CJC-1295 + Ipamorelin: The "GH Stack" Explained

"GH stack" is one of the more common phrases you'll come across in growth-hormone-axis peptide research discussion, almost always referring to one specific pairing: CJC-1295 and Ipamorelin. Unlike some peptide nicknames that are purely aesthetic, this one is descriptive of an actual mechanism-level rationale - the two compounds act on two different receptors that both feed into GH secretion.

Two receptors, one axis

CJC-1295 (with DAC) is a synthetic analogue of GHRH(1-29), the growth-hormone-releasing hormone. It targets the GHRH receptor on pituitary somatotrophs, and its DAC modification - a maleimidopropionic acid linker - lets it bind circulating albumin, extending its active half-life from minutes to days.

Ipamorelin is a selective pentapeptide agonist of the ghrelin receptor (GHS-R1a) - a completely separate receptor from GHRH-R, but one that also triggers GH release when activated. Published research also describes Ipamorelin as having a non-stimulatory profile in ACTH and cortisol assays, which distinguishes it from earlier-generation growth-hormone-releasing peptides (GHRPs) that showed more off-target receptor activity.

Why researchers study them together

Because CJC-1295 and Ipamorelin enter the growth-hormone axis through two distinct receptor systems - GHRH-R and GHS-R1a respectively - studying them together lets researchers examine how the two pathways interact when both are engaged, rather than only observing each receptor's effect in isolation. That's the actual research logic behind the "GH stack" pairing, independent of the nickname.

• CJC-1295 - GHRH receptor agonist, extended half-life via albumin binding, sustained signalling duration.
• Ipamorelin - ghrelin receptor (GHS-R1a) agonist, selective profile, non-stimulatory in ACTH/cortisol assays.

What the evidence shows for each, and together

Individually, CJC-1295 has published data demonstrating significant, sustained increases in GH and IGF-1 levels persisting for six to eight days from a single dose in preclinical models. Ipamorelin's research base focuses on its receptor selectivity and the GH pulse pattern it produces via GHS-R1a activation. Dedicated combination studies - measuring the two compounds administered together rather than each alone - are less common in the published literature than the individual mechanism-of-action data for each compound.

What we still don't know

As with most peptide combination research, the open question is whether dual-receptor engagement produces additive, synergistic, or simply parallel effects on GH secretion - a question that requires dedicated combination-arm studies rather than inference from separate single-compound data.

Compliance reminder

CJC-1295 and Ipamorelin are supplied by Pillar Research for in vitro laboratory research use only, under the Research Use Only (RUO) framework. Neither is listed on the Australian Register of Therapeutic Goods (ARTG), and neither is intended for human or animal consumption, therapeutic use, or diagnostic procedures.

Researching the GH axis? View CJC-1295 with DAC and Ipamorelin, or see the Muscle Growth & Sleep Kit, which bundles both for comparative research.