GH Stack Research

Ionescu M, Frohman LA

The primary human study of CJC-1295 — the GHRH component of the GH Stack. Demonstrated sustained, dose-dependent GH and IGF-1 elevation lasting 6–8 days from a single injection, with IGF-1 increasing 1.5–3 fold above baseline. CJC-1295’s albumin-binding mechanism provides the prolonged “GH amplitude amplification” that forms one half of the stack’s dual-pathway mechanism.

Raun K, Hansen BS, Johansen NL, et al.

The landmark selectivity study for Ipamorelin — the GHRP component of the GH Stack. Established that Ipamorelin produces robust GH release with approximately 90% less cortisol elevation and no meaningful ACTH or prolactin response compared to older GHRPs. This clean hormonal profile is why Ipamorelin became the default GHRP for stacking — it adds GH pulse triggering through the ghrelin receptor without the cortisol and appetite side effects of GHRP-6 or GHRP-2.

Jørgensen JOL, et al.

A mechanistic study demonstrating supra-additive GH release when GHRH analogs and GHSR agonists are co-administered — the scientific foundation for the GH Stack’s design. Co-administration produced 2–4x greater GH area under the curve compared to either compound given in isolation, with the effect being additive to synergistic depending on timing. The biological explanation: CJC-1295 activates GHRHR and raises intracellular cAMP (via PKA), while Ipamorelin activates GHS-R1a and raises intracellular calcium (via PKC). When both second messenger cascades fire simultaneously, the somatotroph cell response is amplified beyond what either signal produces alone.

Ishida J, Saitoh M, Ebner N, et al.

A comprehensive review of the GH secretagogue class providing clinical context for the CJC-1295 + Ipamorelin combination. The paper covers the evolution from native GHRH and ghrelin to long-acting analogs and selective GHRPs — documenting how the dual-pathway approach became the preferred research and clinical protocol for GH axis optimization. It also addresses why the combination is considered safer than direct GH administration — stimulating endogenous production preserves natural feedback mechanisms and avoids supraphysiological IGF-1 spikes.