongside related pentapeptides from the same series. Investigators advanced it because it raised growth hormone output in animal models while leaving other pituitary hormones comparatively unaffected. The development code NNC 26-0161 appears in earlier reports, and ipamorelin later became the common designation in published work.
Selectivity is the property most often attached to this peptide. Published animal and early human studies record increases in growth hormone release after administration, with adrenocorticotropic hormone and cortisol responses remaining small by comparison. Effects on appetite-related pathways also appear weaker than those reported for several earlier secretagogues. Reviews that compare members of the growth hormone secretagogue family cite these findings frequently, though the receptor-level explanation for the selectivity continues to be debated rather than settled.
Published discussion of this compound is uneven. Some references describe it as a tool for probing growth hormone regulation, while others focus on analytical characterization or on comparisons with related secretagogues. Statements about selectivity, half-life and potency often trace back to a small number of original reports that later authors cite secondhand. Readers evaluating a claim should therefore check whether a figure reflects a direct measurement or a repeated citation, and whether the underlying study was conducted in animals, in isolated cells or in human volunteers.
Identity and purity assessment for a research peptide of this kind typically combines reversed-phase high-performance liquid chromatography with mass spectrometry. The chromatographic run separates related impurities and yields a purity percentage, while electrospray ionization or matrix-assisted laser desorption mass spectrometry confirms the expected molecular mass. Amino acid analysis or tandem mass spectrometry sequencing can add confidence when material is intended for quantitative work. Laboratories differ in how they calculate and report purity, so figures from different sources are not always directly comparable.
Lyophilized material is generally stored cold and dry, with desiccant, and protected from light. In solution the peptide is more vulnerable: the histidine side chain can oxidize, and repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. A mildly acidic aqueous buffer is often used for short-term handling because it limits several degradation routes. Accurate prediction of long-term stability under a given set of conditions is difficult, and published stability data remain sparse.
=== Acting roles === Flay had a cameo appearance in the Disney Channel original movie Eddie's Million Dollar Cook-Off as the host of the cook-off. He appeared on the television game show Pyramid with fellow Iron Chef Mario Batali as the guest celebrities in an episode originally airing on November 18, 2003. He appeared as a judge on the CBS television show "Wickedly Perfect" during the 2004–05 season. He also appeared in the Law & Order: Special Victims Unit episode "Design", which originally aired on September 22, 2005. He had a small role as himself in the 2006 film East Broadway, in which his then-wife, Stephanie March, had a larger role. Jeopardy! featured a special "Throwdown with Bobby Flay" category during the March 12, 2008, episode, in which each of the clues featured Flay. He participated in the 2008 Taco Bell All-Star Legends and Celebrity Softball Game played at Yankee Stadium after the 2008 MLB All Star Game; Flay played for the National League. Flay is mentioned in the 2008 film Step Brothers in the "Derek comes for dinner" scene. In 2010, Flay was impersonated in the South Park cartoon episode "Crème Fraiche". In 2011, Flay had recurring appearances in the final season of Entourage as the boyfriend of Ari Gold's wife. In 2012, Flay appeared on Portlandia in a director's cut of the episode Brunch Village in which he showed director Jonathan Krisel how to make marionberry pancakes. Flay guest stars as himself on season two of the TV series Younger, which initially aired in 2016.
=== Applications for ecosystem process analysis === Isotopic tracers are used to examine processes in natural systems, especially terrestrial and aquatic environments. In soil science 15N tracers are used extensively to study nitrogen cycling, whereas 13C and 14C, stable and radioisotopes of carbon respectively, are used for studying turnover of organic compounds and fixation of CO2 by autotrophs. For example, Marsh et al. (2005) used dual labeled (15N- and 14C) urea to demonstrate utilization of the compound by ammonia oxidizers as both an energy source (ammonia oxidation) and carbon source (chemoautotrophic carbon fixation). Deuterated water is also used for tracing the fate and ages of water in a tree or in an ecosystem.
Mary Osborn (born in 1940) is a L'Oréal-UNESCO Women in Science Award-winning English cell biologist who, until she stopped running an active laboratory in 2005, was on the scientific staff at the Max Planck Institute for Biophysical Chemistry, Göttingen, Germany. Osborn established two techniques frequently used by cell biologists. She pioneered both molecular weight determination of proteins using SDS PAGE and immunofluorescence microscopy. Osborn also used the immunofluorescence microscopy method to work out the details of the eukaryotic cytoskeleton. Small differences in the intermediate filament constituents helped her distinguish differentiated cells from each other. She also found intermediate filament immunofluorescence differences between normal versus cancer cells. Mary Osborn has been a prominent spokesperson for women in science.
Sources: en.wikipedia.org
== External links == The MEROPS online database for peptidases and their inhibitors: I39.001[link removed] alpha+2-Macroglobulin at the U.S. National Library of Medicine Medical Subject Headings (MeSH) A2M human gene location in the UCSC Genome Browser. A2M human gene details in the UCSC Genome Browser.
== Mechanism of action == Both dalfopristin and quinupristin bind to sites located on the 50S subunit of the ribosome. Initial dalfopristin binding results in a conformational change of the ribosome, allowing for increased binding by quinupristin. A stable drug-ribosome complex is created when the two drugs are used together. This complex inhibits protein synthesis through prevention of peptide-chain formation and blocking the extrusion of newly formed peptide chains. In many cases, this leads to bacterial cell death.
Endocrine glands secrete their product into the extracellular space where it is rapidly taken up by the circulatory system. Exocrine glands secrete their products into a duct that then delivers the product to the lumen of an organ or onto the free surface of the epithelium. Their secretions include tears, saliva, oil (sebum), enzyme, digestive juices, sweat.
=== Diabetes mellitus === GCK mutations reduce the functional efficiency of the glucokinase molecule. Heterozygosity for alleles with reduced enzyme activity results in a higher threshold for insulin release and persistent, mild hyperglycemia. This condition is referred to as maturity onset diabetes of the young, type 2 (MODY2). The most recent overview of GCK mutation that were observed in patients claims 791 mutations, of which 489 are thought to cause the MODY diabetes and therefore reduce the functional efficiency of the glucokinase molecule. Homozygosity for GCK alleles with reduced function can cause severe congenital insulin deficiency, resulting in persistent neonatal diabetes.
Sources: en.wikipedia.org
The peptide is Aib-His-D-2-Nal-D-Phe-Lys-NH2. Two of its residues are non-natural, which slows enzymatic degradation. The C-terminal amide is common among bioactive peptides.
It binds the same ghrelin receptor but with greater selectivity in functional assays. Preclinical work reports less cortisol and prolactin stimulation at growth-hormone-releasing doses. Those differences are relative, not absolute, and depend on dose and model.
No major regulatory authority has approved it for human therapeutic use. It is sold as a research chemical for laboratory investigation. Clinical status varies by country and is subject to change.
Dry powder is typically kept frozen, desiccated, and protected from light. Avoiding moisture exposure and large temperature swings helps slow degradation. Storage recommendations vary by supplier and should be followed for the specific material.