Comparison. Research use only.
CJC-1295 (DAC) vs Ipamorelin / CJC-1295
This is the single most common point of confusion in GH secretagogue research. CJC-1295 with DAC and CJC-1295 without DAC are different molecules with very different pharmacokinetics. The DAC (Drug Affinity Complex) version binds covalently to serum albumin, the most abundant protein in blood, which keeps it in plasma for days. The no-DAC form, typically blended with Ipamorelin, clears in hours and produces a pulsatile rather than sustained profile.
CJC-1295 (DAC)
CJC-1295 is a synthetic analog of growth hormone-releasing hormone, built on the biologically active N-terminal 1-29 fragment of human GHRH. It acts as an agonist at the GHRH receptor, a class B G-protein-coupled receptor found on anterior pituitary somatotrophs, the pituitary cells that make growth hormone. When the receptor is occupied, intracellular cAMP rises and the cell makes and releases its own growth hormone in pulses, which in turn drives hepatic IGF-1 production. Four amino acid substitutions relative to native GHRH(1-29) make the peptide resistant to enzymatic inactivation. The most important is the D-alanine at position 2, which blocks cleavage by dipeptidyl peptidase-IV, the main route by which GHRH is broken down in plasma. The DAC variant also carries a maleimidopropionyl group on a C-terminal lysine. That group reacts selectively with the free thiol of Cys34 on circulating serum albumin, forming a covalent bioconjugate in the body. Jette and colleagues established this albumin-tethering strategy as the basis for the compound's long stay in plasma, and Teichman and colleagues reported an estimated half-life of 5.8 to 8.1 days in healthy adults. Because the mechanism acts upstream at the pituitary rather than supplying growth hormone from outside, output stays subject to negative feedback from somatostatin and IGF-1. Ionescu and Frohman reported that the frequency and magnitude of GH secretory pulses were unaltered despite continuous receptor stimulation, with basal GH rather than pulse amplitude accounting for the increase. CJC-1295 without DAC, commonly marketed as modified GRF 1-29, lacks the maleimide group and therefore does not form the albumin conjugate, which gives it a fundamentally different pharmacokinetic profile.
Ipamorelin / CJC-1295
This combination targets two distinct but synergistic nodes in the growth hormone (GH) axis. CJC-1295 is a synthetic analog of growth hormone-releasing hormone (GHRH(1–29)) carrying four amino acid substitutions that make it resistant to the enzyme DPP-4, which extends its half-life. The non-DAC version (also known as mod-GRF(1–29)) has a half-life of ~30 minutes. The DAC (Drug Affinity Complex) version binds covalently to plasma albumin through a maleimide linker, giving it a half-life of approximately 6–8 days and allowing once or twice-weekly dosing. CJC-1295 acts on the GHRH receptor (GHRHR) on pituitary somatotrophs, the pituitary cells that release GH, and increases the size of each GH pulse. Ipamorelin is a selective growth hormone secretagogue pentapeptide. It acts as a partial agonist at the ghrelin receptor (GHS-R1a) and increases how often GH pulses occur, working through a different intracellular pathway (Gq/PKC rather than Gs/cAMP). Ipamorelin is also highly selective for that receptor: at research doses it does not appreciably stimulate ACTH, cortisol, or aldosterone release, unlike older GH secretagogues (GHRP-6, GHRP-2). Giving CJC-1295 (pulse size) and ipamorelin (pulse frequency) together produces GH release patterns that more closely mimic youthful physiological pulsatility. In preclinical and small human studies, the pair raised GH and IGF-1 more than either agent alone.
Other research peptide comparisons
Both compounds in stock at Veridian. 99%+ HPLC purity, same-day US shipping.
Browse all research peptides →