If you have been reading about 五肽 and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Updated 2026-01-04. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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.
Compared with older secretagogues such as hexarelin or GHRP-6, ipamorelin shows weaker stimulation of cortisol, prolactin, and appetite in the animal models used for early characterization. Whether that selectivity is preserved across longer human exposures remains an open question, because published clinical data are limited in size and duration. Reported effects on food intake are generally described as modest. The compound is therefore treated in the literature as a relatively selective research tool rather than a fully characterized therapeutic agent.
| 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 |
The molecule contains five residues, including alpha-aminoisobutyric acid, D-2-naphthylalanine, and D-phenylalanine, and it ends in a lysine amide. Non-natural and D-configured residues make the chain less susceptible to common peptidases, which helps explain its resistance to rapid breakdown. Its molecular formula is C38H49N9O5, corresponding to a free-base mass near 711.9 daltons. The C-terminal amide removes a negative charge and is a recurring feature in receptor-active peptides of this family. These structural choices are usually discussed as the basis for its selectivity profile.
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.
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.
Most published work on ipamorelin comes from rodent studies and small early-phase human trials. Subcutaneous and intravenous routes have been used, while oral delivery is limited by poor absorption and rapid breakdown in the gut. The reported plasma half-life is short, on the order of two hours, and varies with species and assay method. Whether chronic use produces meaningful clinical benefit remains unresolved, and long-term safety data in humans are sparse. No major regulatory agency has approved the compound as a therapeutic drug.
Ipamorelin 是一种合成五肽，序列为 Aib-His-D-2-Nal-D-Phe-Lys-NH2，分子式 C38H49N9O5，游离碱分子量约 711.85 g/mol。它属于生长激素促分泌素（GHS）家族，作用靶点是胃饥饿素受体 GHS-R1a。该化合物由诺和诺德的研究团队在二十世纪九十年代末报道，设计目标是提高对生长激素释放的选择性。C 端酰胺化与 N 端 Aib 残基是两个用于抵抗肽酶降解的结构特征。
在 GHS 家族中，早期肽类如 GHRP-6 与 GHRP-2 会同时促进生长激素、皮质醇与催乳素的释放，并明显增加食欲。Ipamorelin 在动物与早期人体研究中表现出对生长激素释放的相对选择性，对上述其他激素的影响较小。这种差异通常归因于受体结合模式与下游信号偏向的不同，而完整的分子解释仍有待补充。需要区分的是，选择性是研究观察中的相对程度，并非绝对界限。
从用途定位看，ipamorelin 目前主要以研究用肽的身份被讨论，未见主要药品监管机构将其批准为治疗药物。市售材料通常标注仅供研究使用，不得用于人体或诊断程序。文献中它常与生长激素促分泌素、GHS-R1a 激动剂、胃饥饿素拟似物等表述并列出现。既有研究的样本量普遍偏小，因此对其效应强度与一致性的描述应保持谨慎。
Allmusic's Brian Olewnick called it "Either/Orchestra's finest, most accomplished release" and said: "Beautifully recorded by legendary engineer Rudy van Gelder, the band is extraordinarily tight and vibrant, showing none of the muddy quality that would sully some of their later work ... Quite a journey, resulting in arguably the best of this unusual band's release. Very highly recommended".
==== Rise of organic chemistry and experimental physiology ==== In chemistry, one central issue was the distinction between organic and inorganic substances, especially in the context of organic transformations such as fermentation and putrefaction. Since Aristotle these had been considered essentially biological (vital) processes. However, Friedrich Wöhler, Justus Liebig and other pioneers of the rising field of organic chemistry—building on the work of Lavoisier—showed that the organic world could often be analyzed by physical and chemical methods. In 1828 Wöhler showed that the organic substance urea could be created by chemical means that do not involve life, providing a powerful challenge to vitalism. Cell extracts ("ferments") that could effect chemical transformations were discovered, beginning with diastase in 1833. By the end of the 19th century the concept of enzymes was well established, though equations of chemical kinetics would not be applied to enzymatic reactions until the early 20th century. Physiologists such as Claude Bernard explored (through vivisection and other experimental methods) the chemical and physical functions of living bodies to an unprecedented degree, laying the groundwork for endocrinology (a field that developed quickly after the discovery of the first hormone, secretin, in 1902), biomechanics, and the study of nutrition and digestion. The importance and diversity of experimental physiology methods, within both medicine and biology, grew dramatically over the second half of the 19th century.
=== Holland Sweetener Company === A joint venture of DSM and Tosoh, the Holland Sweetener Company manufactured aspartame using the enzymatic process developed by Toyo Soda (Tosoh) and sold as the brand Sanecta. Additionally, they developed a combination aspartame-acesulfame salt under the brand name Twinsweet. They left the sweetener industry in 2006, because "global aspartame markets are facing structural oversupply, which has caused worldwide strong price erosion over the last five years", making the business "persistently unprofitable".
