This is a working overview of Ipamorelin, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-01-26 and is reviewed periodically as new material appears.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Pentapeptide with C-terminal amide |
| Average mass | Approximately 711.9 Da | Value derived from the formula |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water and aqueous acetonitrile | Dissolution aided by acidic diluents |
| Common synonyms | Ipamorelin; NNC 26-0161 | Code name used in early reports |
At the molecular level, ipamorelin acts as an agonist at the growth hormone secretagogue receptor type 1a, the same G protein-coupled receptor that binds ghrelin. Receptor activation couples to Gq/11 signaling, raising intracellular calcium through inositol trisphosphate and diacylglycerol, which in turn promotes exocytosis of growth hormone from pituitary somatotroph cells. Ipamorelin binds this receptor with high affinity and shows weak activity at other secretagogue-related targets in vitro. Its action requires the intact receptor and is not reversed by growth hormone-releasing hormone antagonists.
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.
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.
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.
== Preparations == The Gemini 4 spacecraft completed major manufacturing activity, module tests, and equipment installation at McDonnell at the end of January 1965. The spacecraft was mated to the Titan II launch vehicle at Cape Canaveral Launch Complex 19 on April 23, 1965. Final system tests were performed over several additional weeks. NASA leadership approved the Gemini 4 EVA plan on May 25, 1965; the public was informed on the same day
Newsom was sworn in on January 7, 2019. Several recall attempts were launched against Newsom early in his tenure but failed to gain much traction. On February 21, 2020, a recall petition was introduced by Orrin Heatlie, a deputy sheriff in Yolo County. The petition mentioned Newsom's sanctuary state policy and said laws he endorsed favored "foreign nationals, in our country illegally"; said that California had high homelessness, high taxes, and low quality of life; and described other grievances. The California secretary of state approved it for circulation on June 10, 2020. Forcing the gubernatorial recall election required a total of 1,495,709 verified signatures. By August 2020, 55,000 signatures were submitted and verified by the secretary of state, and 890 new valid signatures were submitted by October 2020. The petition was initially given a signature deadline of November 17, 2020, but it was extended to March 17, 2021, after Judge James P. Arguelles ruled that petitioners could have more time because of the pandemic. Newsom's attendance at a party at The French Laundry in November 2020, despite his public health measures; voter anger over lockdowns, job losses, school and business closures; and a $31 billion fraud scandal at the state unemployment agency were credited for the recall's growing support.
The aquaporins (AQPs) are water selective. The aquaglyceroporins are permeable to water, but also to other small uncharged molecules such as glycerol. The third subfamily, with little conserved amino acid sequences around the NPA boxes, include 'superaquaporins' (S-aquaporins). The phylogeny of insect MIP family channels has been published.
Sources: en.wikipedia.org
== Clinical significance == Maleylacetoacetate isomerase deficiency is a disease caused by a mutation in the gene GSTZ1. This is an autosomal recessive inborn error of metabolism. It is caused by a mutation in the gene that codes for the synthesis of 4-maleylacetoacetate isomerase, GSTZ1. Mutations in 4-maleylacetoacetate isomerase resulted in accumulation of fumarylacetoacetate and succinylacetone in the urine, but individuals were otherwise healthy. It is likely that there exists an alternate nonenzymatic bypass that allows the catabolism of 4-maleylacetoacetate in the absence of 4-maleylacetoacetate isomerase. Because of this mechanism, a mutation in the gene encoding 4-Maleylacetoacetate isomerase is not considered dangerous. GSTZ1 is highly expressed in the liver, however mutations in this gene do not impair liver function or coagulation.
== Personal history == Huggins was born in 1897 to Amos Williamson Huggins and Mary Abigail Hackley. He had at least two sisters, Dorothea Harriet Huggins (born September 22, 1894) and Mary Abigail Huggins (born October 2, 1904). He earned his Ph.D. in 1922 under Charles Walter Porter (known as Walter Porter) in the Chemistry Laboratory of the University of California, Berkeley. In 1941 he was elected a Fellow of the American Physical Society. He was employed as a chemist by Eastman Kodak Research Laboratories.
Nando's has been established in Malaysia since 1998. The chain is very popular in the country and Malaysia is Nando's third largest market after the United Kingdom and Australia. Nando's is well known for its effective advertising that celebrates or satirises contemporary local issues. As of August 2021, Nando's has 73 restaurants operating throughout Malaysia (with the exception of Perlis and Labuan); 27 in Selangor, 19 in Kuala Lumpur, two in Putrajaya, five in Penang, four in Johor, three in Malacca, three in Perak, three in Sarawak, two in Negeri Sembilan and Sabah and one each in Kedah, Kelantan, Pahang, Terengganu. Nando's has been established in Pakistan since 2001. As of August 2021, Nando's has 12 restaurants throughout Pakistan; five in Karachi, four in Lahore and one each in Islamabad, Faisalabad and Rawalpindi. In Singapore, Nando's opened its first restaurant on 9 May 2010; and as of August 2021 there were six outlets throughout the city of Singapore.
