Comparison
Matrixyl vs. Retatrutide
Two peptides side-by-side — identity, evidence base, legal status and known adverse events.
Identity
Category
Cosmetic
Metabolic
CAS no.
214047-00-4
2381089-83-2
Molecular weight
802.06 g/mol
4731.6 g/mol
Half-life
no data
144 h
Sequence
Palmitoyl-Lys-Thr-Thr-Lys-SerY-Aib-EGTFTSDYSIYLDKQAAQDFVQWLLDTGPSSGAPPPSMechanism of action
Matrixyl
KTTKS is a fragment of the procollagen I sequence and appears to be part of a feedback mechanism in fibroblasts: elevated concentrations signal intact collagen synthesis and downregulate new synthesis, while low concentrations stimulate it. In cell-culture studies, stimulation of collagen types I/III, elastin, fibronectin and glycosaminoglycans has been documented. The palmitoyl modification is intended to improve skin penetration; effect at the site of action (dermal fibroblasts) depends on permeation.
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 RCT
Human RCT
Studies
5
5
of which in humans
2
4
Effects recorded
3
4
Open conflicts
0
0
Documented adverse events
1
2