Everything below concerns freeze-thaw. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-08-30. 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 class. It acts as an agonist at the ghrelin receptor, also called the growth hormone secretagogue receptor type 1a. The compound was designed in the 1990s during a search for agents that release growth hormone with fewer off-target hormonal effects than earlier secretagogues. It appears in the research literature under several sequence-based names. Material supplied for laboratory work is normally a lyophilized solid, and it is not marketed as an approved therapeutic in major jurisdictions.
The molecule contains five residues, including alpha-aminoisobutyric acid, D-2-naphthylalanine, and D-phenylalanine, and it ends in a lysine amide. Non-natural and D-configured residues make the chain less susceptible to common peptidases, which helps explain its resistance to rapid breakdown. Its molecular formula is C38H49N9O5, corresponding to a free-base mass near 711.9 daltons. The C-terminal amide removes a negative charge and is a recurring feature in receptor-active peptides of this family. These structural choices are usually discussed as the basis for its selectivity profile.
Published animal and early human work describes growth hormone release that is separated from comparable rises in adrenocorticotropic hormone and cortisol. Prolactin changes are reported as small in the same studies. Selectivity is attributed to binding at the ghrelin receptor and to the downstream signaling that follows, rather than to differences in how quickly the peptide is cleared. Authors commonly label the compound selective rather than potent, because the same mass produces a smaller growth hormone response than some older secretagogues tested in parallel. Whether that profile holds across species and routes of administration remains an open question.
Compared with older secretagogues such as hexarelin or GHRP-6, ipamorelin shows weaker stimulation of cortisol, prolactin, and appetite in the animal models used for early characterization. Whether that selectivity is preserved across longer human exposures remains an open question, because published clinical data are limited in size and duration. Reported effects on food intake are generally described as modest. The compound is therefore treated in the literature as a relatively selective research tool rather than a fully characterized therapeutic agent.
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.
| Property | Value | Notes |
|---|---|---|
| Molecular formula | C38H49N9O5 | Value for the free base |
| Molar mass | 711.9 g/mol | Calculated from the formula |
| Appearance | White to off-white powder | Typical lyophilized form |
| Mechanism class | Ghrelin receptor agonist | Also described as a secretagogue |
| Half-life | About 2 hours | Reported for human circulation |
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.
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.
Research peptides such as ipamorelin are commonly supplied as lyophilized powder and characterized by analytical certificates. Reversed-phase high-performance liquid chromatography is used to estimate purity by ultraviolet absorbance, while mass spectrometry confirms molecular identity and detects sequence-related impurities. Counterion content, water content, and residual synthesis reagents can affect the reported mass balance. A certificate of analysis may list a purity percentage, but that number depends on the analytical method and the definition of impurity peaks. Independent verification is often recommended because research supply chains vary in quality control practices.
Storage recommendations for ipamorelin usually focus on temperature, moisture, and light. Lyophilized powder is typically held at or below minus twenty degrees Celsius in a desiccated container protected from light. Reconstituted solutions are often aliquoted and stored at minus eighty degrees Celsius to reduce repeated freeze-thaw cycles, which can promote aggregation or degradation. The optimal buffer and pH depend on the specific assay, and no single condition applies to every experimental context. Peptide stability should be assessed with time-point measurements rather than assumed from general handling rules.
In the scientific literature, ipamorelin appears mainly in preclinical studies, receptor binding assays, and reviews of growth hormone secretagogues. Authors often discuss its selectivity profile alongside limitations such as small sample sizes, short study durations, and differences between species. Some papers examine pharmacokinetics and clearance, but human data are limited and not sufficient to define general clinical effects. Regulatory discussion treats the compound as an investigational or research substance rather than an approved therapy in most jurisdictions. Open questions include oral bioavailability, long-term endocrine effects, and whether selectivity observed in animals persists in humans.
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.
Published discussion of this compound is uneven. Some references describe it as a tool for probing growth hormone regulation, while others focus on analytical characterization or on comparisons with related secretagogues. Statements about selectivity, half-life and potency often trace back to a small number of original reports that later authors cite secondhand. Readers evaluating a claim should therefore check whether a figure reflects a direct measurement or a repeated citation, and whether the underlying study was conducted in animals, in isolated cells or in human volunteers.
