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 2026-05-19. Numbers and descriptions here follow the published literature rather than marketing material.
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.
At the cellular level, ipamorelin binds the growth hormone secretagogue receptor, also called the ghrelin receptor. Activation of this receptor on pituitary somatotroph cells triggers a signaling cascade that leads to release of growth hormone into circulation. Because release follows a pulsatile pattern, studies often report peak concentration and total area under the curve rather than a single time point. Selectivity for this receptor is the property most frequently discussed in comparative work.
Long-term storage of the dry powder is typically at minus twenty degrees Celsius or lower, protected from light and moisture. Solutions are commonly kept frozen and thawed only once, because repeated freeze-thaw cycles can promote aggregation and loss of measurable peptide content. Buffers near neutral pH are preferred over strongly acidic or strongly basic conditions. Shipping at ambient temperature is acceptable for short periods when the powder remains sealed and desiccated.
Identity and purity are assessed by complementary methods rather than a single test. Reversed-phase high-performance liquid chromatography separates the peptide from related impurities and reports a percentage purity. Mass spectrometry, most often with electrospray ionization, confirms the expected molecular mass and detects sequence-related variants. Amino acid analysis can verify composition, while water content and residual counterion measurements support the mass balance of a batch. Stability studies under accelerated conditions are used to estimate shelf life, though such estimates carry uncertainty for long-term storage.
| Property | Value | Notes |
|---|---|---|
| Chemical class | Synthetic pentapeptide | Growth hormone secretagogue family |
| Sequence | Aib-His-D-2-Nal-D-Phe-Lys-NH2 | Contains two non-natural residues |
| Molecular formula | C38H49N9O5 | Free base form |
| Molecular weight | 711.85 g/mol | Calculated from formula |
| Primary target | GHS-R1a ghrelin receptor | Agonist activity |
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.
Compared with earlier growth hormone secretagogues such as GHRP-6 and hexarelin, ipamorelin has been reported to produce less stimulation of adrenocorticotropic hormone, cortisol, and prolactin in animal and early human studies. This selectivity is usually attributed to differences in receptor subtype interactions and to the tissue distribution of the receptor. Effects on appetite appear weaker than those of ghrelin itself, although the supporting evidence base is small. Whether these differences produce a distinct clinical profile remains an open question, since controlled human trials are limited.
Lyophilized ipamorelin is generally held at minus twenty degrees Celsius or colder, protected from light and moisture. In solution the peptide is less stable, and degradation proceeds through hydrolysis of the amide backbone, oxidation of the histidine residue, and aggregation. Repeated freeze-thaw cycles accelerate these processes, so dividing material into single-use aliquots before freezing is common practice in research settings. Buffered formulations near neutral pH tend to show the slowest degradation, while strongly acidic or basic conditions raise hydrolysis rates. Stability data specific to ipamorelin are sparse, and much guidance is extrapolated from other short peptides.
Quality control for research-grade ipamorelin is not governed by a single harmonized pharmacopeial monograph, so certificates of analysis vary between suppliers. Common tests include appearance, solubility, water content, peptide content by quantitative amino acid analysis, and residual counterion measurement. Independent verification by an outside laboratory is often used to confirm identity and purity claims. Salt form, counterion content, and residual solvent levels are frequently unspecified, which complicates direct comparison between lots and leaves reproducibility partly unresolved.
Identity and purity assessment of ipamorelin relies mainly on reversed-phase high-performance liquid chromatography with ultraviolet detection near 214 nanometers, a wavelength where the peptide backbone absorbs. Mass confirmation is typically obtained by electrospray ionization mass spectrometry or by liquid chromatography coupled to mass spectrometry, comparing the observed mass with the calculated value. Amino acid analysis and peptide mapping after enzymatic digestion can confirm the sequence. Impurity profiles include deletion peptides, truncated fragments, and oxidation products, reported as relative area percentages.
== Further reading == David L. Heiserman (1968). Light -Emitting Diodes (PDF). Electronics World. Shuji Nakamura; Gerhard Fasol; Stephen J Pearton (2000). The Blue Laser Diode: The Complete Story. Springer Verlag. ISBN 978-3-540-66505-2.
