This is a working overview of pentapeptide, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2026-08-01 and is reviewed periodically as new material appears.
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.
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.
Human data remain limited and come mainly from small, short-term studies conducted decades ago. The peptide has not received approval as a medicine from major regulators, so current availability is largely as a research chemical. Reported effects on growth hormone pulsatility, appetite, and body composition should be read as preliminary, since few independent groups have replicated the original findings. Analytical characterization of research-grade material varies between suppliers, which complicates comparison across studies. Regulatory status also differs by country, and some jurisdictions classify it as a prescription-only or otherwise restricted item.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized solid as supplied |
| Solubility | Freely soluble in water and polar solvents | Dissolution may require brief mixing |
| Typical storage temperature | Minus 20 degrees Celsius or below | Dry, desiccated, protected from light |
| Common analytical method | Reversed-phase HPLC with mass spectrometry | Purity plus identity confirmation |
| Common synonyms | Ipamorelin acetate, NNC 26-0161 | Research code used in early literature |
在机制层面，ipamorelin 与生长激素促分泌受体 1a 型结合，该受体也介导胃饥饿素的多种效应。受体激活后，细胞内信号促进生长激素从垂体前叶释放。由于对促肾上腺皮质激素和皮质醇的刺激较弱，它被视为选择性较高的促分泌剂。这种选择性在动物模型和少量人体研究中被观察到，但人体数据仍然有限。
现有文献多来自小规模、短期的研究，涉及生长激素缺乏、术后肠麻痹等方向。长期使用是否导致受体脱敏，以及重复给药后效应是否衰减，仍属开放问题。不同研究之间的剂量、给药途径和受试者特征差异较大，因此结论外推需谨慎。关于临床获益的确切证据尚不充分，需要更大规模的对照试验来澄清。
Ipamorelin 是一种合成五肽，在 20 世纪 90 年代被报道为生长激素促分泌剂。其结构基于胃饥饿素受体激动剂的设计思路，但并非天然激素。早期药理学研究显示，它可刺激垂体释放生长激素，而对应激激素轴的影响相对较小。该化合物常被用作研究生长激素调节通路的工具分子。
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.
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.
Glucagon receptor Glucagon-like peptide 1 receptor Glucagon-like peptide 2 receptor Gastric inhibitory polypeptide receptor The first three receptors bind closely related peptide hormones (glucagon, glucagon-like peptide-1, glucagon-like peptide-2) derived from the proglucagon polypeptide. The last receptor binds gastric inhibitory polypeptide.
A rheumatologist is a physician who specializes in the field of medical sub-specialty called rheumatology. A rheumatologist holds a board certification after specialized training. In the United States, training in this field requires four years of undergraduate school, four years of medical school, and then three years of residency, followed by two or three years of additional Fellowship training. The requirements may vary in other countries. Rheumatologists are internists who are qualified by additional postgraduate training and experience in the diagnosis and treatment of arthritis and other diseases of the joints, muscles, and bones. Many rheumatologists also conduct research to determine the cause and better treatments for these disabling and sometimes fatal diseases. Treatment modalities are based on scientific research, currently, the practice of rheumatology is largely evidence-based. Rheumatologists treat arthritis, autoimmune diseases, pain disorders affecting joints, and osteoporosis. There are more than 200 types of these diseases, including rheumatoid arthritis, osteoarthritis, gout, lupus, back pain, osteoporosis, and tendinitis. Some of these are very serious diseases that can be difficult to diagnose and treat. They treat soft tissue problems related to the musculoskeletal system and sports-related soft tissue disorders. Pediatric rheumatologist: A pediatric rheumatologist is a pediatrician who specializes in the treatment of children with rheumatic disease.
Due to the growing concerns of the high cost, health consequences, and illegal nature of some steroids, many organizations have formed in response and have deemed themselves "natural" bodybuilding competitions. In addition to the concerns noted, many promoters of bodybuilding have sought to shed the "freakish" perception that the general public has of bodybuilding and have successfully introduced a more mainstream audience to the sport of bodybuilding by including competitors whose physiques appear much more attainable and realistic. In natural contests, the testing protocol ranges among organizations from lie detectors to urinalysis. Penalties vary between organisations, from suspensions to strict bans from competition. Natural organizations also have their own list of banned substances and it is important to refer to each organization's website for more information about which substances are banned from competition. There are many natural bodybuilding organizations; some of the larger ones include: MuscleMania, Ultimate Fitness Events (UFE), INBF/WNBF, and INBA/PNBA. These organizations either have an American or worldwide presence and are not limited to the country in which they are headquartered.
