Source comparison
ACTH and Cortisol Co-secretion: GHRP-6 vs CJC-1295
One of the most important off-target distinctions is ACTH/cortisol co-secretion. GHRP-6 at standard research doses (1–100 µg/kg) stimulates ACTH secretion by approximately 2.5–3.0-fold and cortisol by approximately 1.8–2.2-fold via GHS-R1a expression on cortic
This comparison does not assign a generated winner or score.
- One of the most important off-target distinctions is ACTH/cortisol co-secretion. GHRP-6 at standard research doses (1–100 µg/kg) stimulates ACTH secretion by approximately 2.5–3.0-fold and cortisol by approximately 1.8–2.2-fold via GHS-R1a expression on corticotrophs and direct adrenocortical GHS-R1a activation. This is a consistent, dose-dependent effect that constitutes a confounding variable in any metabolic or immune research endpoint where cortisol is relevant.
- CJC-1295 does not stimulate ACTH/cortisol secretion above baseline — GHRHR is not expressed on corticotrophs, and CJC-1295 has no affinity for GHS-R1a. This makes CJC-1295 a cleaner tool when GH-specific (non-cortisol-confounded) effects are required. For studies on immune function, glucose metabolism, or HPA axis where cortisol would independently modulate outcomes, CJC-1295 is mechanistically preferable as the pure GHRHR agonist control.
- Conversely, in research specifically examining the interaction between GH axis activation and cortisol co-secretion — such as HPA/somatotropic axis crosstalk, stress response biology, or catabolic-anabolic balance — GHRP-6 provides a more physiologically complex model. The ACTH effect of GHRP-6 is GHS-R1a mediated: [D-Lys³]-GHRP-6 (a GHS-R1a antagonist) blocks both GH and ACTH responses, while the GHRHR antagonist [D-Arg2,Lys26,Nle27]-GHRH(1–29) blocks GH but not ACTH — confirming the GHS-R1a vs GHRHR attributions.