If you have been reading about mass spectrometry 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 2026-06-06. Numbers and descriptions here follow the published literature rather than marketing material.
Ipamorelin is a synthetic pentapeptide first described in the 1990s by researchers at Novo Nordisk during a program to develop selective growth hormone secretagogues. Its sequence is Aib-His-D-2-Nal-D-Phe-Lys-NH2, incorporating two non-natural residues, alpha-aminoisobutyric acid and D-2-naphthylalanine. The C-terminus is amidated, and the material is supplied as a white lyophilized powder. The molecular formula is C38H49N9O5 and the monoisotopic mass is approximately 711.85 daltons. The short chain and modified residues give it greater resistance to enzymatic degradation than many larger peptide hormones.
At the molecular level, ipamorelin acts as an agonist at the growth hormone secretagogue receptor type 1a, the same G protein-coupled receptor that binds ghrelin. Receptor activation couples to Gq/11 signaling, raising intracellular calcium through inositol trisphosphate and diacylglycerol, which in turn promotes exocytosis of growth hormone from pituitary somatotroph cells. Ipamorelin binds this receptor with high affinity and shows weak activity at other secretagogue-related targets in vitro. Its action requires the intact receptor and is not reversed by growth hormone-releasing hormone antagonists.
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.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Pentapeptide with amidated C-terminus |
| Molecular weight | 711.85 g/mol | Monoisotopic mass |
| Primary receptor | GHS-R1a | Ghrelin receptor, Gq/11 coupled |
| Peptide class | Synthetic pentapeptide | Contains two non-natural residues |
| Reported selectivity | Lower cortisol and prolactin effect | Observed in animal and early human work |
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.
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.
Lyophilized material is generally stored frozen and protected from light and moisture. Typical recommendations place dry powder at temperatures well below freezing, while reconstituted solutions are kept cold and used within a defined window. Repeated freezing and thawing should be avoided because it can promote aggregation and loss of material. The choice of solvent matters as well; compatibility with the intended diluent should be checked before preparation. These handling practices aim to preserve both the quantity and the integrity of the peptide.
== Early life and research == Hafezi was born in Remscheid, Germany in 1967, but he moved to Fribourg in Switzerland in 1981. He studied medicine in Fribourg and Bern, obtaining his Doctorate of Medicine at the Inselspital Bern under Prof. Dr. med Peter Weidmann, before going on in 1993, to undertake a two-year postgraduate course in Experimental Medicine and Biology at the University of Zürich. Hafezi spent three additional years at the University Hospital of Zurich, where he worked in the Laboratory for Retinal Cell Biology, which was part of the Department of Ophthalmology. Whilst studying in the Zürich laboratory, Hafezi identified the first known gene, c-Fos, that the absence of which could completely suppress light-induced apoptotic retinal degeneration. The group's findings were featured on the cover of the April 1997 edition of Nature Medicine. Hafezi then focused on a number of areas of cellular and retinal degeneration, in particular, light-induced photoreceptor death in the absence of p53 and JunD/AP-1, work that was published in IOVS and Cell Death & Differentiation, respectively. c-Fos and Fra1 are both components of the transcription factor AP-1, and in the year 2000, Hafezi and his colleagues presented work that showed that, in genetically engineered mice that express Fra1 where c-Fos is usually expressed, Fra1 can function in lieu of c-Fos to promote light-induced retinal photoreceptor death – work that was published in Genes & Development.
== Traditional use == Peach gum has been documented in traditional Chinese medicine texts, including the Tang Bencao (Tang Materia Medica) and Li Shizhen's Bencao Gangmu (Compendium of Materia Medica) from the Ming Dynasty. Historical texts describe its use for treating urinary issues and other conditions, though these traditional uses have not been validated by modern scientific research.
