Peptide reference · Synthetic hexapeptide (contains non-standard residues)
Hexarelin COA check: molecular weight, formula and what to look for
Use these reference values to check the identity result on a Hexarelin Certificate of Analysis. The theoretical average molecular weight of Hexarelin is 887.04 Da and the monoisotopic mass is 886.460 Da.
Check a Hexarelin COA nowHexarelin reference data
| Name | Hexarelin |
|---|---|
| Also known as | Examorelin |
| Type | Synthetic hexapeptide (contains non-standard residues) |
| Molecular formula | C47H58N12O6 |
| Average molecular weight | 887.04 g/mol (Da) |
| Monoisotopic mass | 886.4602 Da |
| Residues | 6 |
| Sequence | His-D-2-Me-Trp-Ala-Trp-D-Phe-Lys-NH₂ |
| Reference source | PubChem CID 6918297 (formula and mass cross-checked) |
Expected mass spectrometry ions
A Hexarelin COA may list one of these m/z values instead of the neutral mass. That is still consistent with Hexarelin. How charge states work.
| Ion | m/z (monoisotopic) | m/z (average) |
|---|---|---|
| [M+H]+ | 887.47 | 888.05 |
| [M+2H]2+ | 444.24 | 444.53 |
| [M+3H]3+ | 296.49 | 296.69 |
What else can show up on a Hexarelin COA
Masses calculated from Hexarelin's formula and sequence for the adducts, degradation products and synthesis impurities a lab report can show. A match tells you what the extra peak probably is.
| Signal | Value | What it means |
|---|---|---|
| Na adduct, deconvoluted (M + 21.98) | 908.44 Da | Sodium adduct: an MS artifact, not a separate impurity. The [M+Na]+ ion itself is at M + 22.99 |
| K adduct, deconvoluted (M + 37.96) | 924.42 Da | Potassium adduct: an MS artifact. The [M+K]+ ion itself is at M + 38.96 |
| TFA adduct (M + 113.99) | 1,000.45 Da | Trifluoroacetic acid from purification seen as an adduct; residual TFA salt is real vial content |
| M + 16 (oxidation) | 902.46 Da | Oxidation of Trp |
| M + 0.98 (free acid) | 887.44 Da | C-terminal amide hydrolysed or free-acid synthesis error |
Deletion sequences (6): one residue missing
| Signal | Value | What it means |
|---|---|---|
| des-His (M − 137.06) | 749.40 Da | Deletion sequence missing one His |
| des-2-Me-Trp (M − 200.09) | 686.37 Da | Deletion sequence missing one 2-Me-Trp |
| des-Ala (M − 71.04) | 815.42 Da | Deletion sequence missing one Ala |
| des-Trp (M − 186.08) | 700.38 Da | Deletion sequence missing one Trp |
| des-Phe (M − 147.07) | 739.39 Da | Deletion sequence missing one Phe |
| des-Lys (M − 128.09) | 758.37 Da | Deletion sequence missing one Lys |
Adduct rows are deconvoluted masses (the shift seen against [M+H]+); the singly charged [M+Na]+ ion itself sits at M + 22.99. Deletion masses alone can't say which copy of a repeated residue is missing.
Short peptides like Hexarelin (6 residues) are easy to make cleanly, so 98% HPLC purity should be the floor, not the goal. The full checklist is in how to read a peptide COA.
Hexarelin-specific things to watch
Hexarelin is a six-residue amidated peptide containing 2-methyl-D-tryptophan, about 887.0 Da.
It is exactly one methyl group (about 14 Da) heavier than GHRP-6. A COA result near 873 Da on a hexarelin product suggests GHRP-6 instead.
Expect [M+H]⁺ near 887.5 m/z and [M+2H]²⁺ near 444.2 m/z.
Hexarelin carries two tryptophan-type residues (2-methyl-D-tryptophan and tryptophan), so watch for oxidation at +16 Da (near 902.5 Da monoisotopic) and +32 Da (two oxidations, or one tryptophan converted to N-formylkynurenine).
A useful oddity: losing hexarelin's 2-methyl-tryptophan and losing one of GHRP-6's tryptophans leave the same 686.4 Da fragment. A peak there can't tell you which product you started with, but the main peak (887.0 vs 873.0 Da) can.
Compounds with similar mass
If a COA's mass is off, compare it with these neighbors. A match to one of them can point to a mislabeled product.
Sources
- PubChem CID 6918297: Hexarelin formula and reference mass.
- CIAAW: Standard atomic weights: Used to calculate average molecular weights.
- NIST CODATA: proton mass: Used to convert m/z charge states to neutral mass.
- PeptideCOACheck methodology: How the checker's thresholds work.
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Frequently asked questions
How do I tell hexarelin from GHRP-6 on a COA?
By the main mass: about 887.0 Da for hexarelin versus 873.0 Da for GHRP-6, exactly one methyl group (14 Da) apart.
What does 444.2 m/z mean on a hexarelin COA?
The [M+2H]2+ ion of the 886.5 Da (monoisotopic) molecule.
What does a hexarelin peak near 902 Da mean?
Oxidation of one of its tryptophan-type residues (+16 Da).
For laboratory research use only. This page describes analytical chemistry data. It is not medical advice and makes no claim about effects in humans or animals.