Kao (known as the "Godfather of Broadband" and "Father of Fiber Optics"). The Fields Medal, one of the most prominent awards a mathematician can receive, has been given to Terence Tao, Shing-Tung Yau, Deng Yu and Turing Award winner Andrew Yao. Tsien Hsue-shen was a prominent aerospace engineer who helped to establish NASA's Jet Propulsion Laboratory. Chen Jingrun was a noted mathematician recognized for his contributions to number theory, where he demonstrated that any sufficiently large even number can be expressed as the sum of two prime numbers or a prime number and a semiprime, a concept now known as Chen's theorem. The 1978 Wolf Prize in Physics inaugural recipient and physicist Chien-Shiung Wu, nicknamed the "First Lady of Physics" contributed to the development of the Manhattan Project and radically altered modern physical theory and changed the conventionally accepted view of the structure of the universe. The geometer Shiing-Shen Chern has been regarded as the "father of modern differential geometry" and has also been recognized as one of the greatest mathematicians of the 20th century. Chern was awarded the 1984 Wolf Prize in mathematics in recognition for his fundamental contributions to the development and growth of differential geometry and topology.
== Early life and education == Todd was born on December 4, 1954, in Washington, D.C., the son of Evetta Lyons Gaither. He grew up in Hartford, Connecticut, attending local schools including Hartford Public High School. He was also an alumnus of the Artists Collective, Inc. Todd attended the University of Connecticut and then went on to study theater at the Tony Award-winning Eugene O'Neill National Actors Theatre Institute, and the Trinity Repertory Company in Providence, Rhode Island. Tony has one living brother and a sister.
Psychiatric disturbances: anxiety CNS reactions: somnolence, malaise, vertigo, paresthesia, headache, apathy Ear problems: hearing loss Heart problems: tachycardia GI reactions: xerostomia, taste disorders, diarrhoea, dyspepsia, upper quadrant pain, lip paresthesia, nausea, vomiting, constipation, excessive thirst Hepatic and bile ducts reactions: hepatic insufficiency, hepatitis, increased liver enzymes Skin and soft tissue reactions: rash, pruritus, urticaria, flushing, blistering, lumps, exudation, erythema multiforme Renal reactions: urinary retention Reproductive system reactions: dysmenorrhoea, mastitis, gynecomastia in males, breast pain
== Foundation == Galway University Foundation (GUF) was established in 1998 with the intention of generating financial support for the university from private individuals and institutions. It nurtures relationships with donors for whom the university's approach to education appeals. The Foundation has many 'Priority Projects' in development.
The ABCR -/- knockout mouse has delayed dark adaptation but normal final rod threshold relative to controls. Bleaching the retina with strong light leads to formation of toxic cationic bis-pyridinium salt, N-retinylidene-N-retinyl-ethanolamine (A2E), which causes dry and wet age-related macular degeneration. From this experiment, it was concluded that ABCR has a significant role in preventing formation of A2E in extracellular photoreceptor surfaces during bleach recovery.
Sources: en.wikipedia.org
== Commercialization == ChromaDex (now Niagen Bioscience) licensed patents for nicotinamide riboside from Dartmouth College, Cornell University, and Washington University in St. Louis in July 2012. The company developed a commercial production process for nicotinamide riboside chloride, trademarking the active ingredient as Niagen. ChromaDex has continued to expand using the brand name Tru Niagen globally while also supplying Niagen as an ingredient to other manufacturers. ChromaDex was in a patent dispute with Elysium Health over the rights to nicotinamide riboside supplements between 2016 and 2023. ChromaDex holds multiple patents related to nicotinamide riboside, including manufacturing methods, compositions, and uses. As of 2023, ChromaDex's patent portfolio for nicotinamide riboside includes 50+ granted patents and numerous pending patent applications worldwide. As of March 19, 2025, ChromaDex was renamed Niagen Bioscience, and now trades under the Ticker Symbol 'NAGE'.
* UAG is normally the amber stop codon, but in organisms containing the biological machinery encoded by the pylTSBCD cluster of genes the amino acid pyrrolysine will be incorporated. ** UGA is normally the opal (or umber) stop codon, but encodes selenocysteine if a SECIS element is present. † The stop codon is not an amino acid, but is included for completeness. †† UAG and UGA do not always act as stop codons (see above). ‡ An essential amino acid cannot be synthesized in humans and must, therefore, be supplied in the diet. Conditionally essential amino acids are not normally required in the diet, but must be supplied exogenously to specific populations that do not synthesize it in adequate amounts. & Occurrence of amino acids is based on 135 Archaea, 3775 Bacteria, 614 Eukaryota proteomes and human proteome (21 006 proteins) respectively.