Initially, by analogy with neutron magic number 126, the next proton shell was also expected at element 126, too far beyond the synthesis capabilities of the mid-20th century to get much theoretical attention. In 1966, new values for the potential and spin–orbit interaction in this region of the periodic table contradicted this and predicted that the next proton shell would instead be at element 114, and that nuclei in this region would be relatively stable against spontaneous fission. The expected closed neutron shells in this region were at neutron number 184 or 196, making 298Fl and 310Fl candidates for being doubly magic. 1972 estimates predicted a half-life of around 1 year for 298Fl, which was expected to be near an island of stability centered near 294Ds (with a half-life around 1010 years, comparable to 232Th). After making the first isotopes of elements 112–118 at the turn of the 21st century, it was found that these neutron-deficient isotopes were stabilized against fission. In 2008 it was thus hypothesized that the stabilization against fission of these nuclides was due to their oblate nuclei, and that a region of oblate nuclei was centred on 288Fl. Also, new theoretical models showed that the expected energy gap between the proton orbitals 2f7/2 (filled at element 114) and 2f5/2 (filled at element 120) was smaller than expected, so element 114 no longer appeared to be a stable spherical closed nuclear shell.
Sources: en.wikipedia.org
A history of widespread pain lasting more than three months – affecting all four quadrants of the body, i.e., both sides and above and below the waist. Tender points – there are 18 designated possible tender points (although a person with the disorder may feel pain in other areas as well). The ACR criteria for the classification of patients were originally established as inclusion criteria for research purposes and were not intended for clinical diagnosis, but have later become the de facto diagnostic criteria in the clinical setting. A controversial study was done by a legal team looking to prove their client's disability based primarily on tender points, and their widespread presence in non-litigious communities prompted the lead author of the ACR criteria to question the usefulness of tender points in diagnosis. Use of control points has been used to cast doubt on whether a person has fibromyalgia, and to claim the person is malingering. In 2010, the American College of Rheumatology approved provisional revised diagnostic criteria for fibromyalgia that eliminated the 1990 criteria's reliance on tender point testing. The revised criteria used a widespread pain index (WPI) and symptom severity scale (SSS) in place of tender point testing under the 1990 criteria. The WPI counts up to 19 general body areas in which the person has experienced pain in the preceding week. The SSS rates the severity of the person's fatigue, unrefreshed waking, cognitive symptoms, and general somatic symptoms, each on a scale from 0 to 3, for a composite score ranging from 0 to 12.
== Pronunciation == Pronunciation follows convention outside the medical field, in which acronyms are generally pronounced as if they were a word (JAMA, SIDS), initialisms are generally pronounced as individual letters (DNA, SSRI), and abbreviations generally use the expansion (soln. = "solution", sup. = "superior"). Abbreviations of weights and measures are pronounced using the expansion of the unit (mg = "milligram") and chemical symbols using the chemical expansion (NaCl = "sodium chloride"). Some initialisms deriving from Latin may be pronounced either as letters (qid = "cue eye dee") or using the English expansion (qid = "four times a day").
"It is the beginningless round of rebirths that is called the 'Wheel of the round of rebirths' (saṃsāracakka). Ignorance (avijjā) is its hub (or nave) because it is its root. Ageing-and-death (jarā-maraṇa) is its rim (or felly) because it terminates it. The remaining ten links [of Dependent Origination] are its spokes [i.e. saṅkhāra up to the process of becoming, bhava]."
Sources: en.wikipedia.org
It is a synthetic pentapeptide belonging to the growth hormone secretagogue family. Its principal characterized target is the ghrelin receptor, also called GHS-R1a. The molecule contains non-natural amino acids and an amidated C-terminus.
Both act at the same G protein-coupled receptor, but ipamorelin is a short synthetic peptide with modified residues rather than the natural 28-amino-acid hormone. Reports describe weaker effects on appetite and on cortisol or prolactin release than those seen with ghrelin. Its resistance to enzymatic breakdown also differs from that of the natural ligand.
Receptor binding and downstream calcium signaling are well characterized in cell-based systems. Effects measured in whole organisms are less consistent across studies and species. The extent to which selective receptor behavior drives the observed hormonal profile is still debated.
It is reported as the percentage of total peak area in a reversed-phase chromatogram. That number does not reflect water content, residual solvents, or counterions. The actual peptide content is therefore lower than the stated purity figure suggests.