==== Animal models ==== The safety of adjuvants are often tested using animal models. Model animals are given a dose of the adjuvant (sometimes comparable to real human/animal vaccines, sometimes higher) by injection, at a site that may or may not be analogous to real-life use. For example, aluminium adjuvants can kill motor neurons when subcutaneously injected at the scruff of a mouse's neck; oil–water suspensions such as pristane produces a precursor to lupus when given to mice by intraperitoneal injection; and arthritis-prone rat strains develop rheumatoid arthritis when injected with 0.2–0.3 mL squalene at the tail. All three examples above concern the classical "grandfathered" adjuvants: if a new adjuvant candidate shows these ill effects in animal testing, it would likely not be further developed, let alone becoming widely used. But more importantly, no effect similar to the above has been found in humans during the decades of their use (including among people genetically predisposed to autoimmunity), showing that animal models are not perfect models – nothing can be a perfect model of another thing, after all.
Sources: en.wikipedia.org
== Medical significance == Pathogenic mutations are the cause of a condition with symptoms including developmental disabilities, seizures, and problems with muscle coordination (ataxia), which is called NEDMAS (Neurodevelopmental disorder with microcephaly, ataxia, and seizures).
=== In electronics / electricity === PVDF is commonly used as insulation on electrical wires, because of its combination of flexibility, low weight, low thermal conductivity, high chemical corrosion resistance, and heat resistance. Most of the narrow 30-gauge wire used in wire wrap circuit assembly and printed circuit board rework is PVDF-insulated. In this use the wire is generally referred to as "Kynar wire", from the trade name. The piezoelectric properties of PVDF are exploited in the manufacture of tactile sensor arrays, inexpensive strain gauges, and lightweight audio transducers. Piezoelectric panels made of PVDF are used on the Venetia Burney Student Dust Counter, a scientific instrument of the New Horizons space probe that measures dust density in the outer Solar System. PVDF is the standard binder material used in the production of composite electrodes for lithium-ion batteries. Solution of PVDF 1−2% by mass in N-methyl-2-pyrrolidone (NMP) is mixed with an active lithium storage material such as graphite, silicon, tin, LiCoO2, LiMn2O4, or LiFePO4 and a conductive additive such as carbon black or carbon nanofibers. This slurry is cast onto a metallic current collector, and the NMP is evaporated to form a composite or paste electrode. PVDF is used because it is chemically inert over the potential range used and does not react with the electrolyte or lithium.
== S == S1 end mapping - S1 nuclease - satellite DNA - screening - SDS-PAGE - secondary structure - selection - selenium responsive proteins - sense strand - sequence - sequence motif - sequence polymorphism - sequence-tagged site - sequential epitope - severe combined immunodeficiency - sex chromosome - sex-linked - Shine-Dalgarno sequence - shotgun cloning - shotgun cloning or sequencing - shotgun sequencing - shuttle vector - Siah interacting protein N-terminal domain - sickle-cell disease - side chain - sigma factor - signal peptidase - signal sequence - silent mutation - single nucleotide polymorphism - siRNA - site-directed mutagenesis - site-specific recombination - Slc22a21 - slot blot - SNP - Slc22a21 - SMCR2 - snRNA - snRNP - solution hybridization - somatic cells - Southern blot - southwestern blot - SP6 RNA polymerase - SpAB protein domain - spectral karyotype - splicing - Simple Sequence Repeats (SSR) - SPR domain - SQ2397 - SRG1 RNA - ST7-AS2 - ST7-OT3 - stable transfection - start codon - stem-loop - sticky end - stomoxyn - stop codon - streptavidin - stringency - structural motif - sub-cloning - substitution - succinate—citramalate CoA-transferase - suicide gene - sulfate-transporting ATPase - suPARnostic - supercoil - SurE, survival protein E - Syb-prII-1 - syndrome -
=== Texas === Low-income minority women were more dependent on sterilization than other groups. In a study conducted in El Paso, Texas, groups of women were asked why they would choose sterilization; many of the top reasons included: not wanting any more children, their current age and health, plans of working or attending school or inability to afford another child.
=== Selection === The most common peptide aptamer selection system is the yeast two-hybrid system. Peptide aptamers can also be selected from combinatorial peptide libraries constructed by phage display and other surface display technologies such as mRNA display, ribosome display, bacterial display and yeast display. These experimental procedures are also known as biopanning. All the peptides panned from combinatorial peptide libraries have been stored in the MimoDB database.
Sources: en.wikipedia.org
It is a synthetic five-amino-acid peptide that acts as a growth hormone secretagogue. Three of its residues are non-standard amino acids, and the chain ends in an amide rather than a free acid. The molecule is small enough that it can be characterised by routine peptide analytical techniques.
It has not received marketing approval as a medicine in the United States or the European Union. Supplied material is generally described and handled as a research chemical. Regulatory treatment varies by jurisdiction, and some countries restrict growth hormone secretagogues under sports or medicines legislation.
Earlier secretagogues were associated with broader hormonal responses, including measurable changes in cortisol and prolactin. Reports on this peptide describe a narrower profile in which growth hormone release is the most prominent effect. The observation is influential because it shapes how the compound is compared with other members of the same receptor family.
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.