Everything below concerns GHSR-1a. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2026-02-10. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
Analytical confirmation relies on reversed-phase high-performance liquid chromatography, often coupled to mass spectrometry for identity and purity assessment. Mass spectrometry distinguishes the intact molecule from truncation products and from oxidation or deamidation variants that share similar chromatographic retention. Immunoassays appear in some biological studies but can cross-react with related peptides, so they are weaker tools for identity work. Reported purity figures depend heavily on the gradient, detector, and integration method used, which complicates direct comparison between laboratories.
Research quantities of ipamorelin are typically distributed as a white to off-white lyophilized powder. The solid dissolves readily in water and in aqueous buffers, and stock solutions are commonly prepared in sterile water or a mildly acidic diluent. Adsorption to plastic and glass surfaces can reduce the concentration of very dilute solutions, so containers and transfer steps deserve attention when accurate concentrations matter. Reconstituted material is generally used promptly rather than held for extended periods.
Storage recommendations for the dry solid center on low temperature and low moisture, most often -20 °C in a sealed, desiccated container protected from light. Solutions are less stable than the powder and are usually kept cold and used within a short window. Freeze-thaw cycling is a recognized source of loss, and aliquoting before freezing is a standard precaution. These practices derive from general peptide handling principles rather than from a single published stability trial, so exact shelf lives should be treated as approximate.
| 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 |
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.
Signal transduction begins when the peptide binds GHSR-1a on pituitary somatotrophs. The receptor couples to Gq/11 proteins, activating phospholipase C, which cleaves phosphatidylinositol bisphosphate into inositol trisphosphate and diacylglycerol. Inositol trisphosphate releases calcium from intracellular stores, and the resulting rise in cytosolic calcium drives growth hormone vesicle fusion. Concurrent Gs coupling and cyclic AMP elevation have also been reported, and the relative contribution of each arm to the overall secretory response is not fully settled.
Structural features distinguish the molecule from earlier secretagogues. An alpha-aminoisobutyric acid residue near the N-terminus and a D-naphthylalanine substitution increase receptor affinity, while C-terminal amidation improves resistance to exopeptidases. These modifications are associated with reduced stimulation of appetite and of the hypothalamic-pituitary-adrenal axis compared with hexarelin or growth hormone releasing peptide-6. Whether the same profile applies at every dose level studied is a matter of ongoing investigation rather than settled consensus.
Ipamorelin is a synthetic pentapeptide that acts as an agonist at the ghrelin receptor, also called the growth hormone secretagogue receptor type 1a. Its sequence incorporates non-natural residues, which slows enzymatic breakdown relative to short native peptides. In laboratory and early clinical work the compound is described as a selective growth hormone secretagogue because it raises growth hormone with comparatively little effect on other pituitary outputs. The degree to which that selectivity holds across species and dosing regimens remains an open question in the published literature.
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.
