If you have been reading about selectivity 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 2026-01-18. 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 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.
Activity is mediated mainly through the growth hormone secretagogue receptor, now generally called the ghrelin receptor or GHS-R1a. Binding at this G-protein-coupled receptor triggers phospholipase C signaling, calcium mobilization, and release of growth hormone from pituitary somatotrophs. Reports describe less pronounced stimulation of adrenocorticotropic hormone and prolactin compared with earlier secretagogues such as hexarelin or GHRP-6. Selectivity figures vary between assay systems, so the degree of separation from other secretagogues is an area of ongoing comparison rather than a fixed constant.
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.
| 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 |
Reversed-phase high-performance liquid chromatography is the standard tool for assessing purity. Detection near 214 nanometers captures the peptide backbone, and the resulting chromatogram shows the main peak alongside related impurities. Electrospray ionization mass spectrometry confirms molecular mass and supports sequence verification. Common degradation products include oxidized residues, deamidated forms, and truncated fragments, each appearing as a distinct peak or shoulder in the trace.
Quality claims for research peptides vary widely across suppliers. A certificate of analysis should list purity by chromatography, the mass found by spectrometry, and the analytical conditions used. Independent testing at a third-party laboratory is a common way to check identity and purity, because documents alone cannot confirm what is inside a vial. Purity figures describe the proportion of the target peptide among detected species, and they say nothing about biological activity or sterility.
Lyophilized ipamorelin powder is the form usually supplied for laboratory work. Kept dry, protected from light, and held at minus 20 degrees Celsius or below, it remains stable for extended periods, often measured in years. Once dissolved, the peptide degrades faster through hydrolysis, oxidation, and deamidation, so solutions are typically refrigerated and used within weeks. Repeated freeze-thaw cycles and exposure to alkaline conditions accelerate loss of the parent compound.
=== Economics === The Australian Pharmaceutical Benefits Advisory Committee (PBAC) considered a March 2014 application by the manufacturer for inclusion of brentuximab vedotin under a Pharmaceutical Benefits Scheme Section 100 (Efficient Funding of Chemotherapy) arrangement. While this application was accepted, the committee noted that on the basis of inadequate cost-benefit, the medicine would not be made available more generally for the first-line treatment of relapsed or refractory systemic anaplastic large cell lymphoma (sALCL).
=== Edible plants and mushrooms === In drying seeds, serotonin production is a way to get rid of the buildup of poisonous ammonia. The ammonia is collected and placed in the indole part of L-tryptophan, which is then decarboxylated by tryptophan decarboxylase to give tryptamine, which is then hydroxylated by a cytochrome P450 monooxygenase, yielding serotonin. However, since serotonin is a major gastrointestinal tract modulator, it may be produced in the fruits of plants as a way of speeding the passage of seeds through the digestive tract, in the same way as many well-known seed and fruit associated laxatives. Serotonin is found in mushrooms, fruits, and vegetables. The highest values of 25–400 mg/kg have been found in nuts of the walnut (Juglans) and hickory (Carya) genera. Serotonin concentrations of 3–30 mg/kg have been found in plantains, pineapples, banana, kiwifruit, plums, and tomatoes. Moderate levels from 0.1–3 mg/kg have been found in a wide range of tested vegetables. Serotonin is one compound of the poison contained in stinging nettles (Urtica dioica), where it causes pain on injection in the same manner as its presence in insect venoms. It is also naturally found in Paramuricea clavata, or the Red Sea Fan. Serotonin and tryptophan have been found in chocolate with varying cocoa contents. The highest serotonin content (2.93 μg/g) was found in chocolate with 85% cocoa, and the highest tryptophan content (13.27–13.34 μg/g) was found in 70–85% cocoa. The intermediate in the synthesis from tryptophan to serotonin, 5-hydroxytryptophan, was not found.
Pneumatic transportation was invented by William Murdoch around 1799. Capsule pipelines were first used in the Victorian era, to transmit telegrams from telegraph stations to nearby buildings. The system is known as pneumatic dispatch. In 1854, Josiah Latimer Clark was issued a patent "for conveying letters or parcels between places by the pressure of air and vacuum". In 1853, he installed a 220-yard (200 m) pneumatic system between the London Stock Exchange in Threadneedle Street, London, and the offices of the Electric Telegraph Company in Lothbury. The Electric Telegraph Company used the system to acquire stock prices and other financial information to pass to subscribers of their service over their telegraph wires. This enabled much more rapid dissemination of information, as without the pneumatic system the company would have had to employ runners to carry messages between the two buildings, or else employ trained telegraph operators within the Stock Exchange. In the mid-1860s the company installed similar systems to local stock exchanges in Liverpool, Birmingham, and Manchester. After the telegraphs were nationalised in Britain the pneumatic system continued to be expanded under Post Office Telegraphs.
Sources: en.wikipedia.org
A compartment kiln is filled with a static batch of timber through which air is circulated. In these types of kiln, the timber remains stationary. The drying conditions are successively varied according to the type of timber being dried. This drying method is well suited to the needs of timber companies, which have to dry timbers of varied species and thickness, including refractory hardwoods that are more liable than other species to check and split. The main elements of chamber drying are:
Extractive electrospray ionization is a spray-type, ambient ionization method that uses two merged sprays, one of which is generated by electrospray. Laser-based electrospray-based ambient ionization is a two-step process in which a pulsed laser is used to desorb or ablate material from a sample and the plume of material interacts with an electrospray to create ions. For ambient ionization, the sample material is deposited on a target near the electrospray. The laser desorbs or ablates material from the sample which is ejected from the surface and into the electrospray which produces highly charged ions. Examples are electrospray laser desorption ionization, matrix-assisted laser desorption electrospray ionization, and laser ablation electrospray ionization.
