Sermorelin vs CJC-1295 (no DAC): four substitutions apart

Both peptides are GHRH(1-29), the active 29-residue fragment of growth hormone releasing hormone. Sermorelin is that sequence as nature wrote it. CJC-1295 no DAC changes four residues to make it last longer in research models. The edits add ten daltons.

Twenty-five residues in common

GHRH(1-29) is the shortest fragment of the 44-residue hormone that keeps full activity in research models. Sermorelin is exactly that fragment with an amidated C-terminus.

CJC-1295 no DAC, also called Modified GRF (1-29), keeps the same backbone and substitutes four positions: D-Ala for Ala at 2, Gln for Asn at 8, Ala for Gly at 15 and Leu for Met at 27. Position 2 is the one that matters most. The DPP-4 enzyme removes the first two residues of native GHRH within minutes; a D-amino acid at 2 stops it. The others remove an oxidation-prone methionine and a site that deamidates.

Ten daltons apart

The sulfur in sermorelin's formula is its methionine at 27; the CJC-1295 version swapped it for leucine and has none. The ten dalton difference is 0.3% of the mass, and an identity check tolerates a tenth of a percent. So the mass spec separates them, but this is the closest pair on the site and the one where reading the report carefully matters. How to read a peptide lab report shows the line to check.

Where each one fits

Sermorelin is the reference molecule, the native fragment. CJC-1295 no DAC is the stabilised one, and it is the version paired with a ghrelin agonist in the CJC-1295 + Ipamorelin blend. The DAC version goes further still and lasts days.

Native or stabilised

Sermorelin is native GHRH(1-29). CJC-1295 no DAC is the same fragment with four stabilising edits and ten more daltons. Choose native or stabilised, and check the mass line on the report.

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