=== Sexual deviance === CPA is used as an antiandrogen and form of chemical castration in the treatment of paraphilias and hypersexuality in men. It is used to treat sex offenders. The medication is approved in more than 20 countries for this indication and is predominantly employed in Canada, Europe, and the Middle East. CPA works by decreasing sex drive and sexual arousal and producing sexual dysfunction. CPA can also be used to reduce sex drive in individuals with inappropriate sexual behaviors, such as people with intellectual disability and dementia. The medication is also used to reduce sexual behavior diagnosed as self-harmful, such as masochism. CPA has comparable effectiveness to medroxyprogesterone acetate in suppressing sexual urges and function but appears to be less effective than GnRH modulators like leuprorelin and has more side effects. High-dose CPA significantly decreases sexual fantasies and sexual activity in 80 to 90% of men with paraphilias. In addition, it has been found to decrease the rate of reoffending in sex offenders from 85% to 6%, with most of the reoffenses being committed by individuals who did not follow their CPA treatment prescription. It has been reported that in 80% of cases, 100 mg/day CPA is adequate to achieve the desired reduction of sexuality, whereas in the remaining 20% of cases, 200 mg/day is sufficient. When only a partial reduction in sexuality is desired, 50 mg/day CPA can be useful.
== Early life and education == Born in New York City in 1940, Lewis B. Sheiner received his Bachelor of Arts degree with Honors in Chemistry from Cornell University in 1960 and earned his Doctor of Medicine (M.D.) from the Albert Einstein College of Medicine in 1964.
Sources: en.wikipedia.org
=== Legal === This technique is also used for detection of illicit drugs in various samples. The most common method of drug detection has been an immunoassay. This method is much more convenient. However, convenience comes at the cost of specificity and coverage of a wide range of drugs, therefore, HPLC has been used as well as an alternative method. As HPLC is a method of determining (and possibly increasing) purity, using HPLC alone in evaluating concentrations of drugs was somewhat insufficient. Therefore, HPLC in this context is often performed in conjunction with mass spectrometry. Using liquid chromatography-mass spectrometry (LC-MS) instead of gas chromatography-mass spectrometry (GC-MS) circumvents the necessity for derivitizing with acetylating or alkylation agents, which can be a burdensome extra step. LC-MS has been used to detect a variety of agents like doping agents, drug metabolites, glucuronide conjugates, amphetamines, opioids, cocaine, BZDs, ketamine, LSD, cannabis, and pesticides. Performing HPLC in conjunction with mass spectrometry reduces the absolute need for standardizing HPLC experimental runs.
=== Antimicrobial activity === In plant Oldenlandia affinis it generates antimicrobial cyclic peptides which are important for defence against pathogens in plants. The herb has been used in native African medicine to accelerate childbirth.
{\displaystyle {\begin{aligned}\nabla \cdot {\boldsymbol {\sigma }}(\mathbf {u} ,p)&=\nabla \cdot \left(-p\mathbf {I} +2\mu {\boldsymbol {\varepsilon }}(\mathbf {u} )\right)\\&=-\nabla p+2\mu \nabla \cdot {\boldsymbol {\varepsilon }}(\mathbf {u} )\\&=-\nabla p+2\mu \nabla \cdot \left[{\tfrac {1}{2}}\left(\left(\nabla \mathbf {u} \right)+\left(\nabla \mathbf {u} \right)^{\mathsf {T}}\right)\right]\\&=-\nabla p+\mu \left(\Delta \mathbf {u} +\nabla \cdot \left(\nabla \mathbf {u} \right)^{\mathsf {T}}\right)\\&=-\nabla p+\mu {\bigl (}\Delta \mathbf {u} +\nabla \underbrace {(\nabla \cdot \mathbf {u} )} _{=0}{\bigr )}=-\nabla p+\mu \,\Delta \mathbf {u} .\end{aligned}}}
Sources: en.wikipedia.org
It has not been approved as a therapeutic by major regulators, and the human trial record is small and dated. Material available today is mostly sold as a research chemical for laboratory use. Approval and restriction status varies by country.
It binds the ghrelin receptor, known as the growth hormone secretagogue receptor type 1a. Activation of that receptor triggers signaling that leads to growth hormone release. Selectivity for growth hormone over cortisol and prolactin is the property most often cited for this compound.
Published estimates place the circulating half-life at roughly two hours in humans. Clearance involves peptidase activity and renal handling. Because the peptide is short-lived, release patterns after administration are usually described as pulsatile rather than sustained.
It is a synthetic pentapeptide in the growth hormone secretagogue family. The chain contains five residues, two of which are non-natural amino acids.