This is a working overview of pentapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-09-03. 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.
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。
| 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 |
At the receptor level, ipamorelin binds GHS-R1a and triggers signaling through Gq-coupled pathways. Activation leads to calcium release and downstream effects in pituitary somatotroph cells. These events promote the release of growth hormone into circulation. The response depends on the presence of the receptor and on the physiological state of the animal or tissue studied. Because the receptor is also found in other tissues, effects beyond the pituitary have been examined in laboratory models, though the extent of those effects remains an area of ongoing study.
One distinguishing feature reported in animal studies is selectivity. Ipamorelin stimulated growth hormone release with limited elevation of adrenocorticotropic hormone or cortisol compared with earlier secretagogues such as GHRP-6. This pattern has been described as more selective for the growth hormone axis. The finding comes mainly from preclinical work, and the degree to which it holds across species and doses is not fully settled. Reports also describe effects on gastric motility in animal models, suggesting activity outside the pituitary, though the clinical relevance of this observation is uncertain.
Ipamorelin is a synthetic pentapeptide classified as a growth hormone secretagogue. Its sequence, Aib-His-D-2-Nal-D-Phe-Lys-NH2, combines three non-proteinogenic residues with a C-terminal amide. The N-terminal aminoisobutyric acid unit and the two aromatic D-amino acids distinguish it from peptides assembled only from standard L-amino acids. Its formula is C38H49N9O5, corresponding to an average mass near 711.9 Da. At neutral pH the molecule carries a net positive charge, a property that shapes its behaviour in chromatographic and electrophoretic systems.
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.
As numerous ASSRs declared sovereignty and self-promotion to Soviet Socialist Republics, Art. 71 and 72 of the Constitution of the RSFSR were amended on May 24, 1991 to recognize its autonomous republics as SSRs; it was further amended on July 3 to promote all its autonomous oblasts other than Jewish Autonomous Oblast to SSRs. This decision came into conflict with Art. 85 of the Constitution of the USSR.
=== Compressibility === The compressibility of a salt is strongly determined by its structure, and in particular the coordination number. For example, halides with the caesium chloride structure (coordination number 8) are less compressible than those with the sodium chloride structure (coordination number 6), and less again than those with a coordination number of 4.
=== International perspective === Rhodesia's Unilateral Declaration of Independence from the United Kingdom on 11 November 1965 was promptly condemned by the international community. The United Nations Security Council Resolution 216 of 12 November 1965 called "upon all States not to recognise this illegal racist minority regime in Southern Rhodesia." Rhodesia campaigned for international acceptance and invoked the doctrine of non-intervention in internal affairs as justification for rebuking external criticism of its internal policies. However, the emerging doctrine of self-determination in colonial situations meant that most nations regarded Rhodesia's self-declared independence as illegitimate. Zambia, formerly Northern Rhodesia, took a pragmatic approach towards Rhodesia. Kenneth Kaunda, heavily dependent on access through Rhodesia for his nation's copper ore exports, fuel, and power imports unofficially worked with the Rhodesian government. Rhodesia still allowed Zambia to export and import its goods through its territory to Mozambique ports, despite the Zambian government's official policy of hostility and non-recognition of the post-UDI Smith Administration. The United States, like all other Western nations, refused to recognise Rhodesia, but unlike others allowed its Consulate-General to function as a communications conduit between the US government in Washington, DC and the Rhodesian government in Salisbury. When Rhodesia set up the Rhodesian Information Office in Washington, DC, OAS nations loudly protested.
Sources: en.wikipedia.org
The large POMC precursor is the source of numerous biologically active peptides, which are produced through sequential enzymatic cleavage. These include: N-Terminal Peptide of Proopiomelanocortin (NPP, or pro-γ-MSH) α-Melanotropin (α-Melanocyte-Stimulating Hormone, or α-MSH) β-Melanotropin (β-MSH) γ-Melanotropin (γ-MSH) 𝛿-Melanocyte-Stimulating Hormone (𝛿-MSH), found in sharks ε-Melanocyte-Stimulating Hormone (ε-MSH), present in some teleost fish Corticotropin (Adrenocorticotropic Hormone, or ACTH) Corticotropin-like Intermediate Peptide (CLIP) β-Lipotropin (β-LPH) Gamma Lipotropin (γ-LPH) β-Endorphin [Met]Enkephalin Although the first five amino acids of β-Endorphin are identical to [Met]enkephalin, β-Endorphin is not generally believed to be a precursor of [Met]enkephalin. Instead, [Met]enkephalin is produced independently from its own precursor, proenkephalin A. The production of β-MSH occurs in humans, but not in mice or rats, due to the absence of the necessary cleavage site in the rodent POMC sequence.
