Everything below concerns GHS-R1a. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2026-06-14. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Material supplied for research use is normally a white to off-white lyophilized powder. The solid is hygroscopic and is handled in a low-humidity environment to limit water uptake. Bulk quantities are frequently shipped in sealed vials under inert gas. Once reconstituted in water or a neutral buffer, the solution is less stable than the dry powder and is usually divided into single-use aliquots.
Long-term storage of the dry powder is typically at minus twenty degrees Celsius or lower, protected from light and moisture. Solutions are commonly kept frozen and thawed only once, because repeated freeze-thaw cycles can promote aggregation and loss of measurable peptide content. Buffers near neutral pH are preferred over strongly acidic or strongly basic conditions. Shipping at ambient temperature is acceptable for short periods when the powder remains sealed and desiccated.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Pentapeptide with amidated C-terminus |
| Molecular weight | 711.85 g/mol | Monoisotopic mass |
| Primary receptor | GHS-R1a | Ghrelin receptor, Gq/11 coupled |
| Peptide class | Synthetic pentapeptide | Contains two non-natural residues |
| Reported selectivity | Lower cortisol and prolactin effect | Observed in animal and early human work |
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.
Common solvents for laboratory work include water, buffered saline, and dimethyl sulfoxide. Once dissolved, the peptide is exposed to hydrolysis and oxidation, and alkaline conditions accelerate breakdown. Low-binding plasticware and the addition of a carrier protein reduce losses to container surfaces, which can otherwise be substantial at low concentrations. Solutions are typically kept cold and used within days. Investigators working with the compound generally prepare fresh working dilutions rather than storing dilute stocks, and they avoid repeated warming of the same vial.
Reversed-phase high-performance liquid chromatography is the standard method for purity assessment, most often on a C18 column with a water and acetonitrile gradient and trifluoroacetic acid or formic acid as an ion-pairing agent. Mass spectrometry by electrospray or matrix-assisted laser desorption confirms the expected mass and reveals truncated or modified sequences. Amino acid analysis and sequencing provide orthogonal structural evidence. Typical impurities include deletion sequences, oxidized products, and dimeric species. Detection wavelength, usually 214 or 220 nanometers, should be reported because response factors differ between peptides.
Published animal and early human work describes growth hormone release that is separated from comparable rises in adrenocorticotropic hormone and cortisol. Prolactin changes are reported as small in the same studies. Selectivity is attributed to binding at the ghrelin receptor and to the downstream signaling that follows, rather than to differences in how quickly the peptide is cleared. Authors commonly label the compound selective rather than potent, because the same mass produces a smaller growth hormone response than some older secretagogues tested in parallel. Whether that profile holds across species and routes of administration remains an open question.
Human data remain limited and come mainly from small, short-term studies conducted decades ago. The peptide has not received approval as a medicine from major regulators, so current availability is largely as a research chemical. Reported effects on growth hormone pulsatility, appetite, and body composition should be read as preliminary, since few independent groups have replicated the original findings. Analytical characterization of research-grade material varies between suppliers, which complicates comparison across studies. Regulatory status also differs by country, and some jurisdictions classify it as a prescription-only or otherwise restricted item.
== Verwendung als industrieller Süßstoff == Brazzein eignet sich aufgrund seiner langanhaltenden und starken Süßkraft sowie der guten Verträglichkeit für Diabetiker als Zuckerersatz für die industrielle Massenproduktion von Nahrungsmitteln, wie auch die Proteine Thaumatin, Mabinlin, Miraculin, Monellin, Pentadin und Curculin. Es ist mit 50 mg/ml gut in Wasser löslich, und sowohl über einen weiten pH-Wertbereich als auch hitzebeständig, was wichtig für die industrielle Verarbeitung z. B. in Backwaren ist. Zudem ist sein Geschmack zuckerähnlicher als der der meisten anderen Süßungsmittel.
== Patentierungen == Obwohl die Früchte der Pentadiplandra brazzeana in Zentralafrika seit langem bekannt sind, wird Brazzein durch die Universität Wisconsin als deren eigene Erfindung beansprucht; Zusammenhänge mit den natürlichen Vorkommen in Gabun weist die Universität zurück. Die Universität hält drei Patente auf Verbindungen, die aus Pentadiplandra brazzeana isoliert werden, bzw. auf die industrielle Herstellung von Brazzein (US 5,326,580, US 5,346,998, US 5,527,555). Die Patentierung von Brazzein wird daher von GRAIN und Greenpeace als Biopiraterie eingestuft. Die zitierten Patente aus den 1990er Jahren sind aber bereits erloschen; Patente auf Basis der Naturstoffe – ohne die Nutzung genveränderter Organismen – sind daher nicht mehr möglich.
== Literatur == Walters, D.E. & Hellekant, G. (2006): Interactions of the sweet protein brazzein with the sweet taste receptor. In: J. Agric. Food. Chem. Bd. 54, S. 10129–10133. PMID 17177550 Zhao, Q. et al. (2005): Probing the sweet determinants of brazzein: wild-type brazzein and a tasteless variant, brazzein-ins(R18a-I18b), exhibit different pH-dependent NMR chemical shifts. In: Biochem. Biophys. Res. Commun. Bd. 335, 256–263. PMID 16105551 Assadi-Porter, F.M. et al. (2003): Correlation of the sweetness of variants of the protein brazzein with patterns of hydrogen bonds detected by NMR spectroscopy. In: J. Biol. Chem. Bd. 278, S. 31331–31339. PMID 12732626
Sources: de.wikipedia.org
== Eigenschaften == Bukatoxin ist ein Peptid und bindet an Natriumkanäle, wodurch diese dauerhaft geöffnet bleiben und Aktionspotentiale verlängert werden. Bukatoxin gehört zu den Skorpiontoxinen mit vier Disulfidbrücken und besitzt Cysteine an den Positionen 12, 16, 22, 26, 36, 46, 48 und 63. Vermutlich hemmt es die Inaktivierung von Natriumkanälen durch Bindung der Bindungsstelle 3.
Sources: de.wikipedia.org
It is a synthetic pentapeptide belonging to the growth hormone secretagogue family. Its principal characterized target is the ghrelin receptor, also called GHS-R1a. The molecule contains non-natural amino acids and an amidated C-terminus.
Both act at the same G protein-coupled receptor, but ipamorelin is a short synthetic peptide with modified residues rather than the natural 28-amino-acid hormone. Reports describe weaker effects on appetite and on cortisol or prolactin release than those seen with ghrelin. Its resistance to enzymatic breakdown also differs from that of the natural ligand.
Receptor binding and downstream calcium signaling are well characterized in cell-based systems. Effects measured in whole organisms are less consistent across studies and species. The extent to which selective receptor behavior drives the observed hormonal profile is still debated.
Dry powder is held at minus twenty degrees Celsius or colder, away from light and moisture. Sealed vials under inert gas limit degradation during storage.