Comparison
GHRP-2 vs. Ipamorelin
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Growth
Growth
CAS no.
158861-67-7
170851-70-4
Molecular weight
817.93 g/mol
711.86 g/mol
Half-life
0.5 h
2 h
Sequence
D-Ala-D-2-Naphthyl-Ala-Ala-Trp-D-Phe-Lys-NH2Aib-His-D-2-Nal-D-Phe-Lys-NH2Mechanism of action
GHRP-2
GHRP-2 binds with high affinity to the GH secretagogue receptor (GHSR-1a) in the pituitary and hypothalamus. Activation leads to rapid release of pulsatile growth hormone. Unlike GHRH, GHRP-2 acts via a separate pathway and can be combined synergistically with GHRH to elicit maximal GH responses in provocation tests.
Ipamorelin
Ipamorelin is a selective agonist at the GH secretagogue receptor (GHSR-1a). Compared to GHRP-2 and GHRP-6 its selectivity for the growth-hormone axis is higher; ACTH, cortisol and prolactin are not significantly stimulated in clinical studies. This selectivity was the main reason for its development over older GHRPs.
Evidence base
Highest evidence
Human trial
Human RCT
Studies
4
4
of which in humans
4
3
Effects recorded
3
3
Open conflicts
0
1
Documented adverse events
1
1