A practical reference on growth hormone secretagogue: what it is, how it behaves, what the literature reports, and where the honest uncertainties sit.
Reviewed 2025-10-06. Anything still debated is marked as such rather than presented as settled.
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.
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.
Identity and purity assessment for a research peptide of this kind typically combines reversed-phase high-performance liquid chromatography with mass spectrometry. The chromatographic run separates related impurities and yields a purity percentage, while electrospray ionization or matrix-assisted laser desorption mass spectrometry confirms the expected molecular mass. Amino acid analysis or tandem mass spectrometry sequencing can add confidence when material is intended for quantitative work. Laboratories differ in how they calculate and report purity, so figures from different sources are not always directly comparable.
Lyophilized material is generally stored cold and dry, with desiccant, and protected from light. In solution the peptide is more vulnerable: the histidine side chain can oxidize, and repeated freeze-thaw cycles promote aggregation and loss of material to container surfaces. A mildly acidic aqueous buffer is often used for short-term handling because it limits several degradation routes. Accurate prediction of long-term stability under a given set of conditions is difficult, and published stability data remain sparse.
| 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 |
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.
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.
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.
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.
=== Ca–Ce === David S. Cafiso (b. 1952). American biochemist at the University of Virginia, with research focusing on membranes and membrane proteins. Graham Cairns-Smith FRSE (1931–2016) Scottish organic chemist and molecular biologist at the University of Glasgow. John Cairns FRS (1922–2018) was a British physician and molecular biologist at the Harvard School of Public Health. T. Colin Campbell (b. 1934). American biochemist at Cornell University, specializing in the effect of nutrition on long-term health. David E. Cane (b. 1944). American biological chemist at Brown University, recognized for his work on the biosynthesis of natural products, particularly terpenoids and polyketides. Lewis C. Cantley (b. 1949). American cell biologist and biochemist at Harvard Medical School, who has made significant advances to the understanding of cancer metabolism. Member Natl. Acad. Sci. USA. Charles Cantor (b. 1942). American biophysicist at Boston University, he developed the method of pulse field gel electrophoresis, and was formerly Director of the Human Genome Project. He is known also for his book series Biophysical Chemistry with Paul Schimmel John Carbon (PhD 1955). American cellular biologist at UC Santa Barbara, known for development of techniques for making genome libraries. Member Natl. Acad. Sci. USA. María Luz Cárdenas (b. 1944). French biochemist of Chilean origin at the CNRS, Marseille, known for work on mammalian hexokinases. H. E. Carter (1910–2007). American biochemist, at the University of Illinois, known for determining the structure of threonine. Member Natl.
An extensive body of recent experimental research on laboratory animals and documented skeletons has confirmed that habitual muscle recruitment can indeed significantly affect entheseal variation in three-dimensional (3D) morphology - especially when this is quantified based on repeatable and validated morphometric approaches (such as for example V.E.R.A. 1.0 - first introduced in 2016 - and V.E.R.A. 2.0). In contrast, previous research relying on the use of traditional methods (visual scoring systems) has shown that processes associated with aging may have a greater impact than occupational stresses. It has also been shown that geometric changes to bone structure (described above) and scored entheseal changes differ in their underlying cause with the latter little affected by occupation. Joint changes, including osteoarthritis, have been used to infer occupations, but in general these are also manifestations of the aging process. Markers of occupational stress, which include morphological changes to the skeleton and dentition as well as joint changes at specific locations have been widely used to infer specific (rather than general) activities. Such markers are often based on single cases described in late nineteenth century clinical literature. One such marker has been found to be a reliable indicator of lifestyle: the external auditory exostosis also called surfer's ear, which is a small bony protuberance in the ear canal that occurs in those working in proximity to cold water.
To overcome this effect, a new index was created, named the Equatorial Southern Oscillation Index (EQSOI). To generate this index, two new regions, centered on the Equator, were defined. The western region is located over Indonesia and the eastern one over the equatorial Pacific, close to the South American coast. However, data on EQSOI goes back only to 1949. Sea surface height (SSH) changes up or down by several centimeters in Pacific equatorial region with the ENSO: El Niño causes a positive SSH anomaly (raised sea level) because of thermal expansion while La Niña causes a negative SSH anomaly (lowered sea level) via contraction.
Sources: en.wikipedia.org
Promethium is one of the two elements of the first 82 elements that has no stable isotopes. This is a rarely occurring effect of the liquid drop model. Namely, promethium does not have any beta-stable isotopes, as for any mass number, it is energetically favorable for a promethium isotope to undergo positron emission or beta decay, respectively forming a neodymium or samarium isotope which has a higher binding energy per nucleon. The other element for which this happens is technetium (Z = 43).
== Intellectual Property == In May 2013, Boehringer Ingelheim of Germany applied for a Methods of Treatment, Pharmaceutical Compositions and uses thereof patent. This patent application included SGLT2 inhibitor ipragliflozin. In April 2014, Boehringer Ingelheim applied for usage of SGLT2 inhibitors in equine animals. The usage of these inhibitors in an animal study allows for progression in the application in humans for more than just diabetes. The National Institute of Biological Science out of Beijing filed a similar patent in September 2015. In January 2016, the Dalian University of Technology filed a patent on the synthetic method of ipragliflozin. There are additional patents for the synthesis of the intermediates leading up to these types of inhibitors.
