If you have been reading about GHS-R1a 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 2025-11-07. Numbers and descriptions here follow the published literature rather than marketing material.
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 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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Pentapeptide with C-terminal amide |
| Average mass | Approximately 711.9 Da | Value derived from the formula |
| Appearance | White to off-white powder | Typically supplied as a lyophilised solid |
| Solubility | Soluble in water and aqueous acetonitrile | Dissolution aided by acidic diluents |
| Common synonyms | Ipamorelin; NNC 26-0161 | Code name used in early reports |
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。
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.
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.
This steroid hormone acts on the epithelial cells of the upper small intestine, increasing their capacity to absorb calcium from the gut contents into the blood. The second homeostatic mechanism, with its sensors in the thyroid gland, releases calcitonin into the blood when the blood ionized calcium rises. This hormone acts primarily on bone, causing the rapid removal of calcium from the blood and depositing it, in insoluble form, in the bones. The two homeostatic mechanisms working through PTH on the one hand, and calcitonin on the other can very rapidly correct any impending error in the plasma ionized calcium level by either removing calcium from the blood and depositing it in the skeleton, or by removing calcium from it. The skeleton acts as an extremely large calcium store (about 1 kg) compared with the plasma calcium store (about 180 mg). Longer term regulation occurs through calcium absorption or loss from the gut. Another example are the most well-characterised endocannabinoids like anandamide (N-arachidonoylethanolamide; AEA) and 2-arachidonoylglycerol (2-AG), whose synthesis occurs through the action of a series of intracellular enzymes activated in response to a rise in intracellular calcium levels to introduce homeostasis and prevention of tumor development through putative protective mechanisms that prevent cell growth and migration by activation of CB1 and/or CB2 and adjoining receptors.
==== 1980s ==== The first Starbucks to sell brewed coffee opened in 1982. Later that year, the company hired Howard Schultz, who was behind the push to begin selling brewed coffee. The company opened its first espresso bar in 1984. That year, the original owners of Starbucks, led by Jerry Baldwin, purchased Peet's Coffee. By 1986, the company was operating six stores in Seattle and had begun to sell espresso coffee. Since the founders did not wish to expand too far from their original goal of that centered upon selling arabica coffee beans, Schultz left the company in 1985 to found Il Giornale, a cafe inspired the coffee bars he observed in Milan, Italy. Starbucks was the first investor in this venture, which used its beans in its beverages. In 1987, the original owners sold the Starbucks chain to Schultz, their former director of marketing, who rebranded his Il Giornale coffee outlets as Starbucks and began to expand the company. Also in 1987, Starbucks opened its first locations outside of Seattle, in Waterfront Station in Vancouver, British Columbia, and in Chicago, Illinois. By 1989, there were 46 Starbucks stores located across the Pacific Northwest and Midwest, and the company was roasting more than 2,000,000 pounds (907,185 kg) of coffee annually.
Members of the Organic Anion Transporter (OAT) Family (organic-anion-transporting polypeptides, OATP) are membrane transport proteins or 'transporters' that mediate the transport of mainly organic anions across the cell membrane. Therefore, OATPs are present in the lipid bilayer of the cell membrane, acting as the cell's gatekeepers. OATPs belong to the Solute Carrier Family (SLC) and the major facilitator superfamily. The generalized transport reactions catalyzed by members of the OAT family are: Anion (in) → Anion (out) Anion1 (in) + Anion2 (out) → Anion1 (out) + Anion2 (in)
Sources: en.wikipedia.org
An antibody genetically engineered to neutralize myostatin, stamulumab, which was under development by pharmaceutical company Wyeth, is no longer under development. Some athletes, eager to get their hands on such drugs, turn to the internet where fake "myostatin blockers" are being sold. Resistance exercise and creatine supplementation lead to greater decreases in myostatin levels. Myostatin levels can be temporarily reduced using a cholesterol-conjugated siRNA gene knockdown.
== Causes == The majority of reports are of random lesions, but there are some familial cases, indicating autosomal dominant transmission. Furthermore, connective tissue nevus can present as solitary lesions or be a component of systemic illnesses like tuberous sclerosis, which features shagreen's patches, another form of collagenoma, as an associated feature, or Buschke–Ollendorff syndrome, which is linked to collagenomas and elastomas.
