Sermorelin vs CJC-1295
Two GHRH-analog peptides referenced in growth-hormone-axis research — what differs structurally and what that means for half-life.
Both are GHRH analogs
Sermorelin is a 29-amino-acid analog corresponding to the active fragment of growth-hormone-releasing hormone. CJC-1295 is a modified analog of the same fragment, engineered to be more stable in circulation.
Half-life is the key structural difference
Sermorelin has a short half-life. CJC-1295 (with DAC) extends that substantially via a drug-affinity-complex modification. The "no-DAC" form of CJC-1295 (sometimes called Mod GRF 1-29) sits between the two in terms of duration.
Research framing
The two are usually studied as members of the same GHRH-analog class rather than as direct substitutes. Researchers often co-reference them with the GH-secretagogue Ipamorelin.