生长激素促分泌剂 comes up often in conversation and rarely with the context attached. Here we lay out the basics in order, then work through the practical considerations.
Last reviewed on 2026-07-30. Where a claim depends on a specific study, the study is described rather than over-claimed.
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.
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。
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。
| 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 |
Reversed-phase high-performance liquid chromatography is the standard method for purity assessment, most often on a C18 column with a water and acetonitrile gradient and trifluoroacetic acid or formic acid as an ion-pairing agent. Mass spectrometry by electrospray or matrix-assisted laser desorption confirms the expected mass and reveals truncated or modified sequences. Amino acid analysis and sequencing provide orthogonal structural evidence. Typical impurities include deletion sequences, oxidized products, and dimeric species. Detection wavelength, usually 214 or 220 nanometers, should be reported because response factors differ between peptides.
Purity is normally reported as a percentage of total peak area, a figure that does not account for water content, residual solvents, or counterions. Trifluoroacetate and acetate are the most frequent counterions in lyophilized peptides, and they shift the true peptide content away from the mass of the powder. A separate quantitative assay is therefore needed to state content accurately. Certificates of analysis often omit these details, which makes batch-to-batch comparison difficult and limits conclusions drawn when results from different suppliers are compared.
Lyophilized material is generally held at minus twenty degrees Celsius or lower, protected from moisture and light. Repeated excursions to room temperature cause condensation inside the vial and gradual moisture uptake, both of which shorten shelf life. Containers should be allowed to equilibrate before opening so that water does not condense on the solid. Dividing a batch into single-use aliquots reduces freeze-thaw cycling. Solid peptide handled this way is usually considered stable for months to years, while the same material in solution degrades on a much shorter timescale.
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.
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.
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.
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 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.
=== Diabetes stigma === Diabetes stigma describes the negative attitudes, judgment, discrimination, or prejudice against people with diabetes. Often, the stigma stems from the idea that diabetes (particularly Type 2 diabetes) resulted from poor lifestyle and unhealthy food choices rather than other causal factors such as genetics and social determinants of health. Manifestation of stigma can be seen throughout different cultures and contexts. Scenarios include diabetes statuses affecting marriage proposals, workplace-employment, and social standing in communities. Stigma is also seen internally, as people with diabetes can also have negative beliefs about themselves. Often these cases of self-stigma are associated with higher diabetes-specific distress, lower self-efficacy, higher rates of depression, and poorer provider-patient interactions during diabetes care.
PLP forms an imine with the amino acid derivative, facilitating the breaking of the carbon–carbon bond and release of carbon dioxide. The protonation of the amine derived from tryptophan restores the aromaticity of the pyridine ring, leading to the production of 5-hydroxytryptamine and PLP. Serotonin N-acetyltransferase, with histidine residue His122, is hypothesized to deprotonate the primary amine of 5-hydroxytryptamine. This deprotonation allows the lone pair on the amine to attack acetyl-CoA, forming a tetrahedral intermediate. The thiol from coenzyme A then acts as a leaving group when attacked by a general base, producing N-acetylserotonin. The final step in the biosynthesis of melatonin involves the methylation of N-acetylserotonin at the hydroxyl position by SAM, resulting in the production of S-adenosyl homocysteine (SAH) and melatonin.
=== Pharmacokinetics === In the field of pharmacokinetics, steady state refers to the condition in which the rate of drug administration is balanced by the rate of drug elimination, resulting in a stable concentration of the drug in the bloodstream over time. This equilibrium typically occurs following repeated dosing or continuous infusion, and is used to ensure consistent therapeutic drug levels. For most drugs exhibiting first-order kinetics, steady state is generally achieved after approximately four to five half-lives, at which point the changes in plasma concentrations between doses become minimal and predictable. At steady state, drug concentrations do not remain at a single, unchanging value but rather fluctuate within a limited range bounded by peak (Cmax) and trough (Cmin) values across each dosing interval. Ideally, this range is maintained above the minimum effective (therapeutic) concentration and below the threshold for adverse effects, thereby achieving concentrations within the so-called therapeutic window.
== Treatment == Antivenom therapy is the current standard treatment for snake envenoming. In China, the Bungarus multicinctus monovalent antivenom (BMMAV) is produced and, in Taiwan the Neuro bivalent antivenom (NBAV). Both antivenoms are immunoreactive to the neurotoxins found in the venom, including the α-BTX, which neutralize the venom lethality. BMMAV is specifically designed to neutralize the venom of the Bungarus multicinctus, therefore being more efficacious compared to NBAV. On the other hand, NBAV targets the venom from multiple species of snakes that produce neurotoxic effects, including the Bungarus multicinctus. The use of BMMAV or NBAV might differ based on availability, regional protocols and the specific venomous snake that is present in the area.
