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 2025-08-29. Numbers and descriptions here follow the published literature rather than marketing material.
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.
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 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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Value for the free base |
| Molar mass | 711.9 g/mol | Calculated from the formula |
| Appearance | White to off-white powder | Typical lyophilized form |
| Mechanism class | Ghrelin receptor agonist | Also described as a secretagogue |
| Half-life | About 2 hours | Reported for human circulation |
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。
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。
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 that acts on the growth hormone secretagogue receptor, also known as the ghrelin receptor. Its sequence contains five amino acid residues, including a non-natural residue that increases stability against enzymatic breakdown. The compound was developed in the 1990s as part of research into small peptides that stimulate pituitary hormone release. Unlike larger protein hormones, it can be produced by solid-phase peptide synthesis and characterized by standard analytical methods.
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.
Ipamorelin 是一种合成五肽，在 20 世纪 90 年代被报道为生长激素促分泌剂。其结构基于胃饥饿素受体激动剂的设计思路，但并非天然激素。早期药理学研究显示，它可刺激垂体释放生长激素，而对应激激素轴的影响相对较小。该化合物常被用作研究生长激素调节通路的工具分子。
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。
Pushpa Bhargava, founding director of the CSIR's Centre for Cellular and Molecular Biology in Hyderabad, endorsed the letter, calling Ayyadurai's sacking the worst of many cases he had seen of "vindictiveness in the CSIR" and accused CSIR administration of being "impervious to healthy and fair criticism". The incident was seen as an example of the difficulty some Indian expatriate professionals may encounter returning home after growing accustomed to the more direct management style of the U.S.
=== Cancer === Many human oncogenic viruses have been identified. For instance, HHV-8 is linked to Kaposi's sarcoma, the Epstein–Barr virus to Burkitt's lymphoma, and HPV to cervical cancer. In fact, the World Health Organization estimated (2002) that 17.8% of human cancers were caused by infection. The typical methods whereby viruses initiate oncogenesis involve suppressing the host's immune system, causing inflammation, or altering genes. HHV-6 has been detected in lymphomas, leukemias, cervical cancers, and brain tumors. Various medulloblastoma cell lines as well as the cells of other brain tumors have been demonstrated to express the CD46 receptor. Viral DNA has also been identified in many other non-pathological brain tissues, but the levels are lower. The human P53 protein functions as a tumor suppressor. Individuals who do not properly produce this protein experience a higher incidence of cancer, a phenomenon known as Li-Fraumeni syndrome. One of HHV-6's gene products, the U14 protein, binds P53 and incorporates it into virions. Another gene product, the ORF-1 protein, can also bind and inactivate P53. Cells expressing the ORF-1 gene have even been shown to produce fibrosarcomas when injected into mice. Another product of HHV-6, the immediate early protein U95, has been shown to bind nuclear factor-kappa B. Deregulation of this factor is associated with cancer.
==== Tubular aggregate myopathy ==== Although tubular aggregates are seen in a variety of myopathies, both genetic and environmental, the congenital myopathies associated with genes STIM1 and ORAI1 are known as tubular aggregate myopathy (TAM) types 1 and 2.
March 12: Law expanding the civil capacity of professional unions; married women may join and participate (including in administration and leadership) without their husband's permission. July 31: Law criminalizing incitement to abortion and anti-contraceptive propaganda. August 12: Decree enacting the Peace Treaty of November 27, 1919, which created the League of Nations (SDN) and established principles such as the prohibition of child labor, restrictions on youth labor for both sexes, and "equal pay for equal work"; women may be technical advisors within the SDN on certain topics. 1921
Square cut shoulder – shoulder roast, shoulder chops and arm chops Rack – rib chops and riblets, rib roast Loin – loin chops or roast Leg – sirloin chops, leg roast (leg of lamb) Neck Breast Shanks (fore or hind) Flank
Sources: en.wikipedia.org
ATSDR - Toxicity of Polycyclic Aromatic Hydrocarbons (PAHs) Archived 30 May 2020 at the Wayback Machine U.S. Department of Health and Human Services Fused Ring and Bridged Fused Ring Nomenclature Database of PAH structures Cagliari PAH Theoretical Database NASA Ames PAH IR Spectroscopic Database National Pollutant Inventory: Polycyclic Aromatic Hydrocarbon Fact Sheet Understanding Polycyclic Aromatic Hydrocarbons NASA Spitzer Space Telescope "The Aromatic World: An Interview with Professor Pascale Ehrenfreund" from Astrobiology Magazine Oregon State University Superfund Research Center focused on new technologies and emerging health risks of Polycyclic Aromatic Hydrocarbons (PAHs) Polycyclic Aromatic Hydrocarbons (PAHs)--EPA Fact Sheet. U.S. Environmental Protection Agency, Office of Solid Waste, January 2008.