Bone health refers to the overall condition and strength of the human skeletal system, which is crucial for maintaining mobility, preventing fractures, and supporting overall well-being throughout life. It is influenced by various factors, including genetics, nutrition, physical activity, and hormonal balance. Optimal bone health is characterized by adequate bone mineral density (BMD) and proper bone microarchitecture, which together contribute to bone strength. Osteoporosis, a skeletal disorder characterized by compromised bone strength and increased risk of fractures, is a major concern in bone health, particularly among older adults. Maintaining good bone health involves a combination of adequate calcium and vitamin D intake, regular weight-bearing exercise, and avoiding risk factors such as smoking and excessive alcohol consumption. Recent research has also highlighted the potential role of the gut microbiome in bone health, suggesting a complex interplay between various physiological systems in maintaining skeletal integrity. The human skeletal system is a dynamic structure that consistently works in balance with the rest of the body. In addition to supporting and giving structure to the body, a bone is the major reservoir for many minerals and compounds essential for maintaining a healthy pH balance. The deterioration of the body with age renders the elderly particularly susceptible to and affected by poor bone health.
As noted above, for small deformations, most elastic materials such as springs exhibit linear elasticity and can be described by a linear relation between the stress and strain. This relationship is known as Hooke's law. A geometry-dependent version of the idea was first formulated by Robert Hooke in 1675 as a Latin anagram, "ceiiinosssttuv". He published the answer in 1678: "Ut tensio, sic vis" meaning "As the extension, so the force", a linear relationship commonly referred to as Hooke's law. This law can be stated as a relationship between tensile force F and corresponding extension displacement
Sources: en.wikipedia.org
== Sources == Katz, Arie; Nambi, Sridhar S.; Mather, Kieren; Baron, Alain D.; Follmann, Dean A.; Sullivan, Gail; Quon, Michael J. (2000-07-01). "Quantitative Insulin Sensitivity Check Index: A Simple, Accurate Method for Assessing Insulin Sensitivity In Humans". The Journal of Clinical Endocrinology & Metabolism. 85 (7): 2402–2410. doi:10.1210/jcem.85.7.6661. ISSN 0021-972X. PMID 10902785. Source as above - Katz et al. Also data for unusually healthy individuals derived from those practicing caloric restriction. See CR Society for details.
== Cost == In the United States, intrauterine devices (IUDs) typically cost between $0 and $1,300, with prices covering medical exams, insertion, and follow-up visits. Under the Affordable Care Act, most insurance plans must cover all FDA-approved birth control methods, including IUDs. Coverage for specific brands may vary.
During the 1930s, the rapid industrialisation of the country accelerated the Soviet people's sociological transition from poverty to relative plenty when politically illiterate peasants passed from Tsarist serfdom to self-determination and became politically aware urban citizens. The Marxist–Leninist economic régime modernised Russia from the illiterate, peasant society characteristic of monarchy to the literate, socialist society of educated farmers and industrial workers. Industrialisation led to a massive urbanisation in the country. Unemployment was virtually eliminated in the country during the 1930s. However, this rapid industrialisation also resulted in the Soviet famine of 1930–1933 that killed millions. Social developments in the Soviet Union included the relinquishment of the relaxed social control and allowance of experimentation under Lenin to Stalin's promotion of a rigid and authoritarian society based upon discipline, mixing traditional Russian values with Stalin's interpretation of Marxism. Organised religion was repressed, especially minority religious groups. Education was transformed. Under Lenin, the education system allowed relaxed discipline in schools that became based upon Marxist theory, but Stalin reversed this in 1934 with a conservative approach taken with the reintroduction of formal learning, the use of examinations and grades, the assertion of full authority of the teacher and the introduction of school uniforms.
In biology, homeostasis (in British English also homoeostasis) is the process by which living organisms maintain relatively stable internal physical and chemical conditions despite changes in their internal or external environment. Body temperature, blood glucose, blood pressure, fluid balance, levels of oxygen and carbon dioxide in the blood, pH, and the concentrations of ions such as sodium, potassium, and calcium are all homeostatically regulated variables. These variables are generally maintained within physiological ranges rather than at absolutely constant values; set points for some regulated variables may also change, as occurs with circadian variation in body temperature or during fever. Homeostatic regulation commonly operates through negative feedback. Sensors detect changes in a regulated variable, control mechanisms coordinate an appropriate response, and effectors act to counter the deviation. Regulation can involve the nervous system, endocrine system, and organs: the kidneys, lungs, liver, and pancreas, as well as cellular mechanisms such as the regulation of gene expression. Predictive homeostasis consists of anticipatory responses to expected changes, but these require feedback mechanisms to correct deviations. Together, homeostatic processes maintain conditions in which metabolism and other physiological functions can occur. The concept of regulation of the internal environment was developed in the 19th century by the French physiologist Claude Bernard, and the term homeostasis was coined by the American physiologist Walter Bradford Cannon in 1926.
=== Biotransformation === Caffeate O-methyltransferase is an enzyme responsible for the transformation of caffeic acid into ferulic acid. Caffeic acid and related o-diphenols are rapidly oxidized by o-diphenol oxidases in tissue extracts.
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.
Reversed-phase liquid chromatography is standard for purity, and mass spectrometry is standard for identity. Amino acid analysis is used when quantitative composition matters. No single technique answers every question, so laboratories usually combine two or three.