Sources: en.wikipedia.org
A story with Frazier Tharpe for GQ, published on June 2, 2025, started by stating that Clipse were unimpressed with the current state of mainstream hip-hop. The brothers gave Stove God Cooks and Future as exceptions. Pusha T lamented the feelings of loneliness and need to play "industry games" that came with his solo career, revealed that he was already becoming disillusioned with his former boss West during the 2019 recording sessions for Jesus Is King, and criticized West for his perceived character flaws. He also denied being a bad friend to West. The story of Clipse's dispute with Def Jam Recordings was told for the first time in this interview. Also included were comments about Drake suing Universal Music Group ("The suing thing is bigger than some rap shit. I just don't rate you.") and more details about the album: tracks "Mike Tyson", "POV", "F.I.C.O.", and features from Stove God Cooks and Lamar. After the release of "So Be It", GQ published a follow-up article (with unused excerpts from the interview) in which the song was discussed, including lyrics from Pusha T which diss Travis Scott. Another interview with Andre Gee for Rolling Stone was published on June 9. Clipse elaborated on their distribution deal with Roc Nation and announced a nationwide United States tour, planned to take place across twenty-five shows from August 3 to September 10.
== Biosynthesis == The biosynthesis of thujone is similar to the synthesis of other monoterpenes and begins with the formation of geranyl diphosphate (GPP) from dimethylallyl pyrophosphate (DMAPP) and isopentenyl diphosphate (IPP), catalyzed by the enzyme geranyl diphosphate synthase. Quantitative 13C NMR spectroscopic analysis has demonstrated that the isoprene units used to form thujone in plants are derived from the methylerythritol phosphate pathway (MEP). The reactions that generate the thujone skeleton in sabinene from GPP are mediated by the enzyme sabinene synthase which has GPP as its substrate. GPP (1) first isomerizes to linally diphosphate (LPP) (2) and neryl diphosphate (NPP) (3). LPP preferentially forms a delocalized allylic cation-diphosphate (4). The ion-pair intermediate then cyclizes in an electrophilic addition to yield the α-terpinyl tertiary cation (5).
==== In aqueous solution ==== Most neptunium coordination complexes known in solution involve the element in the +4, +5, and +6 oxidation states: only a few studies have been done on neptunium(III) and (VII) coordination complexes. For the former, NpX2+ and NpX+2 (X = Cl, Br) were obtained in 1966 in concentrated LiCl and LiBr solutions, respectively: for the latter, 1970 experiments discovered that the NpO3+2 ion could form sulfate complexes in acidic solutions, such as NpO2SO+4 and NpO2(SO4)−2; these were found to have higher stability constants than the neptunyl ion (NpO2+2). A great many complexes for the other neptunium oxidation states are known: the inorganic ligands involved are the halides, iodate, azide, nitride, nitrate, thiocyanate, sulfate, carbonate, chromate, and phosphate. Many organic ligands are known to be able to be used in neptunium coordination complexes: they include acetate, propionate, glycolate, lactate, oxalate, malonate, phthalate, mellitate, and citrate. Analogously to its neighbours, uranium and plutonium, the order of the neptunium ions in terms of complex formation ability is Np4+ > NpO2+2 ≥ Np3+ > NpO+2. (The relative order of the middle two neptunium ions depends on the ligands and solvents used.) The stability sequence for Np(IV), Np(V), and Np(VI) complexes with monovalent inorganic ligands is F− > H2PO−4 > SCN− > NO−3 > Cl− > ClO−4; the order for divalent inorganic ligands is CO2−3 > HPO2−4 > SO2−4. These follow the strengths of the corresponding acids. The divalent ligands are more strongly complexing than the monovalent ones.
== Global production == In 2012, 158,000 kilograms of thebaine were produced. In 2013, Australia was the main producer of poppy straw rich in thebaine, followed by Spain and then France. By 2017, worldwide thebaine production dropped to 142,400 kg. Together, those three countries accounted for about 99 per cent of global production of such poppy straw. The seed capsules of Papaver bracteatum are the primary source of thebaine, with the stem additionally yielding a significant amount. Although thebaine is not used therapeutically, it is a starting material for industrial productions of pharmaceutical drugs including hydrocodone, hydromorphone, oxycodone, oxymorphone, nalbuphine, naloxone, naltrexone, buprenorphine, butorphanol and etorphine.