==== September ==== On 1 September, the National Guard attacked the Walgha, Al-Majdal and Al-Mazraa fronts with a drone, then the Internal Security Forces clashed with the National Guard, leaving 10 members of the Internal Security Forces injured, conversely, the National Guard claimed that the Internal Security Forces launched mortar rounds and fired machine guns. On 4 September, groups considered as "outlaws" forced the expulsion of Atef Hneidi, known as "al-Basha", from the Suwayda governorate, this comes after Atef Hneidi issued a statement criticizing Hikmat al-Hijri. On 6 September, clashes broke out between the National Guard and the Syrian government forces, in the villages of Rima Hazem and Al-Mansoura, involving the use of heavy machine guns. On 10 September, Syrian state television reported that "criminal groups" blocked the al-Matouna checkpoint, meanwhile, a source in Suwayda claimed that Syrian internal security forces stationed in al-Matouna blocked the passage of tourists to Damascus without any explanation. On 24 September, Syrian government forces opened fire with machine guns on the city of Suwayda, and the National Guard responded to the attacks.
Rather than absolute concentrations of either two, it is the ratio of MMP and TIMP that maintains the proteolytic balance, and this ratio is found to be disturbed in diabetic ulcers. Despite these findings, the exact mechanism responsible for increased MMP activity in diabetes is not known yet. One possible line of thought considers Transforming growth factor beta (TGF-β) as an active player. Most MMP genes have TGF-β inhibitory element in their promoter regions and thus TGF–β regulates the expression of both MMP and their inhibitor TIMP. In addition to the importance of cell-cell and cell-matrix interactions, all phases of wound healing are controlled by a wide variety of different growth factors and cytokines. To mention precisely, growth factors promote switching of the early inflammatory phase to the granulation tissue formation. A decrease in growth factors responsible for tissue repair, such as TGF-β, is documented in diabetic wounds. Thus, reduced levels of TGFβ in diabetes cases lower the effect of inhibitory regulatory effect on MMP genes and thus cause MMPs to overexpress.
Bradykinin (BK) (from Greek brady- 'slow' + -kinin, kīn(eîn) 'to move') is a peptide that promotes inflammation. It causes arterioles to dilate (enlarge) via the release of prostacyclin, nitric oxide, and endothelium-derived hyperpolarizing factor, and induces smooth muscle constraction via prostaglandin F2. Bradykinin consists of nine amino acids, and is a physiologically and pharmacologically active peptide of the kinin group of proteins. A class of drugs called angiotensin-converting-enzyme inhibitors (ACE inhibitors) increase bradykinin levels by inhibiting its degradation, thereby increasing its blood pressure-lowering effect. ACE inhibitors are used to treat hypertension and heart failure.
Sources: en.wikipedia.org
It has not been approved as a therapeutic by major regulators, and the human trial record is small and dated. Material available today is mostly sold as a research chemical for laboratory use. Approval and restriction status varies by country.
It binds the ghrelin receptor, known as the growth hormone secretagogue receptor type 1a. Activation of that receptor triggers signaling that leads to growth hormone release. Selectivity for growth hormone over cortisol and prolactin is the property most often cited for this compound.
Published estimates place the circulating half-life at roughly two hours in humans. Clearance involves peptidase activity and renal handling. Because the peptide is short-lived, release patterns after administration are usually described as pulsatile rather than sustained.
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.