=== Recreational use === At low doses, kratom produces euphoric effects comparable to those of coca. At higher doses, kratom produces opioid-like effects. The onset of effects typically begins within five to ten minutes and lasts for two to five hours. Some anecdotal reports describe increased work capacity, alertness, talkativeness, sociability, increased sexual desire, positive mood, and euphoria following the consumption of kratom. According to the U.S. DEA and a 2020 survey, kratom is used to alleviate pain, anxiety, depression, or opioid withdrawal. In Thailand, a 2007 survey found that the lifetime, past year, and past 30 days kratom consumption rates were 2.32%, 0.81% and 0.57%, respectively, among respondents aged 12–65 years, and that kratom was the most widely used recreational drug in Thailand. Kratom may be mixed with other psychoactive drugs, such as caffeine and codeine. Starting in the 2010s, a tea-based cocktail known as "4×100" became popular among some young people across Southeast Asia and especially in Thailand. It is a mix of kratom leaves, cough syrup, Coca-Cola, and ice. Around 2011, people who consumed the cocktail were often viewed more negatively than users of traditional kratom, but not as negatively as users of heroin. As of 2012, use of the cocktail was a severe problem among youth in three provinces along the border of Malaysia and southern Thailand. In the U.S., as of 2015, kratom was available in outlets such as head shops and over the Internet; the prevalence of its U.S. use was unknown at the time.
Sources: en.wikipedia.org
After exposure, his hand was pale and cold; 30 minutes later the man presented himself to a doctor, with paresthesia in all fingers and the hand still pale and cold. An Allen's test showed a return to normal color after 60 seconds (normal is 5 seconds). By 60 minutes after exposure the hand was normal again, and the patient was discharged without treatment. A week later there was no paresthesia, motor weakness nor sensory deficit.
== Definition == Polycythemia is defined as serum hematocrit (Hct) or hemoglobin (HgB) exceeding normal ranges expected for age and gender, typically Hct >49% in healthy adult men and >48% in women, or HgB >16.5 g/dL in men or >16.0 g/dL in women. The definition is different for neonates and varies by age in children.
== Prior targets == The technique has been used to evolve aptamers of extremely high binding affinity to a variety of target ligands, including small molecules such as ATP and adenosine and proteins such as prions and vascular endothelial growth factor (VEGF). Moreover, SELEX has been used to select high-affinity aptamers for complex targets such as tumor cells, tumor exosomes, or tumor tissue. Clinical uses of the technique are suggested by aptamers that bind tumor markers, GFP-related fluorophores, and a VEGF-binding aptamer trade-named Macugen has been approved by the FDA for treatment of macular degeneration. Additionally, SELEX has been utilized to obtain highly specific catalytic DNA or DNAzymes. Several metal-specific DNAzymes have been reported including the GR-5 DNAzyme (lead-specific), the CA1-3 DNAzymes (copper-specific), the 39E DNAzyme (uranyl-specific) and the NaA43 DNAzyme (sodium-specific). These developed aptamers have seen diverse application in therapies for macular degeneration and various research applications including biosensors, fluorescent labeling of proteins and cells, and selective enzyme inhibition.
Sources: en.wikipedia.org
It is a synthetic five-amino-acid peptide that acts as a growth hormone secretagogue. Three of its residues are non-standard amino acids, and the chain ends in an amide rather than a free acid. The molecule is small enough that it can be characterised by routine peptide analytical techniques.
It has not received marketing approval as a medicine in the United States or the European Union. Supplied material is generally described and handled as a research chemical. Regulatory treatment varies by jurisdiction, and some countries restrict growth hormone secretagogues under sports or medicines legislation.
Earlier secretagogues were associated with broader hormonal responses, including measurable changes in cortisol and prolactin. Reports on this peptide describe a narrower profile in which growth hormone release is the most prominent effect. The observation is influential because it shapes how the compound is compared with other members of the same receptor family.
It acts on the growth hormone secretagogue receptor, GHS-R1a, which is also the receptor for ghrelin. Binding triggers intracellular signaling that promotes growth hormone release from the pituitary. The interaction is the basis for its classification as a secretagogue.