Comparison

GHRP-2 vs Ipamorelin

Function

While GHRP-2 is used in research to induce robust GH pulses and study anabolic and metabolic effects; clinically developed as pralmorelin for GH deficiency diagnostics6272, Ipamorelin is investigated for producing moderate, physiologic-like GH pulses useful for studying anabolic, body-composition, and recovery effects with a relatively clean endocrine side-effect profile compared with earlier GHRPs16.

Mechanism

While GHRP-2 works as a second-generation hexapeptide growth hormone–releasing peptide that mimics ghrelin by agonizing GHSR-1a, strongly stimulating pulsatile GH release and modestly raising prolactin, ACTH, and cortisol62723096, Ipamorelin is a third-generation pentapeptide growth hormone secretagogue that selectively agonizes the ghrelin (GHSR-1a) receptor to trigger controlled, GH-specific pituitary release with minimal effects on cortisol or prolactin16269596.

Length and Sequence

GHRP-2 is 6 amino acids long, whereas Ipamorelin is shorter as it has a length of 5 amino acids. GHRP-2 is made up of a sequence of Alanine, D-2-Nal, Alanine, Tryptophan, Phenylalanine, Lysine. Ipamorelin is made up of a sequence of Aib, Histidine, D-2-Nal, Phenylalanine, Lysine.

Receptor

GHRP-2

Ghrelin/growth hormone secretagogue receptor (GHSR-1a) 309596104

Ipamorelin

Ghrelin/growth hormone secretagogue receptor type 1a (GHSR-1a)169596104

Organism or Origin

GHRP-2

Synthetic met-enkephalin–derived hexapeptide3072

Ipamorelin

Fully synthetic peptide ghrelin mimetic16

Gene

GHRP-2

GHSR

Ipamorelin

GHSR

Sources

30GHRP-6 - Wikipedia, https://en.wikipedia.org/wiki/GHRP-6
62GHRP-2: Potent Growth Hormone Releasing Peptide Guide, https://www.peptidepedia.org/performance/ghrp-2
72GHRP-2 Technical Data - Molecular Specs - Peptide Initiative, https://peptideinitiative.com/peptides/ghrp-2/technical
96Growth Hormone Secretagogue Receptor - ScienceDirect.com, https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/growth-hormone-secretagogue-receptor
16Ipamorelin peptide: A gentle pulse, but is it strong enough?, https://oathpeptides.com/2025/11/05/ipamorelin-peptide-a-gentle-pulse-but-is-it-strong-enough/
96Growth Hormone Secretagogue Receptor - ScienceDirect.com, https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/growth-hormone-secretagogue-receptor