Comparison

CJC-1295 vs Ipamorelin

Reviewed 22 October 2026 · How we research

CJC-1295 and ipamorelin are rarely discussed apart, because they are sold together as the “CJC/Ipa” blend. Understanding what each does explains why.

CJC-1295 vs Ipamorelin at a glance

How they work

CJC-1295

Both forms bind GHRH receptors on the pituitary and increase growth hormone release, which raises IGF-1 from the liver. The short no-DAC form mimics a natural GHRH pulse; the DAC form produces sustained elevation of baseline growth hormone. Combining a GHRH analogue with a ghrelin mimetic like ipamorelin produces a larger GH release than either alone, because the two act on different receptors.

Ipamorelin

Ghrelin, the “hunger hormone”, also stimulates growth hormone through GHS-R1a receptors in the pituitary and hypothalamus. Ipamorelin mimics this specific action. Each dose produces a distinct GH pulse, peaking within about 30–60 minutes. Pairing it with a GHRH analogue (like CJC-1295) amplifies the pulse because the two pathways are synergistic.

Side effects compared

CJC-1295

In the human DAC studies the most common effects were injection-site reactions, flushing, headache and transient water retention. Raised growth hormone and IGF-1 can affect blood glucose. Long-term safety has never been studied.

Ipamorelin

In the postoperative ileus trials, adverse events were similar to placebo. Commonly reported effects in non-clinical use include headache, flushing, water retention and injection-site irritation. Raised GH and IGF-1 may reduce insulin sensitivity.

Bottom line

The two act on separate receptors, so together they produce a larger GH pulse than either alone. Blends normally use CJC-1295 without DAC, so the combined effect is pulsatile.