Comparison
GHRP-6 vs. Retatrutide
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Growth
Metabolic
CAS no.
87616-84-0
2381089-83-2
Molecular weight
873.02 g/mol
4731.6 g/mol
Half-life
0.4 h
144 h
Sequence
His-D-Trp-Ala-Trp-D-Phe-Lys-NH2Y-Aib-EGTFTSDYSIYLDKQAAQDFVQWLLDTGPSSGAPPPSMechanism of action
GHRP-6
GHRP-6 is a high-affinity agonist of the growth-hormone secretagogue receptor 1a (GHSR-1a) — the same receptor later shown to bind the endogenous hormone ghrelin. The identification of GHRP-6 as a pharmacological anchor led to cloning of GHSR in 1996 and the discovery of ghrelin itself in 1999. GHRP-6 stimulates pituitary GH secretion via a pathway independent of GHRH and can be combined synergistically with GHRH. Via GHSR in the hypothalamus it additionally activates NPY/AgRP neurons, producing an orexigenic (appetite-stimulating) effect in animal models.
Retatrutide
Retatrutide is a 39-amino-acid peptide with agonism at three incretin/energy-balance receptors: GLP-1R (insulin secretion, satiety), GIPR (insulin sensitivity, lipid metabolism) and the glucagon receptor (energy expenditure, lipolysis). The added glucagon activation is intended to raise catabolic energy expenditure while concurrent GLP-1/GIP action compensates the hyperglycaemic effect. Albumin binding via a fatty-acid side chain enables weekly dosing.
Evidence base
Highest evidence
Human trial
Human RCT
Studies
4
5
of which in humans
2
4
Effects recorded
4
4
Open conflicts
1
0
Documented adverse events
2
2