Sermorelin vs CJC-1295 — GHRH Analog Comparison
Two GHRH-analog peptides referenced in growth-hormone-axis research — what differs structurally, and why half-life changes what is being studied.
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.
That difference is not a convenience detail. A receptor stimulated in short pulses and the same receptor stimulated continuously are two different experimental conditions, which is why duration is the first column to read when comparing anything in this class.
Side by side, from the catalog
| Specification | Sermorelin | CJC-1295 | CJC-1295 (No DAC) |
|---|---|---|---|
| Compound class | GHRH analog (growth-hormone-releasing hormone analog) | GHRH analog (long-acting, with Drug Affinity Complex / DAC) | GHRH analog (short-acting modified GHRH(1-29), aka Mod GRF 1-29) |
| Length (aa) | 29 | 30 | 29 |
| Molecular weight | 3357.9 g/mol | Approximately 3647 g/mol (with DAC linker) | Approximately 3368 g/mol |
| Reported half-life | Short, on the order of minutes (reported approximately 10-20 minutes) | Substantially extended vs native GHRH; reported on the order of days (approximately 6-8 days) due to albumin binding via DAC | Short, on the order of tens of minutes (reported approximately 30 minutes), longer than native GHRH but far shorter than the DAC version |
A cell reading "Not listed" is a gap in the published record. PeptiDex records a specification only where a source documents it, and never substitutes an estimate.
Stated mechanisms
Sermorelin — Sermorelin is an agonist of the GHRH receptor on anterior-pituitary somatotrophs, stimulating the synthesis and pulsatile secretion of endogenous growth hormone.
CJC-1295 — CJC-1295 is a GHRH-receptor agonist that stimulates pulsatile GH secretion from the pituitary.
CJC-1295 (No DAC) — This peptide is a GHRH-receptor agonist that stimulates pulsatile GH release from the pituitary.
What each entry's record says separates it
- Sermorelin — Sermorelin is a GHRH-receptor agonist (GHRH 1-29) rather than a ghrelin-receptor GHRP, and it is shorter-acting than modified GHRH analogs such as CJC-1295 or tesamorelin.
- CJC-1295 — The DAC version's albumin binding gives it a far longer half-life (days) than the no-DAC 'Mod GRF 1-29' (minutes), making it the long-acting member of the CJC-1295 family.
- CJC-1295 (No DAC) — The absence of the DAC albumin-binding group makes this a short-acting, pulse-generating GHRH analog, in direct contrast to the long-acting DAC version of CJC-1295.
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, which acts at a different receptor entirely.
Full records: Sermorelin, CJC-1295, CJC-1295 (No DAC). The whole class sits on the Growth & GH-Axis hub.