CJC-1295 and Ipamorelin, why they're usually stacked and what each is actually doing
This stack gets recommended constantly and the explanations for why are usually incomplete. Here's the more detailed version.
CJC-1295 is a GHRH analog, growth hormone releasing hormone. It extends the half-life of endogenous GHRH, which means more sustained stimulation of growth hormone release from the pituitary. On its own it produces a broader, more sustained GH pulse.
Ipamorelin is a GHRP, growth hormone releasing peptide. It works through the ghrelin receptor (GHSR-1a) to stimulate GH release and also suppresses somatostatin, which is the main inhibitor of GH secretion. On its own it produces a clean, relatively selective GH pulse with less effect on cortisol and prolactin than older GHRPs like GHRP-2 or GHRP-6.
Why they're stacked: the two mechanisms are complementary. CJC extends the duration and amplitude of GH stimulation through one pathway. Ipamorelin amplifies the pulse and reduces the somatostatin brake through another. Together they produce a larger and more sustained GH release than either alone.
Timing for sleep use: typically dosed before bed because the largest natural GH pulse occurs in early slow-wave sleep. Dosing aligned with this timing amplifies a natural process rather than creating an artificial one.
The caveat that matters: GH peptides work through endogenous GH release. They're not exogenous HGH. The ceiling is your own pituitary's capacity to produce GH, which varies by age and individual physiology.