Metandienone, also known as methandienone or methandrostenolone and sold under the brand name Dianabol (D-Bol) among others, is an androgen and anabolic steroid (AAS) medication which is mostly no longer prescribed. It is also used non-medically for physique- and performance-enhancing purposes. It is often taken by mouth. Side effects of metandienone include symptoms of masculinization like acne, increased hair growth, voice changes, and increased sexual desire, estrogenic effects like fluid retention and breast enlargement, and liver damage. The drug is an agonist of the androgen receptor (AR), the biological target of androgens like testosterone and dihydrotestosterone (DHT), and has strong anabolic effects and moderate androgenic effects. It also has moderate estrogenic effects. Metandienone was originally developed in 1955 by CIBA and marketed in Germany and the United States. As the CIBA product Dianabol, metandienone quickly became the first widely used AAS among professional and amateur athletes, and remains the most common orally active AAS for non-medical use. It is currently a controlled substance in the United States and United Kingdom and remains popular among bodybuilders. Metandienone is readily available without a prescription in certain countries such as Mexico, and is also manufactured in some Asian countries.
=== Hart House === In August 2022, Hart debuted a vegan restaurant, Hart House, to compete with fast-food chains by "offering flavorful plant-based alternatives". The restaurant opened in Los Angeles, California, about a mile from Los Angeles International Airport (LAX), with a simple menu of veggie burgers and Chick'n products. The restaurant's offerings are claimed to be "entirely free of cholesterol, antibiotics, hormones, artificial colors, preservatives, high-fructose corn syrup, or trans fats", and inspired by Hart's own "health nut" lifestyle. Hart opened a second location in Monrovia, California, in November 2022, a third on Sunset Boulevard in Hollywood, California, in May 2023, and a fourth location near the University of Southern California campus in June 2023. All locations closed in September 2024.
== Calcination equilibrium == Calcination of limestone using charcoal fires to produce quicklime has been practiced since antiquity by cultures all over the world. The temperature at which limestone yields calcium oxide is usually given as 825 °C, but stating an absolute threshold is misleading. Calcium carbonate exists in equilibrium with calcium oxide and carbon dioxide at any temperature. At each temperature there is a partial pressure of carbon dioxide that is in equilibrium with calcium carbonate. At room temperature the equilibrium overwhelmingly favors calcium carbonate, because the equilibrium CO2 pressure is only a tiny fraction of the partial CO2 pressure in air, which is about 0.035 kPa. At temperatures above 550 °C the equilibrium CO2 pressure begins to exceed the CO2 pressure in air. So above 550 °C, calcium carbonate begins to outgas CO2 into air. However, in a charcoal fired kiln, the concentration of CO2 will be much higher than it is in air. Indeed, if all the oxygen in the kiln is consumed in the fire, then the partial pressure of CO2 in the kiln can be as high as 20 kPa.
Sources: en.wikipedia.org
In June 1997, Zhang Hongchao was studying at Henan University of Economics and Law when he opened a shaved‑ice stall in Zhengzhou using a CN¥3,000 loan from his grandmother. The stall's early success convinced him to expand, and in 1999 he opened a second stand called Mixue Bingcheng. Due to a lack of experience, Hongchao had closed three stores in a little more than a year. Following the closure of his third store, he went to Hefei to sell tanghulu, which also failed. In spring 1999, Hongchao returned to Zhengzhou to start a new cold drink shop, though this would also be demolished; the failures of these street stalls were attributed to poor locations and ongoing urbanization.
Opportunism is also a key factor – the organized criminal or criminal group is likely to frequently reorder the criminal associations they maintain, the types of crimes they perpetrate, and how they function in the public arena (recruitment, reputation, etc.) in order to ensure efficiency, capitalization and protection of their interests.
=== Sprouting angiogenesis === Sprouting angiogenesis was the first identified form of angiogenesis and because of this, it is much more understood than intussusceptive angiogenesis. It occurs in several well-characterized stages. The initial signal comes from tissue areas that are devoid of vasculature. The hypoxia that is noted in these areas causes the tissues to demand the presence of nutrients and oxygen that will allow the tissue to carry out metabolic activities. Because of this, parenchymal cells will secrete vascular endothelial growth factor (VEGF-A) which is a proangiogenic growth factor. These biological signals activate receptors on endothelial cells present in pre-existing blood vessels. Second, the activated endothelial cells, also known as tip cells, begin to release enzymes called proteases that degrade the basement membrane to allow endothelial cells to escape from the original (parent) vessel walls. The endothelial cells then proliferate into the surrounding matrix and form solid sprouts connecting neighboring vessels. The cells that are proliferating are located behind the tip cells and are known as stalk cells. The proliferation of these cells allows the capillary sprout to grow in length simultaneously. As sprouts extend toward the source of the angiogenic stimulus, endothelial cells migrate in tandem, using adhesion molecules called integrins. These sprouts then form loops to become a full-fledged vessel lumen as cells migrate to the site of angiogenesis.
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.
两者都是 GHS-R1a 激动剂，但 ipamorelin 在研究中显示出更高的生长激素释放选择性。早期资料显示它对皮质醇、催乳素与食欲的刺激弱于 GHRP-6。这些差异是相对程度，而非绝对区分。