Compound monograph
Anamorelin
Anamorelin is a nonpeptide small-molecule agonist at the ghrelin receptor, structurally unrelated to the peptide secretagogues that share its target.
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Identity & nomenclature
Anamorelin is a nonpeptide small-molecule agonist at the ghrelin receptor, structurally unrelated to the peptide secretagogues that share its target.
The CAS recorded here is the parent free base. The hydrochloride requires separate salt accounting; chloride is not part of this formula. Describing anamorelin as a ghrelin mimetic says nothing about sequence homology with ghrelin, of which it has none.
Declared aliases and development codes: ONO-7643, RC-1291, ST-1291.
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Molecular properties
| Molecular formula | C31H42N6O3 |
|---|---|
| Molecular mass | 546.72 Da |
| CAS Registry Number | 249921-19-5 |
| PubChem CID | 9828911 |
| UNII | DD5RBA1NKF |
Not a conventional peptide and no sequence string is published here. A 3R-substituted piperidine-3-carbohydrazide bearing a benzyl group and an N,N',N'-trimethylhydrazide, acylated through a D-Trp-derived 2R centre and an Aib-derived aminoacyl unit. No lipid conjugation and no macrocycle.
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Structural characteristics
Receptor-bound structural work reports anamorelin behaving as a superagonist in the system studied, and separate structures place it alongside macimorelin in the same bifurcated binding pocket. A comparison across two assay formats found it a full agonist in both. 'Full agonist' versus 'superagonist' is a question of assay context, not two chemical identities; a single assay-independent intrinsic-activity or signalling-bias label is not established.
- trimethylhydrazide
- 2R and 3R stereocentres
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Molecular targets & mechanisms
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Analytical considerations
Matching molecular mass excludes neither epimers nor connectivity isomers, and a receptor activation assay cannot distinguish anamorelin from macimorelin or any other active ligand. NMR should establish the piperidine, hydrazide and aminoacyl connectivity, with a chiral method for the 2R and 3R centres. For hydrochloride material, quantify chloride independently rather than inferring it from the parent ion.
Disagreements and mix-ups
Points where sources disagree about this compound's identity, or where a name or form is easily confused with another, as noted in this record. The discrepancy register quotes the passage for each one.
Often mixed up · Salt or form
Anamorelin free base vs hydrochloride
What the studies reported
Each finding describes one cited study in its stated model. These observations are specific to that study and do not establish effects in other settings.
Cell and tissue studies
Gq-coupled GHSR cryo-electron microscopy preparation
Using a Gq-coupled GHSR cryo-electron microscopy preparation, the study reported the anamorelin-bound structure at 2.52 Å resolution.
Reference [1]Anamorelin-bound Gq-coupled GHSR structural preparation
Using an anamorelin-bound Gq-coupled GHSR structural preparation, the study identified a bifurcated ligand-binding pocket divided by the conserved E1243.33-R2836.55 salt bridge.
Reference [1]Ghrelin receptor-miniGq structural preparation
Using a ghrelin receptor-miniGq structural preparation, the study reported an anamorelin-bound receptor structure.
Reference [2]GHSR dynamic mass redistribution and calcium mobilization assays
Using GHSR dynamic mass redistribution and calcium mobilization assays, the study reported anamorelin as a potent full agonist.
Reference [3]
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Verified bibliography
Cited studies by type
The 3 papers this record cites, counted by the kind of work each reports. A count is the size of this record's selection, not of the research that exists, and says nothing about results, safety, effectiveness or approval.
A paper can report more than one kind of work. Each count opens those papers in the bibliography. Compare every record on the Evidence Map.
Reference 1
Molecular recognition of two approved drugs Macimorelin and Anamorelin by the growth hormone secretagogue receptor.Wang RL, Sun J, Liu H, Guo SM, Zhang Y, Hu W, Wang J, Liu H, Zhuang YW, Jiang Y, Xie X, Xu HE, Wang Y
Acta pharmacologica Sinica · 2025-06-20 · Journal Article
currentReference 2
The structure and function of the ghrelin receptor coding for drug actions.Shiimura Y, Im D, Tany R, Asada H, Kise R, Kurumiya E, Wakasugi-Masuho H, Yasuda S, Matsui K, Kishikawa JI, Kato T, Murata T, Kojima M, Iwata S, Masuho I
Nature structural & molecular biology · 2025-01-20 · Journal Article
currentReference 3
In vitro pharmacological characterization of growth hormone secretagogue receptor ligands using the dynamic mass redistribution and calcium mobilization assays.Sturaro C, Ruzza C, Ferrari F, Pola P, Argentieri M, Frezza A, Marzola E, Bettegazzi B, Cattaneo S, Pietra C, Malfacini D, Calò G
European journal of pharmacology · 2024-08-10 · Journal Article
current
Study models of these references
What kind of experiment each cited paper reports, taken from its abstract unless marked. Not a summary of results.
| Reference | Study models |
|---|---|
| Wang RL et al. 2025 | Study models reported: in vitro · from the abstract |
| Shiimura Y et al. 2025 | Study models reported: in vitro · from the abstract |
| Sturaro C et al. 2024 | Study models reported: in vitro · from the abstract |
Record history
Published 2026-09-13.
No changes to this record's content have been recorded since publication.
Each entry names the parts of this record that changed on that date. Changes to links between records and to catalogue links are not listed. This history covers the tracked record fields; study findings are not listed here.
Cite this record: Purely Peptides Research Library. Anamorelin. Published 2026-09-13. https://purelypeptides.org/research/compounds/anamorelin/
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Methodology & citation verification
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