Compound monograph
Examorelin (Hexarelin)
Examorelin, widely supplied as hexarelin, is a synthetic hexapeptide growth hormone secretagogue carrying a 2-methylated D-tryptophan.
01
Identity & nomenclature
Examorelin, widely supplied as hexarelin, is a synthetic hexapeptide growth hormone secretagogue carrying a 2-methylated D-tryptophan.
Examorelin and hexarelin are one substance under two names, not two entries. Its relationship to GHRP-6 is a single methyl group — a net CH2, 14.0157 Da — but 'methylated GHRP-6' is insufficient identity information unless the methyl position is retained.
Declared aliases and development codes: Hexarelin, EP-23905, MF-6003.
02
Molecular properties
| Molecular formula | C47H58N12O6 |
|---|---|
| Molecular mass | 887.06 Da |
| CAS Registry Number | 140703-51-1 |
| PubChem CID | 6918297 |
| UNII | 09QF37C617 |
| Three-letter sequence | His–2-Me-D-Trp–Ala–Trp–D-Phe–Lys–NH2 |
Position 2 carries a methyl group at INDOLE POSITION 2 of D-tryptophan. It is not an N-methyl and not an alpha-methyl substitution; those are different molecules with the same formula. No one-letter string is published here.
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Structural characteristics
This is the compound that refutes the assumption that synthetic secretagogues are interchangeable or GHSR-exclusive. Beyond ghrelin-receptor agonism, exact-compound work identifies CD36 as a binding target, maps the binding site to a defined fragment of the CD36 sequence, and reports that a cardiovascular response to hexarelin is absent in CD36-null animals. CD36 is a scavenger receptor, not a GHSR subtype. The relative contribution of the two targets belongs to the preparation tested, not to the compound in general.
- 2-methyl-D-tryptophan at position 2
- D-Phe5
Terminal features: Free N-terminus, C-terminal amide at Lys6.
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Molecular targets & mechanisms
Growth hormone secretagogue receptor
GHS-R1a · Ghrelin receptor · GHSR
A G-protein-coupled receptor distinct from the GHRH receptor. Antagonist profiling reported that ipamorelin releases growth hormone through a GHRP-like receptor rather than through the GHRH receptor, establishing the two pathways as separate.
CD36 scavenger receptor
CD36 · FAT · SR-B2
A multifunctional scavenger receptor, distinct from the growth hormone secretagogue receptor, reported as a binding target for certain synthetic secretagogue peptides. It is recorded separately here precisely because collapsing it into the ghrelin-receptor mechanism would erase the finding that these compounds are not pharmacologically interchangeable.
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Analytical considerations
The mass difference from GHRP-6 is readily measurable, but equal-mass methyl positional isomers and D/L variants are not resolved by mass alone; establishing the indole-2 position needs NMR or an authenticated orthogonal comparison. A positive GHSR assay is unusually weak evidence here, because the compounds it would distinguish this from were selected for sharing that activity.
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Verified bibliography
- CD36 mediates the cardiovascular action of growth hormone-releasing peptides in the heart.current
Bodart V, Febbraio M, Demers A, McNicoll N, Pohankova P, Perreault A, Sejlitz T, Escher E, Silverstein RL, Lamontagne D, Ong H
Circulation research · 2002-05-03 · Journal Article
- Identification of the growth hormone-releasing peptide binding site in CD36: a photoaffinity cross-linking study.current
Demers A, McNicoll N, Febbraio M, Servant M, Marleau S, Silverstein R, Ong H
The Biochemical journal · 2004-09-01 · Journal Article
- Determination of growth hormone releasing peptides (GHRP) and their major metabolites in human urine for doping controls by means of liquid chromatography mass spectrometry.current
Thomas A, Höppner S, Geyer H, Schänzer W, Petrou M, Kwiatkowska D, Pokrywka A, Thevis M
Analytical and bioanalytical chemistry · 2011-02-06 · Journal Article
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Methodology & citation verification
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