growth hormone secretagogue is one of those subjects where the details matter more than the headlines. This page pulls together the background, the mechanisms, and the practical points readers ask about most.
Updated 2026-01-06. Numbers and descriptions here follow the published literature rather than marketing material.
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 class. It acts as an agonist at the ghrelin receptor, also called the growth hormone secretagogue receptor type 1a. The compound was designed in the 1990s during a search for agents that release growth hormone with fewer off-target hormonal effects than earlier secretagogues. It appears in the research literature under several sequence-based names. Material supplied for laboratory work is normally a lyophilized solid, and it is not marketed as an approved therapeutic in major jurisdictions.
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.
In animal and early human studies, ipamorelin produces pulsatile growth hormone release and a secondary rise in insulin-like growth factor 1. The magnitude and duration of that rise depend on route, sampling schedule, and the baseline endocrine state of the subject. Whether repeated exposure alters the response over time is not firmly settled, since some reports describe stable pulsatility while others note attenuation. Most published data come from small samples, which limits the strength of any general claim about long-term behavior.
Ipamorelin is a synthetic pentapeptide that belongs to the growth hormone secretagogue class of compounds. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, a structure that differs from natural ghrelin in length and in the presence of non-natural amino acid residues. Early laboratory work described it as a comparatively selective agent that stimulates growth hormone release with limited effect on other pituitary hormones. The compound is supplied as a lyophilized solid for research use and has no identified natural source in the body.
| 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 |
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.
At the molecular level, ipamorelin acts as an agonist at the growth hormone secretagogue receptor, also called the ghrelin receptor or GHS-R1a. Binding to this receptor on pituitary somatotroph cells triggers a signaling cascade that leads to growth hormone release. The effect is mediated through phospholipase C and calcium mobilization rather than through the cyclic AMP pathway used by growth hormone releasing hormone. The two pathways are complementary, and combined stimulation produces a larger response than either alone.
冻干状态下的肽通常比溶液状态更稳定，常规做法是维持 -20 °C 或更低温度、保持干燥并避开强光。复溶后的降解主要来自水解、氧化与脱酰胺，速率受 pH、缓冲液种类、离子强度与温度共同影响，碱性条件一般会加快这些反应。反复冻融会造成聚集与容器吸附损失，分装保存能降低该风险。容器材质与金属离子也可能参与氧化过程，需与操作条件一并考虑。
对 ipamorelin 的常规表征以反相高效液相色谱测定纯度，检测波长多设为 214 nm，因为肽键在该波长有较强吸收。身份确认通常借助电喷雾电离质谱或串联质谱，将实测分子量与理论值逐项比对。序列层面可用肽图分析或氨基酸分析进一步验证。这些手段组合起来，可以分别覆盖纯度、身份与序列三个不同层次的信息。
杂质谱一般包含缺失序列片段、差向异构体、氧化产物以及残留溶剂或反离子，其中组氨酸与芳香残基的氧化常被重点关注。反相色谱中这类杂质往往紧邻主峰洗脱，因此方法需要足够的分离度并经过系统适用性验证。纯度百分比的解读依赖于检测波长与梯度条件，不同实验室公布的数字不宜直接横向比较。参考标准品有助于跨批次对照，但其自身赋值同样需要可追溯来源。
=== Properties === Banting House, his former home located in London, Ontario, was declared a National Historic Site of Canada in 1997. The house contains a museum of the history of insulin, as well as Banting's artwork. The Banting Interpretation Centre in Musgrave Harbour, Newfoundland and Labrador is a museum named after him which focuses on the circumstances surrounding the 1941 plane crash which claimed his life. The crater Banting on the Moon is also named after him for his contributions to medicine. During the voting for "Greatest Canadians" in late 2003, controversy rose over the future use of the Banting family farm in New Tecumseth which had been left to the Ontario Historical Society by Banting's late nephew, Edward, in 1998. The dispute centred on the future use of the 40 ha (99 acres) property and its buildings. In a year-long negotiation, assisted by a provincially appointed facilitator, the Town of New Tecumseth offered $1 million to the Ontario Historical Society (OHS). The town intended to turn the property over to the Sir Frederick Banting Legacy Foundation for preservation of the property and buildings, and the Legacy Foundation planned to erect a Camp for Diabetic Youths. The day after the November 22, 2006, deadline for the OHS to sign the agreement, the OHS announced that it had sold the property for housing development to Solmar Development for more than $2 million. The Town of New Tecumseth announced it would designate the property under the Ontario Heritage Act.
