Overview
Following subcutaneous administration, both peptides are absorbed through the interstitial fluid into systemic circulation. CJC-1295 no DAC reaches peak plasma concentration within 15–30 minutes with a half-life of ~30 minutes, making dosing timing critical for aligning with natural GH pulse windows. Ipamorelin has a slightly longer half-life of ~2 hours. The resulting GH pulse elevates systemic IGF-1 (primarily hepatic origin) within 2–6 hours post-injection, with IGF-1 elevation persisting for 12–24 hours following repeated dosing protocols. Unlike exogenous HGH, this approach preserves pulsatile secretion, which is important for avoiding IGF-1 receptor desensitization and maintaining physiological GH axis feedback integrity via somatostatin counter-regulation.
Proposed mechanism
CJC-1295 (without DAC), also known as Mod GRF 1-29, binds to GHRH receptors on somatotroph cells in the anterior pituitary, increasing cAMP signaling and priming GH synthesis and release. Ipamorelin acts as a selective ghrelin mimetic, binding to the GHS-R1a receptor and triggering a separate, complementary intracellular calcium-dependent signaling cascade to stimulate GH secretion. Because they act through distinct receptor pathways, co-administration produces a synergistic pulse of GH release that closely mimics the body's natural pulsatile GH secretion, without significantly suppressing endogenous somatostatin.
What the evidence supports
Human data exists but the trials are small, short-term, or not yet replicated.
Graded Human-limited
Human data that exists but is thin: open-label work, single-arm studies, small cohorts, or observational follow-up without randomisation.
Key citations
Representative primary sources, including results that did not favour the compound.
- [1]
Ipamorelin, the first selective growth hormone secretagogue
· Eur J Endocrinol. 139(5):552-558. PMID: 9849822 · 1998
- [2]
CJC-1295, a long-acting growth hormone-releasing factor analogue
· J Clin Endocrinol Metab. 91(3):799-805. Alba M et al. · 2006
- [3]
Growth hormone secretagogues: history, mechanism of action, and clinical development
· JPEN J Parenter Enteral Nutr. 36(1 Suppl):81S-95S · 2012
- [4]
Ghrelin and the GH secretagogue receptor: from discovery to therapeutic development
· Endocrine Reviews, 26(3):439-443 · 2005
Citation records in this build are illustrative placeholders for the design.
Reference information for research purposes. Not medical advice, and not a recommendation to use any compound. Many entries describe substances that are not approved for human use.