== Research == Noribogaine was first described in the scientific literature by at least 1958. It was first identified and described as a metabolite of ibogaine by 1995. The first evaluation of noribogaine in humans was published in 2015. In April 2026, the FDA allowed a Phase I clinical study of noribogaine hydrochloride to proceed in the United States.
Sources: en.wikipedia.org
=== Silica aerogel === Silica aerogels are the most common type of aerogel, and the primary type in use or study. It is silica-based and can be derived from silica gel or by a modified Stöber process. Nicknames include frozen smoke, solid smoke, solid air, solid cloud, and blue smoke, owing to its translucent nature and the way light scatters in the material. The lowest-density silica nanofoam weighs 1,000 g/m3, which is the evacuated version of the record-aerogel of 1,900 g/m3. The density of air is 1,200 g/m3 (at 20 °C and 1 atm). The silica solidifies into three-dimensional, intertwined clusters that make up only 3% of the volume. Conduction through the solid is therefore very low. The remaining 97% of the volume is composed of air in extremely small nanopores. The air has little room to move, inhibiting both convection and gas-phase conduction. Silica aerogel also has a high optical transmission of ~99% and a low refractive index of ~1.05. It is very robust with respect to high power input beam in continuous wave regime and does not show any boiling or melting phenomena. This property permits to study high intensity nonlinear waves in the presence of disorder in regimes typically unaccessible by liquid materials, making it promising material for nonlinear optics. This aerogel has remarkable thermal insulative properties, although its thermal conductivity depends on formulation, density, pressure and measurement method.
Distinguishing infections requiring antibiotics from self-limiting ones is clinically challenging. To guide appropriate use of antibiotics and prevent the evolution and spread of antimicrobial resistance, diagnostic tests that provide clinicians with timely, actionable results are needed. Acute fever is a common reason for seeking medical care and a major cause of morbidity and mortality. In areas with decreasing malaria incidence, many febrile patients are inappropriately treated for malaria, and in the absence of a simple diagnostic test to identify alternative causes of fever, clinicians presume that a non-malarial febrile illness is most likely a bacterial infection, leading to inappropriate use of antibiotics. Multiple studies have shown that the use of malaria rapid diagnostic tests without reliable tools to distinguish other fever causes has resulted in increased antibiotic use. Antimicrobial susceptibility testing (AST) can facilitate a precision medicine approach to treatment by helping clinicians to prescribe more effective and targeted antimicrobial therapy. At the same time with traditional phenotypic AST it can take 12 to 48 hours to obtain a result due to the time taken for organisms to grow on/in culture media. Rapid testing, possible from molecular diagnostics innovations, is defined as "being feasible within an 8-h working shift". There are several commercial Food and Drug Administration-approved assays available which can detect AMR genes from a variety of specimen types. Progress has been slow due to a range of reasons including cost and regulation.
== Awards == Advance for Medical Laboratory Professionals received the Corporate Recognition Award from the Pennsylvania chapter of the American Society for Clinical Laboratory Science. In 2006, the trade journal's editor, Matthew Patton, won an award in the Awards for Publication Excellence in the Editorial and Advocacy Writing category
AZD-7268 is a δ-opioid receptor agonist which was under development for the treatment of major depressive disorder but was never marketed. It is taken by mouth. The affinity (Ki) of AZD-7268 for the δ-opioid receptor was reported to be 2.7 nM and its selectivity for this receptor over the μ-opioid receptor was reported to be 2,000-fold. No animal studies of AZD-7268 appear to have been published. In addition to putative antidepressant effects, AZD-7268 might have anxiolytic effects. Structurally, AZD-7268 was derived from SNC-80. Dose-limiting side effects of AZD-7268 in clinical trials included syncope (fainting), hypotension (low blood pressure), and dizziness. AZD-7268 was first described by 2007. Its development was discontinued in 2010. It reached phase 2 clinical trials prior to the discontinuation of its development. No reason was given for the discontinuation of its development. However, the drug was found to be ineffective for major depressive disorder in a phase 2 clinical trial of 231 participants comparing it with placebo and escitalopram. The drug was under development by AstraZeneca.
Sources: en.wikipedia.org
=== Anti-mutagenic === In one study, bemethyl was shown to prevent the mutagenic effect of white asbestos in mice and in cultured human whole blood. A study using mice showed bemethyl to reduce mutation induced by certain mutagenic drugs. Another study using cells from human donors showed Bemethyl to be anticlastogenic (able to minimize chromosome breakages).
