The short version of Ipamorelin fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2026-01-25. Anything still debated is marked as such rather than presented as 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.
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.
| 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 |
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.
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.
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.
Twelve-tone technique alone is nothing but the principle of motivic elaboration and variation, as developed in the sonata, but elevated now to a comprehensive principle of construction, namely transformed into an a priori form and, by that token, detached from the surface of the composition. At this point Adorno reversed his earlier priorities: now his musical activities came second to the development of a philosophical theory of aesthetics. Thus, in the middle of 1929, he accepted Paul Tillich's offer to present a habilitation on Kierkegaard, which Adorno eventually submitted under the title The Construction of the Aesthetic. At the time, Kierkegaard's philosophy exerted a strong influence, chiefly through its claim to pose an alternative to Idealism and Hegel's philosophy of history. Yet when Adorno turned his attention to Kierkegaard, watchwords like "anxiety," "inwardness," and "leap"—instructive for existentialist philosophy—were detached from their theological origins and posed, instead, as problems for aesthetics. As the work proceeded—and Kierkegaard's overcoming of Hegel's idealism was revealed to be a mere interiorization—Adorno excitedly remarked in a letter to Berg that he was writing without looking over his shoulder at the faculty who would soon evaluate his work. Receiving favorable reports from Professors Tillich and Horkheimer, as well as Benjamin and Kracauer, the university conferred on Adorno the venia legendi in February 1931. On the very day his revised study was published, 23 March 1933, Hitler seized dictatorial powers.
=== MeSH D12.644.400 – neuropeptides === MeSH D12.644.400.070 – angiotensins MeSH D12.644.400.070.075 – angiotensin i MeSH D12.644.400.070.078 – angiotensin ii MeSH D12.644.400.070.080 – angiotensin iii MeSH D12.644.400.085 – bombesin MeSH D12.644.400.090 – bradykinin MeSH D12.644.400.095 – calcitonin MeSH D12.644.400.097 – calcitonin gene-related peptide MeSH D12.644.400.100 – carnosine MeSH D12.644.400.105 – cholecystokinin MeSH D12.644.400.120 – corticotropin MeSH D12.644.400.125 – corticotropin-releasing hormone MeSH D12.644.400.200 – delta sleep-inducing peptide MeSH D12.644.400.235 – fmrfamide MeSH D12.644.400.250 – galanin MeSH D12.644.400.275 – galanin-like peptide MeSH D12.644.400.300 – gastric inhibitory polypeptide MeSH D12.644.400.315 – gastrin-releasing peptide MeSH D12.644.400.320 – gastrins MeSH D12.644.400.340 – glucagon precursors MeSH D12.644.400.340.500 – glucagon MeSH D12.644.400.350 – gonadorelin MeSH D12.644.400.450 – motilin MeSH D12.644.400.460 – melanocyte-stimulating hormones MeSH D12.644.400.460.050 – alpha-msh MeSH D12.644.400.460.075 – beta-msh MeSH D12.644.400.460.115 – gamma-msh MeSH D12.644.400.465 – msh release-inhibiting hormone MeSH D12.644.400.470 – msh-releasing hormone MeSH D12.644.400.500 – neuropeptide y MeSH D12.644.400.525 – neurophysins MeSH D12.644.400.550 – neurotensin MeSH D12.644.400.575 – opioid peptides MeSH D12.644.400.575.180 – dynorphins MeSH D12.644.400.575.241 – endorphins MeSH D12.644.400.575.241.030 – alpha-endorphin MeSH D12.644.400.575.241.080 – beta-endorphin MeSH D12.644.400.575.241.360 – gamma-endorphin MeSH D12.644.400.575.281 – enkephalins MeSH D12.644.400.575.281.075 – enkephalin, ala(2)-mephe(4)-gly(5)- MeSH D12.644.400.575.281.231 – enkephalin, leucine MeSH D12.644.400.575.281.381 – enkephalin, methionine MeSH D12.644.400.575.281.600 – enkephalin, d-penicillamine (2,5)- MeSH D12.644.400.600 – pancreatic polypeptide MeSH D12.644.400.610 – peptide phi MeSH D12.644.400.625 – pituitary adenylate cyclase-activating polypeptide MeSH D12.644.400.640 – pituitary