In 1897, John Jacob Abel (1857–1938) of Johns Hopkins University, the first chairman of the first US department of pharmacology, found a compound called epinephrine with the molecular formula of C17H15NO4. Abel claimed his principle from adrenal gland extract was active. In 1900, Jōkichi Takamine (1854–1922), a Japanese chemist, worked with his assistant, Keizo Uenaka (1876–1960), to purify a 2000 times more active principle than epinephrine from the adrenal gland, named adrenaline with the molecular formula C10H15NO3. Additionally, in 1900 Thomas Aldrich of Parke-Davis Scientific Laboratory also purified adrenaline independently. Takamine and Parke-Davis later in 1901 both got the patent for adrenaline. The fight for terminology between adrenaline and epinephrine was not ended until the first adrenaline structural discovery by Hermann Pauly (1870–1950) in 1903 and the first adrenaline synthesis by Friedrich Stolz (1860–1936), a German chemist in 1904. They both believed that Takamine's compound was the active principle while Abel's compound was the inactive one. Stolz synthesized adrenaline from its ketone form (adrenalone).
== Management == Treatment requires identifying and removing any causative medications and correcting any underlying electrolyte abnormalities. While TdP often self-resolves, cardioversion may be indicated if patients become hemodynamically unstable, as evidenced by signs such as hypotension, altered mental status, chest pain, or heart failure. Intravenous magnesium sulfate has been proven to be highly effective for both the treatment and prevention of TdP. Managing patients with TdP is dependent on the patient's stability. Vital signs, level of consciousness, and current symptoms are used to assess stability. Patients who are stable should be managed by removing the underlying cause and correcting electrolyte abnormalities, especially hypokalemia. An EKG should be obtained, a cardiac monitor should be attached, IV access should be established, supplemental oxygen should be given, and blood samples should be sent for appropriate studies. Patients should be continually re-evaluated for signs of deterioration until the TdP resolves. In addition to correcting the electrolyte abnormalities, magnesium given intravenously has also been shown to be helpful. Magnesium sulfate given as a 2 g IV bolus mixed with D5W can be given over a period of 15 minutes in patients without cardiac arrest Atrial pacing or administering isoproterenol can normalize the heart rate. Unstable patients exhibit signs of chest pain, hypotension, elevated heart rate, and/or heart failure. Patients who develop cardiac arrest will be pulseless and unconscious.
Sources: en.wikipedia.org
In 1957, Polish foreign minister Adam Rapacki proposed the Rapacki Plan for a nuclear free zone in central Europe. Public opinion tended to be favourable in the West, but it was rejected by leaders of West Germany, Britain, France and the United States. They feared it would leave the powerful conventional armies of the Warsaw Pact dominant over the weaker NATO armies. During November 1958, Khrushchev made an unsuccessful attempt to turn all of Berlin into an independent, demilitarized "free city". He gave the United States, Great Britain and France a six-month ultimatum to withdraw their troops from the sectors of West Berlin, or he would transfer control of Western access rights to the East Germans. Khrushchev earlier explained to Mao Zedong that "Berlin is the testicles of the West. Every time I want to make the West scream, I squeeze on Berlin." NATO formally rejected the ultimatum in mid-December and Khrushchev withdrew it in return for a Geneva conference on the German question.
=== Cannibalism === On 23 July 1988, Gibson ate the flesh of another person in public. Because England does not have a specific law against cannibalism, he legally ate a canapé of donated human tonsils in Walthamstow High Street, London. A year later, on 15 April 1989, he publicly ate a slice of human testicle. When he tried to eat another slice of human testicle as "hors d'oeuvre" at the Pitt International Galleries in Vancouver on 14 July 1989, the police confiscated the testicle. However, the charge of publicly exhibiting a disgusting object was dropped, and two months later he finally ate the piece of human testicle on the steps of the Vancouver court house.
Digital television (DTV) transmission systems, which replaced older analog television in a transition beginning in 2006, use image compression and high-efficiency digital modulation such as OFDM and 8VSB to transmit HDTV video within a smaller bandwidth than the old analog channels, saving scarce radio spectrum space. Therefore, each of the 6 MHz analog RF channels now carries up to 7 DTV channels – these are called "virtual channels". Digital television receivers have different behavior in the presence of poor reception or noise than analog television, called the "digital cliff" effect. Unlike analog television, in which increasingly poor reception causes the picture quality to gradually degrade, in digital television picture quality is not affected by poor reception until, at a certain point, the receiver stops working and the screen goes black.
=== Limitations === The UK Government's Department of Health compiled a factsheet in 2014, in which it is stated that the key limitations to well-being, quality of life and life satisfaction research are that:
The D-dimer assay depends on the binding of a monoclonal antibody to a particular epitope on the D-dimer fragment. Several detection kits are commercially available; all of them rely on a different monoclonal antibody against D-dimer. For some of these, the area of the D-dimer to which the antibody binds is known. The binding of the antibody is then measured quantitatively by one of various laboratory methods.
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 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.