Sources: en.wikipedia.org
== See also == Androgenic hair Bearded lady Ferriman-Gallwey score Hair removal Hypertrichosis Laser hair removal Petrus Gonsalvus Polyendocrine metabolic ovarian syndrome (PMOS) Pubic hair Social model of disability Trichophilia
Hylomorphism is a philosophical doctrine developed by the Ancient Greek philosopher Aristotle, which conceives every physical entity or being (ousia) as a compound of matter (potency) and substantial form (act), with the generic form as immanently real within the individual. The word is a 19th-century term formed from the Greek words ὕλη (hyle: "wood, matter") and μορφή (morphē: "form"). Hylomorphic theories of physical entities have been undergoing a revival in contemporary philosophy, especially since the 2000s.
=== Food sources === Hydra, as a carnivorous cnidarian, mainly feeds on small aquatic invertebrates. Hydra can also eat worms, young insects, larval mollusks, bluegill larvae, tiny crustaceans (e.g., Daphnia, Cyclops, ostracods, cladocerans, and copepods), and algaes (e.g., Cocconeis placentula, Cyclotella meneghineana, and Navicula zanoni). Some species of Hydra exist in a mutual relationship with various types of unicellular algae. The algae are protected from predators by Hydra; in return, photosynthetic products from the algae are beneficial as a food source to Hydra and even help to maintain the Hydra microbiome. There is an entire clade of "green hydra" where the species can stably maintain a population of Chlorella internally, with the main representative being Hydra viridissima. There are at least 4 species in this clade. The other species are called "brown hydra". There exists an immature symbiotic relationship between some strains of Hydra vulgaris and Chlorococcum.
==== Antibody-drug conjugates ==== Antibody-drug conjugates (ADCs) comprise an antibody, drug and a linker between them. The antibody will be targeted at a preferentially expressed protein in the tumour cells (known as a tumor antigen) or on cells that the tumor can utilise, such as blood vessel endothelial cells. They bind to the tumor antigen and are internalised, where the linker releases the drug into the cell. These specially targeted delivery vehicles vary in their stability, selectivity, and choice of target, but, in essence, they all aim to increase the maximum effective dose that can be delivered to the tumor cells. Reduced systemic toxicity means that they can also be used in people who are sicker and that they can carry new chemotherapeutic agents that would have been far too toxic to deliver via traditional systemic approaches. The first approved drug of this type was gemtuzumab ozogamicin (Mylotarg), released by Wyeth (now Pfizer). The drug was approved to treat acute myeloid leukemia. Two other drugs, trastuzumab emtansine and brentuximab vedotin, are both in late clinical trials, and the latter has been granted accelerated approval for the treatment of refractory Hodgkin's lymphoma and systemic anaplastic large cell lymphoma.
Sources: en.wikipedia.org
Codeine/paracetamol, also called codeine/acetaminophen and co-codamol, is a compound analgesic, comprising codeine phosphate and paracetamol (acetaminophen). Codeine/paracetamol is used for the relief of mild to moderate pain when paracetamol or non-steroidal anti-inflammatory drugs (NSAIDs; such as ibuprofen, aspirin, and naproxen) alone do not sufficiently relieve symptoms. In 2023, it was the 210th most commonly prescribed medication in the United States, with more than 2 million prescriptions.
The 2023 Nobel Prize in Physiology or Medicine was awarded to Katalin Karikó and Drew Weissman for the development of effective mRNA vaccines against COVID-19. New approaches to modulate RNA levels as a therapeutics include the use of antisense oligonucleotides, including for neurodevelopment diseases associated with high mortality.
=== Early years of PGCPS (1899–1974) === In 1899, Laurel High was founded as the first high school in Prince George's County. Situated at Montgomery and Eighth Streets in Downtown Laurel, it began with nine teachers and 59 students, with the 1900 graduating class being all women. The school's roof served as a Civil Defense aircraft spotting station during World War II. By 1965, the school relocated to a more expansive campus. The original building, listed on the National Register of Historic Places in 1979, now functions as a community center. In 1952, the school district permitted black students to attend grades 1–12. Before this, black students in the county were limited to the 11th grade, while only white students could progress to the 12th grade. PGCPS ran three high schools exclusively for black students before desegregation: Marlboro Colored High (now Frederick Douglass High School) in Upper Marlboro, Lakeland High School in College Park and Fairmont Heights High School.
Sources: en.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.
It is a synthetic pentapeptide in the growth hormone secretagogue family. The chain contains five residues, two of which are non-natural amino acids.