GHRP-6 vs Ipamorelin

GHRP-6

The hungry one. A ghrelin-mimetic that delivers a real GH pulse but is far better known for the appetite avalanche that arrives twenty minutes after the injection.

Best for

Best when you specifically want the strong appetite stimulus, or want the cheaper legacy option.

Ipamorelin

A selective ghrelin-receptor agonist that triggers a GH pulse without raising cortisol or prolactin — the property that made it the default GHRP and pushed the older, dirtier GHRPs to the margins.

Best for

Best for almost everything else — selective GH release, no hunger spike, no cortisol/prolactin lift.

GHRP-6

Small short-term studies from the late 1990s confirmed that GHRP-6 raises GH in healthy adults and stimulates food intake. The appetite finding has been replicated. No large or long-term efficacy or safety trials exist; community use is the bulk of the chronic-dosing track record.

Ipamorelin

Original pharmacology work by Raun and colleagues (1998) established the GH-selectivity profile — the absence of cortisol and prolactin lift is what differentiates this peptide from the older GHRPs and the data on that point is reproducible. Long-term outcome trials in healthy adults are not the literature's strong suit. The pulse pharmacology is tight; the chronic body-recomp evidence is anecdotal-plus-mechanism rather than RCT-based.