== Clinical significance == In vascular smooth muscle cell (VSMC), ADAMTS7 mediates VSMC migration, which plays an essential role during the development of atherosclerosis and restenosis. This proatherogenic effect has been demonstrated to specifically require the catalytic protease activity of ADAMTS7, as mice expressing a catalytically inactive mutant of the enzyme (E373Q) are similarly protected against atherosclerosis. Adamts7 deficiency in both the Ldlr−/– and Apoe−/– hyperlipidemic mouse models markedly attenuates formation of atherosclerotic lesions; furthermore, wire-injury experiments in the Adamts7−/– mouse show reduced neointima formation. The association of ADAMTS7 with atherosclerosis suggests that inhibition of ADAMTS7 should be atheroprotective in humans. A negative correlation between the expression levels of specific miRNAs and ADAMTS7 is observed in normal tissues but not in disease tissues, implying an altered miRNA-target interaction in the disease state. Accordingly, expression profiles of these miRNAs and ADAMTS7 may be useful diagnostic tools to differentiate cancer and lichen planus from normal tissues. ADAMTS7 has also been identified as a putative oncogene and reported to be mutated exclusively in Asians, which may have implications for the prevention and treatment of hepatocellular carcinoma. In addition, ADAMTS7 plays a crucial role in the pathogenesis of arthritis. For example, the FGF2/p65/miR-105/Runx2/ADAMTS axis is reportedly involved in osteoarthritis (OA) pathogenesis.
== History == The predecessor to the CAD, termed an evaporative electrical detector, was first described by Kaufman in 2002 at TSI Inc in US patent 6,568,245 and was based on the coupling of liquid chromatographic approaches to TSI's electrical aerosol measurement (EAM) technology. At around the same time Dixon and Peterson at California State University were investigating the coupling of liquid chromatography to an earlier version of TSI's EAM technology, which they called an aerosol charge detector. Subsequent collaboration between TSI and ESA Biosciences Inc. (now part of Thermo Fisher Scientific), led to the first commercial instrument, the Corona CAD, which received both the Pittsburgh Conference Silver Pittcon Editor's Award (2005) and R&D 100 award (2005). Continued research and engineering improvements in product design resulted in CADs with ever increasing capabilities. The newest iterations of the CAD are the Thermo Scientific Corona Veo Charged Aerosol Detector, Corona Veo RS Charged Aerosol Detector and Thermo Scientific Vanquish Charged Aerosol Detectors.
==== With thermal imaging ==== Drawing on successful medical research that used thermal imaging to appraise the severity of burns, in 1997 a different group of Canadian researchers used similar technology on recently branded cattle. This was done to determine whether the wounds created by hot and freeze branding remained equally swollen and presumably painful, or if there was a difference in healing between the two methods. Thirty heifers were randomly selected for either hot or freeze branding. Two 25 cm2 patches were shaved on each heifer and the higher of the two was selected for branding, with the other serving as a control. Fifteen of the heifers were hot branded for 3–4 seconds and the others Cryo-branded with copper irons for 22 seconds. A thermographic camera able to measure skin temperatures to ± 0.1 °C was then used to observe the wound and the control at intervals. This gave a proxy for tissue inflammation and, it was thought, the animal's level of discomfort. The temperature of the control site was then subtracted from the temperature of the branding site to give the difference between the two techniques. The data indicated that both methods caused tissue damage, with the freeze brands being warmer and more inflamed than the hot brands at two and eight hours. However, this trend soon reversed and the inflammatory responses triggered by the brandings appeared to diverge rapidly. Hot brand wounds were still significantly warmer than controls one week later, by which time the freeze-branded areas were no warmer than their controls.