== Montignacs Theorie == Montignac geht davon aus, dass für die Gewichtszunahme vor allem die übermäßige Ausschüttung von Insulin entscheidend ist. Die dadurch bewirkte Hypoglykämie habe einen wesentlichen Anteil an der Fetteinlagerung, da sie für den Körper ein Signal von Nahrungsmangel ist, auf das dieser mit Fetteinlagerung reagiere. Ist dagegen der Insulin-Spiegel konstant niedrig, wird die aufgenommene Nahrung vollständig verbrannt – Fett kann abgebaut werden. Aus Montignacs Sicht besteht ein Problem der typischen Ernährungsgewohnheiten in den Industrieländern darin, dass viele Lebensmittel, da sie große Mengen von Zucker, vor allem Glukose und Saccharose enthalten, den Blutzuckerspiegel zu schnell und zu stark erhöhen. Das führe wiederum zu einer raschen Ausschüttung von Insulin. Außerdem würden im Laufe der landwirtschaftlichen Industrialisierung viele Lebensmittel wegen höherer Erträge und einfacheren Anbaus genetisch so verändert, dass sich ihr Ernährungswert verschlechterte. So erhöhten neben Zucker auch eine Reihe anderer Lebensmittel den Blutzuckerspiegel so stark und schnell (was wiederum zur raschen Ausschüttung von Insulin führe), dass man sie aus Sicht der Montignac-Methode zu den schlechten Kohlenhydraten zählt. Diese seien daher zu meiden:
Zucker Mais (der ursprüngliche indianische Mais wäre gut) Kartoffeln („verzüchtet“) geschälter Reis (Ausnahmen: Wildreis und Basmatireis) Weißmehl (und Folgeprodukte) gekochte Karotten (beim Kochen werden die guten Kohlenhydrate angeblich schlecht). Die langkettigen Kohlenhydratverbindungen der Karotten werden beim Kochen zu kurzkettigen Verbindungen (Glukose) aufgespalten, die den Blutzuckerspiegel höher ansteigen lassen als die ursprüngliche Verbindung. Bier (enthält Maltose, die noch schlechter als Zucker sei) Die Aufgabe der Bauchspeicheldrüse ist es, den Blutzuckerspiegel zu regulieren. Dazu produziert sie die Hormone Insulin und Glucagon. Bei einem starken Anstieg des Blutzuckerspiegels wird viel Insulin von der Bauchspeicheldrüse produziert, um den Blutzuckerspiegel wieder zu verringern. Die Aufnahme von schlechten Kohlenhydraten (siehe oben) und ein hoher Glykämischer Index führen laut Montignac zu einem Zustand der Hyperglykämie (hoher Blutzuckerwert), der in der Folge bei vielen Menschen zu einem Zustand der Hypoglykämie (Unterzucker) führe. Das sind Erkenntnisse aus der Diabetes-Forschung, die den GI überhaupt erst wissenschaftlich einführte. Nimmt man häufig und in großer Menge schlechte Kohlenhydrate zu sich, ist die Bauchspeicheldrüse stark beansprucht, weil sie häufig viel und schnell Insulin produzieren muss. Bei einigen Menschen gerät die Insulin-Ausschüttung außer Kontrolle und es wird selbst bei geringer Kohlenhydrat-Zufuhr übermäßig viel Insulin produziert (Hyperinsulinismus).
Bei funktionierendem Stoffwechsel werden auch hohe Blutzuckerwerte vom Körper reguliert. Durch die hohe Insulinausschüttung kommt es bei Diabetikern zu einer Insulinresistenz, d. h., sie reagieren nicht mehr richtig auf das Insulin und der Blutzuckerspiegel kann nicht abgesenkt werden. Das führt zu einer weiteren Verstärkung der Insulinausschüttung. Auf den Erkenntnissen aufbauend, dass Adipositas immer mit Hyperinsulinismus einhergeht und dass Insulin an der Einlagerung von Fett (Lipogenese) beteiligt ist, stellte Montignac die These auf, dass der Hyperinsulinismus die Ursache und nicht die Folge der Adipositas darstelle. Aus diesen Annahmen erklären sich die Grundregeln der Montignac-Methode:
Isst man überwiegend oder ausschließlich „sehr gute“ Kohlenhydrate, wird der Blutzuckerspiegel wenig erhöht und damit wenig Insulin produziert. Somit kann aufgenommenes Fett kaum als Speicherfett eingelagert werden. Bei „guten“ Kohlenhydraten, die Blutzucker- und Insulinspiegel erhöhen, darf man nur wenig Fett zu sich nehmen, denn das kann eingelagert werden. Bei „schlechten“ Kohlenhydraten kommt es zu einer starken Insulin-Produktion. So kann kein Fett abgebaut werden, sondern es wird neues Speicherfett eingelagert. Neben der angestrebten Gewichtsabnahme zielt die Methode vor allem darauf, eine „gestresste“ Bauchspeicheldrüse zur Ruhe kommen zu lassen. Montignac nimmt für sich in Anspruch, als erster Autor den GI als Basis für eine Ernährungsmethode genutzt zu haben. Montignac-Anhänger empfehlen, die schlechten Kohlenhydrate ganz wegzulassen. Dazu benötigt man allerdings Informationen zur Blutzucker steigernden Wirkung der einzelnen Bestandteile der täglichen Nahrung, die jeweils aus Tabellen entnommen werden müssen.
Sources: de.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.
Typical guidance is -20 °C in a sealed container with desiccant and protection from light. The powder tolerates handling better than a solution, but repeated warming and cooling is still avoided.