Everything below concerns Ipamorelin. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-10-18. Where a claim depends on a specific study, the study is described rather than over-claimed.
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 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.
| 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 |
Storage recommendations for the dry solid center on low temperature and low moisture, most often -20 °C in a sealed, desiccated container protected from light. Solutions are less stable than the powder and are usually kept cold and used within a short window. Freeze-thaw cycling is a recognized source of loss, and aliquoting before freezing is a standard precaution. These practices derive from general peptide handling principles rather than from a single published stability trial, so exact shelf lives should be treated as approximate.
Analytical confirmation relies on reversed-phase high-performance liquid chromatography, often coupled to mass spectrometry for identity and purity assessment. Mass spectrometry distinguishes the intact molecule from truncation products and from oxidation or deamidation variants that share similar chromatographic retention. Immunoassays appear in some biological studies but can cross-react with related peptides, so they are weaker tools for identity work. Reported purity figures depend heavily on the gradient, detector, and integration method used, which complicates direct comparison between laboratories.
Common solvents for laboratory work include water, buffered saline, and dimethyl sulfoxide. Once dissolved, the peptide is exposed to hydrolysis and oxidation, and alkaline conditions accelerate breakdown. Low-binding plasticware and the addition of a carrier protein reduce losses to container surfaces, which can otherwise be substantial at low concentrations. Solutions are typically kept cold and used within days. Investigators working with the compound generally prepare fresh working dilutions rather than storing dilute stocks, and they avoid repeated warming of the same vial.
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.
Verification of identity and purity relies on analytical methods used across peptide chemistry. Reverse-phase high-performance liquid chromatography separates components by hydrophobicity and provides a purity estimate. Mass spectrometry confirms molecular mass and helps detect modifications. Together these techniques give complementary information about whether a sample matches its expected structure. Results depend on method parameters and reference standards, so reported purity values are meaningful only when the analytical conditions are stated. Consistency between laboratories requires comparable protocols and well-characterized reference materials.
Peptides such as ipamorelin are subject to chemical and physical degradation. Hydrolysis of peptide bonds, oxidation of susceptible residues, and aggregation are common pathways that reduce purity over time. The rate of these processes depends on temperature, moisture, pH, and the number of freeze-thaw cycles a sample undergoes. Because the compound is typically handled as a lyophilized powder, controlling moisture during storage is a central concern. Degradation products can be detected with separation techniques that resolve the parent peptide from related impurities.
=== Pharmacodynamics === Trimebutine is a multimodal drug that acts on many receptors in the body. Its main effects are mediated through inhibition of voltage-gated L-type calcium channels, thereby decreasing calcium influx in smooth muscle in the gut. This mechanism explains its ability to slow peristalsis, which in turn helps with diarrhoea management in IBS patients. Antispasmodic effect is mediated through inhibition of inward rectifier potassium channels and calcium-dependend potassium channels. Moreover, trimebutine and its metabolite N-desmethyltrimebutine exert non-selective antagonistic effect on muscarinic acetylcholine receptors, which is believed to potentiate its antispasmodic effects, as do many other drugs in this class. Moreover, trimebutine and N-desmethyltrimebutine act as weak agonists of opioid receptors, specifically μ-, δ-, and κ-opioid receptor subtypes throughout the gut, which was shown in animal-model studies. Trimebutine exerts its effects in part due to causing a premature activation of phase III of the migrating motor complex in the digestive tract. This mode of action explains trimebutine's ability to mediate gastrointestinal motility in different parts of the gastrointestinal tract, both stimulating and inhibiting spontaneous contractions. In vitro, trimebutine also exhibits antagonistic effects in sodium channels with IC50 equal 8.4 μM and inhibits glutamate release.
== Side effects == The most common side effects include lymphadenopathy (swollen lymph nodes), itching, pain, oedema, and bleeding (for example in the form of bruises or ecchymoses). Allergic reactions are seen in less than 1% of patients. In Peyronie's disease, potential side effects include corporal rupture (penile fracture) or other serious penile injury.
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Sources: en.wikipedia.org
== Function == Kisspeptin is involved in the regulation of endocrine function and the onset of puberty, with activation of the kisspeptin receptor triggering release of gonadotropin-releasing hormone (GnRH), and release of kisspeptin itself being inhibited by oestradiol but enhanced by GnRH. Reductions in kisspeptin levels with age may conversely be one of the reasons behind age-related declines in levels of other endocrine hormones such as luteinizing hormone.
1. FC Lokomotive Leipzig has undergone several reorganizations during its history and has taken several different forms and names. The club was a football department of sports clubs SC Rotation Leipzig and later SC Leipzig, before being reorganized as football club 1. FC Lokomotive Leipzig in 1966.
=== Synthetic alizarin 1868 – 1873 === The development of synthetic alizarin opened up a huge market that was formerly served by natural dye makers. Alizarin was the first dye whose structure chemist determined, and they quickly set it as a target of synthesis, succeeding by 1868. Other chemical components of natural madder were identified and applied by the mid-19th century, including purpurin, which produced a delicate lilac colour, and green alizarin, which was patented in Britain and famously displayed at the 1867 Paris International Exhibition. Similar to aniline dyes, the precursors for Synthetic Alizarin were easily obtainable from coal tar. Germany dominated the synthetic alizarin market, however foreign competition was not non-extant, for example the British Alizarine Company Ltd.
Such a model is described in the figure on the right and involves the utilization of a master equation that includes all steps of amyloid fibril formation, i.e. primary nucleation, fibril elongation, secondary nucleation and fibril fragmentation. The rate constants of the various steps can be determined from a global fit of a number of time courses of aggregation (for example ThT fluorescence emission versus time) recorded at different protein concentrations. The general master equation approach to amyloid fibril formation with secondary pathways has been developed by Knowles, Vendruscolo, Cohen, Michaels and coworkers and considers the time evolution of the concentration
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.
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.