Sources: en.wikipedia.org
== Diagnostic use == S100B is secreted by astrocytes or can spill from injured cells and enter the extracellular space or bloodstream. Serum levels of S100B increase in patients during the acute phase of brain damage. Over the last decade, S100B has emerged as a candidate peripheral biomarker of blood–brain barrier (BBB) permeability and CNS injury. Elevated S100B levels accurately reflect the presence of neuropathological conditions including traumatic head injury or neurodegenerative diseases. Normal S100B levels reliably exclude major CNS pathology. Its potential clinical use in the therapeutic decision making process is substantiated by a vast body of literature validating variations in serum 100B levels with standard modalities for prognosticating the extent of CNS damage: alterations in neuroimaging, cerebrospinal pressure, and other brain molecular markers (neuron specific enolase and glial fibrillary acidic protein). However, more importantly, S100B levels have been reported to rise prior to any detectable changes in intracerebral pressure, neuroimaging, and neurological examination findings. Thus, the major advantage of using S100B is that elevations in serum or CSF levels provide a sensitive measure for determining CNS injury at the molecular level before gross changes develop, enabling timely delivery of crucial medical intervention before irreversible damage occurs. S100B serum levels are elevated before seizures suggesting that BBB leakage may be an early event in seizure development.
Mendelevium is a synthetic chemical element; it has symbol Md (formerly Mv) and atomic number 101. A metallic radioactive transuranium element in the actinide series, it is the first element by atomic number that currently cannot be produced in macroscopic quantities by neutron bombardment of lighter elements. It is the thirteenth actinide, the ninth transuranic element, and the first transfermium; it is named after Dmitri Mendeleev, the father of the periodic table. Like all the transfermiums, it can only be produced in particle accelerators by bombarding lighter elements with charged particles. The element was first produced in 1955 by bombarding einsteinium with alpha particles, the method still used today. Using commonly-available microgram quantities of einsteinium-253, over a million mendelevium atoms may be made each hour. The chemistry of mendelevium is typical for the late actinides, with a dominant +3 oxidation state but also a +2 oxidation state accessible in solution. All known isotopes of mendelevium have short half-lives; there are currently no uses for it outside basic scientific research, and only small amounts are produced.
Lately Intelligence Officer, Home Office. For services to Border Security. The Reverend Christopher Richard Colledge. For services to the community in Bournemouth, Dorset. Alan Collier. Director, Procurement and Sustainability, Norfolk County Council. For services to Local Government. Dr. Michael Patrick Collins. Lately Science Lead on EU and International Science Partnerships, Department for Environment, Food and Rural Affairs. For services to International Science Policy. Denise Cooke. Administrative Officer, Maritime and Coastguard Agency. For Public Service. Laura Coryton. Tampon Tax Campaigner, Author and Co-Founder, Sex Ed Matters. For services to Charitable Campaigning. Margaret Irene Cosin. Lately Member, Dover District Council. For Political and Public Service. Stuart Samuel Cossar. Investigation Manager, Police Service of Scotland. For services to the Investigation and to the Bereaved Families of the Lockerbie Air Disaster. Anne Marie Coulter. Volunteer, Summerhill Community Centre. For services to the community in Dumfries. Samuel Robert John Cousley. Head of Seafarers, Department for Transport. For services to Seafarers. Professor Rachel Elizabeth Cowgill. Professor of Music, University of York. For services to Culture, to Education and to the Arts. John Hubert Cox. Chair, Joseph Cox Charity. For services to Homeless People in Manchester. Maureen Joan Cox. For charitable services in the London Borough of Hackney. Vanessa Sara Crocker. Co-Founder, Spread a Smile. For services to Seriously and Terminally Ill Children and their Families. Daniel Steven Paul Croft.
Sources: en.wikipedia.org
It is a synthetic pentapeptide in the growth hormone secretagogue family. The chain contains five residues, two of which are non-natural amino acids.
It acts as an agonist at the growth hormone secretagogue receptor, also known as the ghrelin receptor. Binding at pituitary somatotroph cells promotes growth hormone release.
Early studies report weaker effects on cortisol, prolactin, and appetite than compounds such as GHRP-6. The size of that difference in humans is not firmly established.
Dry powder is held at minus twenty degrees Celsius or colder, away from light and moisture. Sealed vials under inert gas limit degradation during storage.