hormone release inhibiting hormones MeSH D12.644.400.645 – pituitary hormone-releasing hormones MeSH D12.644.400.680 – prolactin release-inhibiting hormone MeSH D12.644.400.700 – prolactin-releasing hormone MeSH D12.644.400.702 – thyrotropin-releasing hormone MeSH D12.644.400.705 – secretin MeSH D12.644.400.720 – somatostatin MeSH D12.644.400.740 – somatotropin-releasing hormone MeSH D12.644.400.800 – tachykinins MeSH D12.644.400.800.354 – eledoisin MeSH D12.644.400.800.475 – kassinin MeSH D12.644.400.800.500 – neurokinin a MeSH D12.644.400.800.550 – neurokinin b MeSH D12.644.400.800.625 – physalaemin MeSH D12.644.400.800.750 – substance p MeSH D12.644.400.875 – vasoactive intestinal peptide MeSH D12.644.400.900 – vasopressins MeSH D12.644.400.900.050 – argipressin MeSH D12.644.400.900.400 – lypressin MeSH D12.644.400.900.700 – oxytocin MeSH D12.644.400.900.900 – vasotocin
=== United States === The Orphan Drug Act (ODA) of January 1983, passed in the United States, with lobbying from the National Organization for Rare Disorders and many other organizations, is meant to encourage pharmaceutical companies to develop drugs for diseases that have a small market. Under the ODA drugs, vaccines, and diagnostic agents would qualify for orphan status if they were intended to treat a disease affecting fewer than 200,000 American citizens. Under the ODA orphan drug sponsors qualify for seven-year FDA-administered market Orphan Drug Exclusivity (ODE), "tax credits of up to 50% of R&D costs, R&D grants, waived FDA fees, protocol assistance and may get clinical trial tax incentives. In the U.S., orphan drug designation means that the sponsor qualifies for certain benefits, but it does not mean the drug is safe, effective or legal. In 2002, the Rare Diseases Act was signed into law. It amended the Public Health Service Act to establish the Office of Rare Diseases. It also increased funding for the development of treatments for people with rare diseases.
Sources: en.wikipedia.org
Cryopreservation for embryos is used for embryo storage, e.g., when IVF has resulted in more embryos than is currently needed. One pregnancy and resulting healthy birth has been reported from an embryo stored for 27 years, after the successful pregnancy of an embryo from the same batch three years earlier. Many studies have evaluated the children born from frozen embryos, or "frosties". The result has been uniformly positive with no increase in birth defects or development abnormalities. A study of more than 11,000 cryopreserved human embryos showed no significant effect of storage time on post-thaw survival for IVF or oocyte donation cycles, or for embryos frozen at the pronuclear or cleavage stages. Additionally, the duration of storage did not have any significant effect on clinical pregnancy, miscarriage, implantation, or live birth rate, whether from IVF or oocyte donation cycles. Rather, oocyte age, survival proportion, and number of transferred embryos are predictors of pregnancy outcome.
=== Pharmacodynamics === Most psychological effects can be accredited to the influx of serotonin caused by the psychoactive combination of DMT with beta-carbolines. Serotonin stimulates a group of G-protein coupled receptors known as 5-HT receptors. Specifically, stimulation of the 5-HT2A receptor type is correlated with hallucinogenic effects.
=== Effects in the brain === Luteinizing hormone receptors are located in areas of the brain associated with cognitive function. The role of LH role in the central nervous system (CNS) may be of relevance to understanding and treating post-menopausal cognitive decline. Some research has observed an inverse relationship between circulating LH and CNS LH levels. After ovariectomy (a procedure used to mimic menopause) in female mice, circulating LH levels surge while CNS levels of LH fall. Treatments that lower circulating LH restore LH levels in the CNS.
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.
It is a synthetic pentapeptide in the growth hormone secretagogue family. The chain contains five residues, two of which are non-natural amino acids.