Hexarelin is a coined name, not a chemical name. Here we document Hexarelin as an identity reference: what the sequence is, which residues are non-natural, what mass to expect, how it behaves under reverse-phase HPLC, and how a buyer can confirm that the material in a vial is what the label says. What Hexarelin does is outside its scope, and it contains no guidance on preparation, handling or dosing.
The sequence behind Hexarelin
Hexarelin is the synthetic hexapeptide:
His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2
Six residues, a C-terminal amide, and two features that set it apart from an ordinary linear peptide. The residue in position 2 is D-2-methyl-tryptophan: a tryptophan with the D configuration at its alpha carbon and a methyl group on carbon 2 of the indole ring. The residue in position 5 is D-phenylalanine. The remaining residues — histidine, alanine, tryptophan and lysine — are standard L-amino acids.
Its molecular formula is C47H58N12O6 and its average molecular mass is approximately 887.0 g/mol. The compound has also been catalogued under the name examorelin and under development codes, but the sequence above is the identifier that matters.
Why Hexarelin is a designation rather than an identifier
Hexarelin belongs to a family of short synthetic peptides built around the same core. Its closest relative is GHRP-6, His-D-Trp-Ala-Trp-D-Phe-Lys-NH2. The two sequences are identical except for the methyl group on the indole ring of the position-2 residue. That single methyl adds about 14 daltons of mass and a little extra hydrophobicity — small differences that a trade name does not reveal and a careless label can easily blur. Other members of the wider family, such as ipamorelin, share some residues and design logic but differ in length and composition.
The practical consequence is the same one that runs through this series. Two products labelled “Hexarelin” are only the same compound if they share the same sequence, the same stereochemistry at positions 2 and 5, and the same modification on the tryptophan ring. The sequence printed by a supplier, and the mass on its published analysis, are what let you check that.
How hexarelin behaves on reverse-phase HPLC
Hexarelin is small but not especially polar. Two indole side chains and a phenyl ring give it a substantial hydrophobic surface, balanced by the basic histidine, the basic lysine side chain and a free N-terminal amine. On a C18 column with a water/acetonitrile gradient and trifluoroacetic acid as the ion-pairing agent it retains well and elutes clear of the solvent front, noticeably later than polar short peptides of similar length.
Detection is straightforward. The two tryptophan-derived residues absorb strongly near 280 nm, so hexarelin can be followed at 280 nm as well as on the peptide bond at around 214 nm. Purity is normally reported at 214 nm, because every peptide-bonded species absorbs there; the 280 nm trace is a helpful cross-check but will under-report impurities that have lost an aromatic residue.
Two analytical details are specific to this compound. First, the D-residues mean that a diastereomer — the same sequence with the wrong configuration at one position — is a plausible synthesis impurity. It has the same mass as the target, so mass spectrometry alone will not flag it; only chromatographic separation can. Second, a batch made with unmethylated D-tryptophan in position 2 would be a different compound, and one about 14 daltons lighter. Our guide to peptide synthesis impurities covers deletion sequences, diastereomers and the other species that typically sit near the main peak.
What an analysis for hexarelin should show
A useful certificate reports the column chemistry and dimensions, the mobile phase and gradient, the detection wavelength, the retention time, the integrated peak area with the integration window visible, and a mass confirmation. For hexarelin the mass confirmation should land at approximately 887 for the neutral peptide, or at the corresponding protonated ions; basic peptides of this kind commonly appear in electrospray spectra as both singly and doubly charged species. Our article on mass spectrometry and peptide identity explains how to read those charge states.
The certificate for Hexarelin ought to list net peptide content independently of purity and say which counter-ion is present. With a free N-terminus, a histidine and a lysine, hexarelin has several sites that can carry a counter-ion, so a trifluoroacetate or acetate salt contributes a meaningful share of the powder’s weight. A high HPLC purity describes how clean the peptide fraction is; it does not describe how much of the powder in the vial is peptide.
Confirming identity independently
Search the Hexarelin structure rather than its designation. Public chemical databases index hexarelin by formula, by systematic name and by its synonyms, and a search on C47H58N12O6 or on the full sequence including the D-2-methyl-Trp residue will show whether the pairing of name and structure a vendor uses matches the pairing used elsewhere. Then compare the observed mass on the published analysis with approximately 887.0: a result near 873 suggests the unmethylated relative rather than hexarelin.
How hexarelin is supplied here
Hexarelin 2mg is supplied as a lyophilised powder in a sealed vial. Hexarelin is analyzed by an independent laboratory using reverse-phase HPLC, and that result is published on its product page. The product listing for Hexarelin gives the vial size together with the published HPLC purity. No batch or lot code appears on a Hexarelin vial; the crimp and cap color identify which published analysis it belongs to.
Frequently asked questions
What is the amino acid sequence of hexarelin?
His-D-2-methyl-Trp-Ala-Trp-D-Phe-Lys-NH2: a hexapeptide with a C-terminal amide, a D-2-methyl-tryptophan in position 2 and a D-phenylalanine in position 5.
Is hexarelin the same as GHRP-6?
No. The sequences are identical apart from the methyl group on the indole ring of the position-2 residue, which hexarelin carries and GHRP-6 does not. They differ in mass by about 14 daltons and separate on a reverse-phase column, and a certificate for one is not evidence about the other.
What molecular weight should I expect for Hexarelin?
Approximately 887.0 g/mol for the free base, formula C47H58N12O6. A declared counter-ion is needed because a Hexarelin salt weighs more than the free peptide.
Can mass spectrometry alone confirm the D-residues?
No. A diastereomer has the same mass as the correct compound. Stereochemistry is confirmed by chromatographic separation against a reference or by dedicated chiral analysis, not by the mass figure.
Research use only. All products supplied by Battle Born Peptides are laboratory reference materials for in-vitro research and analytical use by qualified professionals. They are not drugs, foods, dietary supplements, cosmetics or medical devices; they are not approved by the FDA or any other regulator for use in humans or animals; and they are not intended to diagnose, treat, cure, mitigate or prevent any disease, or to affect the structure or any function of the body of humans or animals. Nothing in this article is preparation, handling or dosing guidance. See our full research-use terms.