Sources: en.wikipedia.org
Eoox = −Eored The oxidation potential is a measure of the tendency of the reducing agent to be oxidized but does not represent the physical potential at an electrode. With this notation, the cell voltage equation is written with a plus sign
=== Cuba === In December 2021, the new Cuban ambassador to Peru, Carlos Rafael Zamora Rodríguez, alias "El Gallo", arrived in Peru, linked to the Cuban Directorate of Intelligence. It was reported that he had previously served as ambassador to Bolivia in 2019 during the government of Evo Morales. Upon his arrival, Zamora presented his credentials to Castillo, announcing that efforts were being made to strengthen diplomatic relations between both nations.
== Effects on animals == In mice and rats: it has been shown that Sarafotoxin has three independent effects in both mice and rats hearts, a rapid and marked vasoconstriction of the coronary vessels, a severe atrioventricular block, and a slower but very strong positive inotropic effect. It also binds with a high affinity to the membranes of atrial and brain to induce hydrolysis of phosphoinositides in these tissues. In a study investigating the impact of sarafotoxin-b on respiratory properties, it was found that there was a marked increase in the airway resistance. This was likely caused by bronchoconstriction. Bronchoconstriction occurred due to a constriction of smooth muscle and airway wall thickening due to peribronchial edema. This peribronchial edema is likely caused by impairment of left ventricular relaxation, elevating microvascular hydrostatic pressure. Proving this theory of edema, during investigation, abundant and frothy fluid was found in tracheal cannulas after sarafotoxin injection. The same study also found marked disturbances in gas exchange and acid-base equilibrium after injection with the toxin. Acute hypoxemia was due to bronchoconstriction and pulmonary edema. Hypoxemia was associated with metabolic acidosis and the increase in the anion gap may have been due to increased blood lactates induced by hypoxia. There was also a measured decrease in PCO₂, which may be explained by a decreased cardiac output, decreasing carbon dioxide transport to the lung.
The dehydrogenation of 17α-hydroxyprogesterone acetate [302-23-8] (1) with chloranil (tetrachloro-p-benzoquinone) gives a compound that has been called melengestrol acetate [425-51-4] (2). Dehydrogenation with selenium dioxide gives 17-acetoxy-1,4,6-pregnatriene-3,20-dione [2668-75-9] (3). Reacting this with diazomethane results in a 1,3-dipolar addition reaction at C1–C2 of the double bond of the steroid system, which forms a derivative of dihydropyrazole, CID:134990386 (4). This compound cleaves when reacted with perchloric acid, releasing nitrogen molecules and forming a cyclopropane derivative, 6-deschloro cyproterone acetate [2701-50-0] (5). Selective oxidation of the C6=C7 olefin with benzoyl peroxide gives the epoxide, i.e. 6-deschloro-6,7-epoxy cyproterone [15423-97-9] (6). The penultimate step involves a reaction with hydrochloric acid in acetic acid, resulting in the formation of chlorine and its subsequent dehydration, and a simultaneous opening of the cyclopropane ring giving 1α-(chloromethyl) chlormadinone acetate [17183-98-1] (7). The heating of this in collidine reforms the cyclopropane ring, completing the synthesis of CPA (8).
== Further reading == Sitruk-Ware R, Bricaire C, De Lignieres B, Yaneva H, Mauvais-Jarvis P (October 1987). "Oral micronized progesterone. Bioavailability pharmacokinetics, pharmacological and therapeutic implications--a review". Contraception. 36 (4): 373–402. doi:10.1016/0010-7824(87)90088-6. PMID 3327648. Simon JA (December 1995). "Micronized progesterone: vaginal and oral uses". Clinical Obstetrics and Gynecology. 38 (4): 902–14. doi:10.1097/00003081-199538040-00024. PMID 8616985. Ruan X, Mueck AO (November 2014). "Systemic progesterone therapy--oral, vaginal, injections and even transdermal?". Maturitas. 79 (3): 248–55. doi:10.1016/j.maturitas.2014.07.009. PMID 25113944.
Sources: en.wikipedia.org
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.
The peptide contains aromatic and imidazole groups that absorb ultraviolet light and can participate in photo-induced reactions. Those reactions can alter the molecule or generate new species. Amber glass or opaque packaging reduces the exposure.
Long-term stability data across many temperature and humidity conditions are limited. Most guidance is extrapolated from short studies on related peptides. The effect of repeated handling on a specific lot is generally not characterized.
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.