Comparison

Ipamorelin vs Retatrutide

Function

While 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, Retatrutide is an investigational agent that produces very large body-weight reductions in early trials by simultaneously engaging GLP-1R, GIPR, and GCGR to enhance satiety, energy expenditure, and glycemic control2575.

Mechanism

While Ipamorelin works as 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, Retatrutide is a triple incretin agonist peptide derived from a GIP backbone and engineered to activate GLP-1, GIP, and glucagon receptors, with non-natural residues and fatty-acid conjugation that confer long half-life and balanced multi-receptor signaling256575.

Length and Sequence

Ipamorelin is 5 amino acids long, whereas Retatrutide is longer as it has a length of 39 amino acids. Ipamorelin is made up of a sequence of Aib, Histidine, D-2-Nal, Phenylalanine, Lysine. Retatrutide is made up of a sequence of sequence data not available in the current dataset.

Receptor

Ipamorelin

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

Retatrutide

GLP-1 receptor (GLP1R), GIP receptor (GIPR), and glucagon receptor (GCGR) 256575

Organism or Origin

Ipamorelin

Fully synthetic peptide ghrelin mimetic16

Retatrutide

Synthetic multi-agonist peptide inspired by human incretins and glucagon657580

Gene

Ipamorelin

GHSR

Retatrutide

Not assigned in the current dataset.

Sources

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
25What is the mechanism of action of Retatrutide? - Patsnap Synapse, https://synapse.patsnap.com/article/what-is-the-mechanism-of-action-of-retatrutide
65Retatrutide Molecular Structure and Properties | Peptide Protocol Wiki, https://www.peptideprotocolwiki.com/peptides/retatrutide/molecule
75Retatrutide: The Triple Hormone Agonist (GLP-1/GIP/Gluc, https://formblends.com/research/glp-1/retatrutide-triple-agonist-guide
80GLP-1 Localisation and Proglucagon Gene Expression in ..., https://pmc.ncbi.nlm.nih.gov/articles/PMC6200298/