Actin was first observed experimentally in 1887 by W.D. Halliburton, who extracted a protein from muscle that 'coagulated' preparations of myosin that he called "myosin-ferment". However, Halliburton was unable to further refine his findings, and the discovery of actin is credited instead to Brunó Ferenc Straub, a young biochemist working in Albert Szent-Györgyi's laboratory at the Institute of Medical Chemistry at the University of Szeged, Hungary. Following up on the discovery of Ilona Banga & Szent-Györgyi in 1941 that the coagulation only occurs in some myosin extractions and was reversed upon the addition of ATP, Straub identified and purified actin from those myosin preparations that did coagulate. Building on Banga's original extraction method, he developed a novel technique for extracting muscle protein that allowed him to isolate substantial amounts of relatively pure actin, published in 1942. Straub's method is essentially the same as that used in laboratories today. Since Straub's protein was necessary to activate the coagulation of myosin, it was dubbed actin. Realizing that Banga's coagulating myosin preparations contained actin as well, Szent-Györgyi called the mixture of both proteins actomyosin. The hostilities of World War II meant Szent-Gyorgyi was unable to publish his lab's work in Western scientific journals. Actin therefore only became well known in the West in 1945, when their paper was published as a supplement to the Acta Physiologica Scandinavica.
Latin American leaders, including the presidents of Colombia, Guatemala and Mexico, have called for debate about legalizing and regulating aspects of drug production, trade or use. Some Latin leaders are discussing the need to experiment further with decriminalizing possession of drugs. Lawmakers are also proposing to scrap jail terms for growing coca and cannabis. As some Latin American leaders call for legalization of narcotics, Peru, a leading coca grower, remains opposed.
=== Ability to invade plants === Planktonic P. syringae is able to enter plants using its flagella and pili to swim towards a target host. It enters the plant via wounds of natural opening sites, as it is not able to breach the plant cell wall. An example of this is the partnership with the leaf-mining fly Scaptomyza flava, which creates holes in leaves during oviposition that the pathogen can take advantage of. The role of taxis in P. syringae has not been well-studied, but the bacteria are thought to use chemical signals released by the plant to find their host and cause infection.
Collins, who has suffered with urinary incontinence herself, said of the collaboration that she wanted to "help break down the stigma around the subject for women", describing it as "a taboo subject" and said that "it's really sad to know that women are stopping doing their activities because of leaks." Collins said she was "so surprised to find out how many women, just like [her], [were] also experiencing bladder leaks" adding that she had previously "held back on doing things [she enjoyed], like trampolining, riding a bike or working out, and dancing the night away with friends, because [she] was worried about bladder leaks" and that "since learning that pelvic floor exercises can help to manage them, and using pads for those moments when [she needed] more protection, [she] no longer [had] to hold back." Collins continued to collaborate with the brand over the following year to "get women talking and empower those experiencing bladder leaks to live life without compromise" and subsequently discussed her own experience on This Morning. In July 2023, she collaborated with the internet service provider Plusnet, for which she assumed the role of an agony aunt and answered queries from the public in an online video segment titled "Gemma's Dilemmas". Collins said of her role: "From technology mishaps to fashion disasters, I know what it's like to deal with daily frustrations and so this is why I am launching my new campaign, Gemma's Dilemmas, to give my advice to the nation and solve their problems – one step at a time.
Sources: en.wikipedia.org
=== Stickler syndrome === Stickler syndrome (COL11A2): Stickler syndrome is a disorder that causes problems with skeletal development, vision, and hearing. Mutations in the COL11A2 gene cause a form of Stickler in which vision is not affected. COL11A2 mutations cause abnormal production of the pro-alpha2(XI) chain, part of type XI collagen. As a result, type XI collagen is impaired and cannot function properly, causing the skeletal and hearing problems characteristic of Stickler syndrome. The pro-alpha2(XI) chain, however, is not made in the eyes. Instead, another type of collagen chain replaces pro-alpha2(XI) to form type XI collagen in the vitreous of the eye. COL11A2 mutations, therefore, do not affect vision.
=== Synthesis === A variety of synthetic routes to β-hydroxy β-methylbutyric acid have been developed. The first reported chemical syntheses approached HMB by oxidation of alkene, vicinal diol, and alcohol precursors:
BOLD-100, or sodium trans-[tetrachlorobis (1H-indazole)ruthenate(III)], is a ruthenium-based anti-cancer therapeutic in clinical development. As of February 2024, BOLD-100 was being tested in a Phase 1b/2a clinical trial in 117 patients with advanced gastrointestinal cancers in combination with the chemotherapy regimen FOLFOX. BOLD-100 is being developed by Bold Therapeutics Inc.
== Scope == By convention of the nomenclature system, members within an individual SLC family have greater than 20-25% sequence identity to each other. In contrast, the homology between SLC families is very low to non-existent. Hence, the criteria for inclusion of a family into the SLC group is not evolutionary relatedness to other SLC families but rather functional (i.e., an integral membrane protein that transports a solute). The SLC group include examples of transport proteins that are:
The term metalloid has also been used for elements that exhibit metallic lustre and electrical conductivity, and that are amphoteric, such as arsenic, antimony, vanadium, chromium, molybdenum, tungsten, tin, lead, and aluminium. The p-block metals, and nonmetals (such as carbon or nitrogen) that can form alloys with metals or modify their properties have also occasionally been considered as metalloids.
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.
It is a synthetic pentapeptide in the growth hormone secretagogue family and acts as an agonist at the ghrelin receptor. It is handled as a laboratory research compound rather than a naturally occurring hormone.