A practical reference on growth hormone secretagogue: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-09-08. Anything still debated is marked as such rather than presented as settled.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Reported for the free peptide |
| Molecular mass | 711.85 Da | Monoisotopic value |
| Residue motif | Aib-His-D-2-Nal-D-Phe-Lys-NH2 | Non-natural residues at positions one and three |
| Primary target | GHSR-1a | Ghrelin receptor, G protein coupled |
| Reported plasma half-life | About two hours | Values vary with assay and subject group |
在机制层面，ipamorelin 与生长激素促分泌受体 1a 型结合，该受体也介导胃饥饿素的多种效应。受体激活后，细胞内信号促进生长激素从垂体前叶释放。由于对促肾上腺皮质激素和皮质醇的刺激较弱，它被视为选择性较高的促分泌剂。这种选择性在动物模型和少量人体研究中被观察到，但人体数据仍然有限。
现有文献多来自小规模、短期的研究，涉及生长激素缺乏、术后肠麻痹等方向。长期使用是否导致受体脱敏，以及重复给药后效应是否衰减，仍属开放问题。不同研究之间的剂量、给药途径和受试者特征差异较大，因此结论外推需谨慎。关于临床获益的确切证据尚不充分，需要更大规模的对照试验来澄清。
Compared with other secretagogues such as GHRP-2, GHRP-6, and hexarelin, ipamorelin is described as more selective. Published animal work reports little or no increase in adrenocorticotropic hormone, cortisol, or prolactin at doses that release growth hormone. This selectivity is the property most often cited in the research literature. Whether the same profile holds across species and dosing schedules remains an open question, since human data are limited and come largely from small studies.
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, and its molecular mass is approximately 711.9 daltons. The compound was described in the late 1990s by researchers seeking molecules that release growth hormone with fewer side effects than earlier secretagogues. It is a laboratory and research compound, not an approved medicine in most jurisdictions.
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.
Main dishes are usually centred on a sauce or stew of simsim, groundnuts, beans or meat. The starch traditionally comes from posho (maize meal) or matooke (steamed and mashed green banana) in the central or kalo (an ugali dish made from millet) in the north, east and west. Posho or millet is cooked as a porridge for breakfast. For main meals, white maize flour is added to the saucepan and stirred into the posho until the consistency is firm. It is then turned out onto a serving plate and cut into individual slices (or served onto individual plates in the kitchen). Cassava, yam, and African sweet potato are also eaten; the more affluent include white (often called "Irish" or "Western"/mazungu) potato and rice in their diets. Soybeans were promoted as a healthy food staple in the 1970s and this is also occasionally eaten for breakfast, although mostly used as feed for animals. Chapati, similar to Asian flatbreads, are also part of Ugandan cuisine.
== See also == Allicin, the active piquant flavor chemical in uncooked garlic, and to a lesser extent onions (see those articles for discussion of other chemicals in them relating to pungency, and eye irritation) Capsazepine, capsaicin antagonist Iodoresiniferatoxin, an ultrapotent capsaicin antagonist derived from Resiniferatoxin Naga Viper pepper, Bhut Jolokia Pepper, Carolina Reaper, Trinidad Moruga Scorpion; some of the world's most capsaicin-rich fruits Piperine, the active flavor chemical in black pepper List of capsaicinoids
Alzheimer's disease: A study published in Archives of Neurology in February 2003 suggested that the intake of both trans fats and saturated fats promote the development of Alzheimer disease, although not confirmed in an animal model. It has been found that trans fats impaired memory and learning in middle-age rats. The trans-fat eating rats' brains had fewer proteins critical to healthy neurological function and inflammation in and around the hippocampus, the part of the brain responsible for learning and memory. These are the exact types of changes normally seen at the onset of Alzheimer's, but seen after six weeks, even though the rats were still young. A systematic review of five articles based on four prospective cohort studies of individuals did not find a robust association between their intake of trans fatty acids and development of Alzheimer's disease (or several other forms of dementia). The review based this conclusion on finding that 4 of the 5 reports appeared biased and therefore recommended more well-designed prospective studies to clarify this issue. Cancer: In 2007 the American Cancer Society stated that a relationship between trans fats and cancer "has not been determined." One study has found a positive connection between trans fat and prostate cancer. However, a larger study found a correlation between trans fats and a significant decrease in high-grade prostate cancer.