=== Physical characteristics === Wound dressings should be stretchable to prevent tearing. Hai Lei et al. demonstrated that poor elasticity and hysteresis in naturally-derived protein-based hydrogels can be remedied by the addition of polyprotein cross-linkers. The flexibility of hydrogels can also be enhanced by incorporating microgels into the matrix. Hydrogel dressings mimic the fibrous nature of native ECM to maintain cell-to-cell communication at the wound bed for tissue regeneration. Self-healing hydrogels automatically and reversibly repair damage done due to mechanical and chemical stress. Self-healing mechanisms can involve "dynamic covalent bonding, non-covalent interactions", and mixed interactions. Covalent interactions involved in self-healing include Schiff base formation and disulfide exchange. Non-covalent interactions are generally less stable and make the hydrogel more sensitive to microenvironmental changes (e.g. pH, temperature). Some hydrogel dressings are self-healing due to mixed mechanisms such as host-guest and protein-ligand interactions. Hydrogel dressings are available in sheet, amorphous, impregnated, or sprayable forms. Sheet-form hydrogel dressings are non-adhesive against the wound and are effective in healing partial-thickness wounds. Amorphous hydrogels are more effective than sheet-form dressings in treatment of full-thickness wounds because they can conform to the shape of the wound bed and facilitate autolytic debridement. Impregnated hydrogel dressings are dry dressings (e.g. gauzes) saturated with an amorphous hydrogel.
Nicotinic acid, or niacin, is an organic compound and a vitamer of vitamin B3, an essential human nutrient. It is produced by plants and animals from the amino acid tryptophan. Nicotinic acid is also a prescription medication. Amounts far in excess of the recommended dietary intake for vitamin functions will lower blood triglycerides and low density lipoprotein cholesterol (LDL-C), and raise blood high density lipoprotein cholesterol (HDL-C, often referred to as "good" cholesterol). There are two forms: immediate-release and sustained-release nicotinic acid. Initial prescription amounts are 500 mg/day, increased over time until a therapeutic effect is achieved. Immediate-release doses can be as high as 3,000 mg/day; sustained-release as high as 2,000 mg/day. Despite the proven lipid changes, nicotinic acid has not been found useful for decreasing the risk of cardiovascular disease in those already prescribed a statin drug. A 2010 review had concluded that nicotinic acid was effective as a mono-therapy, but a 2017 review incorporating twice as many trials concluded that prescription nicotinic acid, while affecting lipid levels, did not reduce all-cause mortality, cardiovascular mortality, myocardial infarctions, nor fatal or non-fatal strokes. Prescription nicotinic acid was shown to cause hepatotoxicity and increase risk of type 2 diabetes. Nicotinic acid prescriptions in the United States had peaked in 2009 at 9.4 million, declining to 800 thousand by 2020. In 2023, it was the 288th most commonly prescribed medication in the US, with more than 500,000 prescriptions.
=== Motility assays === Agarose is sometimes used instead of agar to measure microorganism motility and mobility. Motile species will be able to migrate, albeit slowly, throughout the porous gel and infiltration rates can then be visualized. The gel's porosity is directly related to the concentration of agar or agarose in the medium, so different concentration gels may be used to assess a cell's swimming, swarming, gliding and twitching motility. Under-agarose cell migration assay may be used to measure chemotaxis and chemokinesis. A layer of agarose gel is placed between a cell population and a chemoattractant. As a concentration gradient develops from the diffusion of the chemoattractant into the gel, various cell populations requiring different stimulation levels to migrate can then be visualized over time using microphotography as they tunnel upward through the gel against gravity along the gradient.
== Types == Nano-materials are often categorized as to how many of their dimensions fall in the nanoscale. A nanoparticle is defined a nano-object with all three external dimensions in the nanoscale, whose longest and the shortest axes do not differ significantly. A nanofiber has two external dimensions in the nanoscale, with nanotubes being hollow nanofibers and nanorods being solid nanofibers. A nanoplate/nanosheet has one external dimension in the nanoscale, and if the two larger dimensions are significantly different it is called a nanoribbon. For nanofibers and nanoplates, the other dimensions may or may not be in the nanoscale, but must be significantly larger. In all of these cases, a significant difference is noted to typically be at least a factor of 3. Nanostructured materials are often categorized by what phases of matter they contain. A nanocomposite is a solid containing at least one physically or chemically distinct region or collection of regions, having at least one dimension in the nanoscale. A nanofoam has a liquid or solid matrix, filled with a gaseous phase, where one of the two phases has dimensions on the nanoscale. A nanoporous material is a solid material containing nanopores, voids in the form of open or closed pores of sub-micron lengthscales. A nanocrystalline material has a significant fraction of crystal grains in the nanoscale.
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.
不是。它属于人工合成的五肽，设计上模拟胃饥饿素受体的部分作用，但不存在于人体天然激素谱中。