Sermorelin vs CJC-1295: GHRH Analog Comparison
Both are GHRH analogs that target the same receptor — but sermorelin is the parent fragment while CJC-1295 adds stabilizing modifications. Here's how the two compare in research terms.
Sermorelin and CJC-1295 are both GHRH analogs — they bind the same growth-hormone-releasing-hormone receptor and study the same pathway. The difference is structural: sermorelin is the parent GHRH(1-29) fragment, while CJC-1295 adds modifications that make it more stable and longer-acting. This research-use-only comparison covers how sermorelin and CJC-1295 differ in sequence, stability, and kinetics, and which research questions each is suited to.
Same receptor, same family
Both compounds are analogs of growth-hormone-releasing hormone, and both bind the GHRH receptor on pituitary somatotrophs to raise GH availability through the cyclic-AMP / protein-kinase-A pathway. So at the level of the target pathway, sermorelin and CJC-1295 are studied as members of the same class with the same mechanism of action. The interesting differences are not in what they do but in how long they survive to do it — that is, in structure and kinetics.
Sermorelin: the GHRH(1-29) parent
Sermorelin is GHRH(1-29) — the first 29 amino acids of native GHRH, which is the minimal fragment that retains full receptor activity. Because it is essentially the unmodified active fragment, it is rapidly degraded by enzymes such as dipeptidyl peptidase-4 (DPP-4), which cleaves the peptide near its N-terminus, giving sermorelin a very short half-life of only a few minutes in reported models. It is the closest analog to the endogenous signal, which is precisely its value: it models native GHRH biology with minimal structural deviation.
CJC-1295: the stabilized analog
CJC-1295 starts from the same GHRH(1-29) backbone but adds four amino-acid substitutions that resist DPP-4 cleavage — this stabilized form is modified GRF 1-29, the no-DAC CJC-1295. Those substitutions push the half-life from minutes (sermorelin) to roughly half an hour. The optional Drug Affinity Complex (DAC) version extends the half-life much further — to days — by binding albumin. For that DAC-versus-no-DAC distinction, see CJC-1295 DAC vs No-DAC, which breaks down how each form behaves over time.
Side-by-side
- Sequence: sermorelin is unmodified GHRH(1-29); CJC-1295 is GHRH(1-29) with four stabilizing substitutions
- Receptor: both target the GHRH receptor via cAMP/PKA — same pathway, same mechanism
- Stability: sermorelin is DPP-4-labile; CJC-1295 resists DPP-4 cleavage
- Half-life: sermorelin minutes; CJC-1295 no-DAC ~30 min; CJC-1295 DAC ~6–8 days
- Research framing: sermorelin as the native-like signal; CJC-1295 as the durability-optimized analog
- Common pairing: either can be combined with ipamorelin to engage the ghrelin pathway as well
Why the stability difference matters
The practical consequence of DPP-4 sensitivity shows up in how reproducible a signal is across an experiment. Sermorelin's rapid clearance means its GHRH input is brief and tightly time-locked — useful when modeling a single, native-like pulse, but harder to hold steady. CJC-1295's resistance to DPP-4 gives a more durable, reproducible input window. Researchers weigh that reproducibility against fidelity to native GHRH structure when choosing between the two.
Which one for a given study?
If a protocol needs the closest model to native GHRH signaling, sermorelin is the GHRH(1-29) parent and the most faithful structural match. If durability and resistance to enzymatic clearance are the variables of interest, CJC-1295 is the stabilized analog — and either form is frequently paired with ipamorelin in the CJC-1295 + ipamorelin stack to engage the ghrelin receptor alongside the GHRH receptor.
Both are GHRH analogs, not secretagogues
A point of frequent confusion: sermorelin and CJC-1295 are GHRH analogs, which is a different category from the ghrelin-receptor secretagogues like ipamorelin. GHRH analogs raise the releasable pool of GH and prime the somatotroph through the GHRH receptor; secretagogues trigger release through GHS-R1a. That is why a GHRH analog and a secretagogue are studied together rather than as substitutes — they occupy complementary roles in the same release machinery. Comparing sermorelin to CJC-1295 is a within-class comparison of two GHRH analogs; comparing either to ipamorelin would be a cross-class one.
Reconstitution and quality
Both are supplied lyophilized and reconstituted with bacteriostatic water for in-vitro use; the reconstitution calculator handles the concentration and draw-volume math for any vial size. Every lot ships lyophilized in multi-vial research kits from our US facility within 48 hours with tracking.
Frequently asked questions
What is the difference between sermorelin and CJC-1295?
Both are GHRH analogs targeting the same GHRH receptor, but sermorelin is the unmodified GHRH(1-29) parent fragment with a very short half-life, while CJC-1295 adds four stabilizing substitutions (and optionally a DAC) that resist enzymatic clearance and extend its half-life. Both are research-use-only.
Is sermorelin or CJC-1295 longer-acting?
CJC-1295. Sermorelin is rapidly degraded by DPP-4 (half-life of minutes), whereas CJC-1295's stabilizing modifications extend its half-life — to roughly 30 minutes for the no-DAC form and several days for the DAC form, in reported models.
Do sermorelin and CJC-1295 act on the same receptor?
Yes. Both are GHRH analogs that bind the GHRH receptor on pituitary somatotrophs and study the same growth-hormone-release pathway via cAMP/PKA; they differ in structure and kinetics, not in target or mechanism.