Comparison
Melanotan II vs. Retatrutide
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Research other
Metabolic
CAS no.
121062-08-6
2381089-83-2
Molecular weight
1024.18 g/mol
4731.6 g/mol
Half-life
1 h
144 h
Sequence
Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-NH2Y-Aib-EGTFTSDYSIYLDKQAAQDFVQWLLDTGPSSGAPPPSMechanism of action
Melanotan II
Melanotan II binds non-selectively to all five melanocortin-receptor subtypes (MC1R-MC5R). Via MC1R in melanocytes, eumelanin synthesis is stimulated (pigmenting effect). Via MC4R and MC3R in the CNS, appetite, sexual function and blood pressure are modulated. The cyclic structure and D-amino acids increase stability compared to natural α-MSH.
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
5
5
of which in humans
5
4
Effects recorded
4
4
Open conflicts
0
0
Documented adverse events
3
2