Overview
Following subcutaneous administration, absorption is relatively rapid with peak plasma concentrations achieved within 15-20 minutes. The compound's ~30-minute half-life results from a balance between enhanced DPP-IV resistance and the absence of the cysteine-maleimide DAC linker that would otherwise facilitate albumin binding. Peak GH secretion occurs approximately 15-45 minutes post-injection, with GH pulse duration of 90-180 minutes. Endogenous somatostatin tone significantly modulates response amplitude, which is why co-administration with a GHRP (e.g., Ipamorelin or GHRP-2) — which also inhibits somatostatin release — produces synergistic GH elevations of 3-10x compared to either peptide alone. Tachyphylaxis is minimal with pulsatile dosing protocols due to receptor recycling between pulses, unlike continuous GHRH infusion protocols.
Proposed mechanism
CJC-1295 without DAC binds to and activates the GHRH receptor (GHRHR) on somatotroph cells in the anterior pituitary, triggering a Gs protein-coupled signaling cascade that elevates intracellular cAMP via adenylyl cyclase activation, ultimately stimulating the synthesis and pulsatile release of growth hormone (GH). Unlike native GHRH (1-44), the four amino acid substitutions (Ala2→D-Ala, Gln8→Ala, Ala15→Ala, Leu27→Val) protect the peptide from enzymatic cleavage by dipeptidyl peptidase IV (DPP-IV) and other proteases, extending its half-life to approximately 30 minutes. The resulting GH pulse drives downstream IGF-1 production primarily in the liver, which mediates many of the anabolic, lipolytic, and recovery-related effects.
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]
Stimulation of growth hormone (GH) secretion by a novel synthetic GH-releasing peptide: comparison with GH-releasing hormone (GHRH) and Hexarelin
· Journal of Endocrinology · 1997
- [2]
Effects of once weekly dosing of a growth hormone-releasing hormone analog (CJC-1295) on growth hormone and insulin-like growth factor-1 levels in healthy adults
· Journal of Clinical Endocrinology & Metabolism, 91(3):799-805 · 2006
- [3]
Tesamorelin: a growth hormone-releasing factor analogue for HIV-associated lipodystrophy
· Expert Opinion on Pharmacotherapy, 12(14):2237-2251 · 2011
- [4]
Growth hormone-releasing hormone: clinical studies and therapeutic aspects
· Endocrine Reviews, Endocrine Society · 1998
- [5]
Ghrelin and the GH secretagogue receptor: from discovery to biomarker
· Frontiers in Endocrinology · 2014
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.