Ipamorelin and GHRP-6 are both GHRPs (ghrelin-mimetic growth hormone releasing peptides). They produce similar GH pulses but have very different side-effect profiles. GHRP-6 stimulates appetite and raises cortisol/prolactin; Ipamorelin does neither.
Ipamorelin
GHRP-6
Amino acid length
5 aa
6 aa
Molecular weight
~711 Da
~872 Da
Cortisol increase
Negligible
Mild - moderate
Prolactin increase
Negligible
Mild
Appetite stimulation
None
Strong (hunger spike)
Selectivity for GH receptor
High
Moderate
Typical research dose
100-300 mcg per pulse
100-200 mcg per pulse
Per-mg cost
Higher
Lower
Common substitution risk
Sold as GHRP-2 (cheaper)
Sold AS Ipamorelin (cost arbitrage)
Verdict
Ipamorelin is the cleaner GHRP - used as the default in CJC-1295 stacks because it doesn't raise cortisol or prolactin. GHRP-6 is the appetite-tool of choice when hunger is the goal. The biggest QC failure: GHRP-6 vials sold as Ipamorelin to pad margin. LC-MS catches it via the ~160 Da mass delta.
Frequently asked questions
Why pay more for Ipamorelin?
Because the side-effect profile is cleaner - no cortisol/prolactin rise, no appetite spike. For chronic dosing the trade-off matters.
Can I tell them apart visually?
No - both are white lyophilised powders. Only LC-MS or NMR can distinguish them.
Is GHRP-6 dangerous?
Not at research doses, but the cortisol/prolactin response is real and not what most users want. Test before assuming what's in the vial.