Comparison

Argireline vs. Matrixyl

Two peptides side-by-side — identity, evidence base, legal status and known adverse events.

Identity

Mechanism of action

Argireline

Argireline is a synthetic hexapeptide whose sequence corresponds to the N-terminus of the SNAP-25 protein. In vitro it has been shown to competitively inhibit SNARE complex formation (necessary for vesicle fusion in neurotransmitter release). Topical application is intended — given very limited skin permeation — to attenuate cholinergic signalling at the neuromuscular endplate. The effect is orders of magnitude weaker than intramuscular botulinum toxin; the clinical translatability of the in-vitro observations to the skin microenvironment is contested.

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.