== Mechanism == Aspartate transaminase, as with all transaminases, operates via dual substrate recognition; that is, it is able to recognize and selectively bind two amino acids (Asp and Glu) with different side-chains. In either case, the transaminase reaction consists of two similar half-reactions that constitute what is referred to as a ping-pong mechanism. In the first half-reaction, amino acid 1 (e.g., L-Asp) reacts with the enzyme-PLP complex to generate ketoacid 1 (oxaloacetate) and the modified enzyme-PMP. In the second half-reaction, ketoacid 2 (α-ketoglutarate) reacts with enzyme-PMP to produce amino acid 2 (L-Glu), regenerating the original enzyme-PLP in the process. Formation of a racemic product (D-Glu) is very rare. The specific steps for the half-reaction of enzyme-PLP + aspartate
is the acceleration due to gravity. Thus, among completely submerged objects with equal masses, objects with greater volume have greater buoyancy. Suppose a rock's weight is measured as 10 newtons when suspended by a string in a vacuum with gravity acting on it. Suppose that, when the rock is lowered into the water, it displaces water of weight 3 newtons. The force it then exerts on the string from which it hangs would be 10 newtons minus the 3 newtons of buoyant force: 10 − 3 = 7 newtons. Buoyancy reduces the apparent weight of an object. It is generally easier to lift an object through the water than it is to pull it out of the water. For a fully submerged object, Archimedes' principle can be reformulated as follows:
Sources: en.wikipedia.org
On 28 September 2010, former captain James Hird was named as Essendon's new coach from 2011 on a four-year deal. Former Geelong dual premiership-winning coach and Essendon triple-premiership winning player Mark Thompson later joined the coaching panel. Thompson introduced Essendon to performance coach Dean Robinson, with whom he had worked at Geelong; and, at Robinson's suggestion, they were introduced to sports scientist Stephen Dank. The club believed that it was lagging the rest of the competition in its supplements, particularly to aid player recovery. Subsequently, the club hired Robinson as high-performance coach in September 2011 and hired Dank as a sports scientist in November 2011. Dank was given primary responsibility to establish and run the supplements program. The program primarily comprised subcutaneous injections of supplements to improve soft tissue recovery times, to enable players to endure and benefit from a heavier training workload. The players signed consent forms for the program and were assured that all substances were ASADA-approved. The program included injections of AOD-9604, colostrum, Tribulus and an unspecified variety of thymosin supplement which was described on forms only as "thymosin" – which the Court of Arbitration for Sport (CAS) would later conclude was the banned, performance-enhancing thymosin beta-4 variety. The program also included supplements in pill form and intravenous vitamin drips.
USDA RDA chart in PDF format Archived 9 November 2021 at the Wayback Machine Health Canada Dietary Reference Intakes Reference Chart for Vitamins NIH Office of Dietary Supplements: Fact Sheets Archived 16 September 2008 at the Wayback Machine "Vitamins and minerals". nhs.uk. 23 October 2017.
== History == Epidemics of meningococcal A meningitis, which is a bacterial infection of the thin lining surrounding the brain and spinal cord, have swept across 26 countries in sub-Saharan Africa for a century, killing and disabling young people every year. The disease is highly feared on the continent; it can kill or cause severe brain damage in a child within hours. Epidemics usually start at the beginning of the calendar year when dry sands from the Sahara Desert begin blowing southward. The largest meningitis epidemic in African history swept across sub-Saharan Africa from 1996 to 1997, numbering 250,000 new cases and taking 25,000 lives. Three years later, the World Health Organization (WHO) held a technical consultation in Cairo, Egypt with African ministers of health and global health leaders to discuss meningitis and the development of a new vaccine. At that meeting, representatives from eight African countries issued a statement saying that the development of a meningococcal vaccine to prevent epidemics was a high priority for them, and concluded that a conjugate meningococcal vaccine would have the potential to prevent future epidemics. They estimated that the new vaccine could become available in three to seven years for US$0.40 to $1 a dose, providing protection for at least ten years. A year later, in 2001, the Bill & Melinda Gates Foundation provided a ten-year, $70 million grant to establish the Meningitis Vaccine Project, a partnership between PATH and WHO.
Three of the four outer-shell electrons of each atom in a graphene sheet occupy three sp2 hybrid orbitals – a combination of orbitals s, px and py — that are shared with the three nearest atoms, forming σ-bonds. The length of these bonds is about 0.142 nanometers. The remaining outer-shell electron occupies a pz orbital that is oriented perpendicularly to the plane. These orbitals hybridize together to form two half-filled bands of free-moving electrons, π, and π∗, which are responsible for most of graphene's notable electronic properties. Recent quantitative estimates of aromatic stabilization and limiting size derived from the enthalpies of hydrogenation (ΔHhydro) agree well with the literature reports. Graphene sheets stack to form graphite with an interplanar spacing of 0.335 nm (3.35 Å). Graphene sheets in solid form usually show evidence in diffraction for graphite's (002) layering. This is true of some single-walled nanostructures. However, unlayered graphene displaying only (hk0) rings have been observed in the core of presolar graphite onions. TEM studies show faceting at defects in flat graphene sheets and suggest a role for two-dimensional crystallization from a melt.
Sources: en.wikipedia.org
Both molecules activate the same receptor, GHSR-1a, but they share little sequence identity. Ghrelin is a 28-amino-acid hormone carrying a distinctive acyl modification, whereas ipamorelin is a short synthetic peptide. The shared target explains overlapping endocrine effects, while the different structures account for differences in metabolic stability and receptor selectivity.
Early animal and human studies reported growth hormone release at levels that produced small changes in cortisol, prolactin and adrenocorticotropic hormone. That contrast with older secretagogues gave rise to the selectivity label. The observation is consistent across several reports but rests on a limited number of small studies.
Plasma peptidases cleave the molecule into smaller fragments, and reported half-lives in human studies are on the order of a couple of hours. The identity and activity of individual breakdown products have not been fully mapped. Questions about tissue-level clearance remain open.
Reversed-phase liquid chromatography is standard for purity, and mass spectrometry is standard for identity. Amino acid analysis is used when quantitative composition matters. No single technique answers every question, so laboratories usually combine two or three.