K4 Elite
K4 Elite
A lipidated matrikine cosmetic peptide (palmitoyl-KTTKS) derived from a fragment of type I collagen, studied for its ability to signal fibroblasts to increase extracellular-matrix synthesis. The palmitoyl group enhances skin penetration relative to the unmodified peptide.
Matrixyl, whose INCI name is palmitoyl pentapeptide-4 (earlier labeled palmitoyl pentapeptide-3), is a lipidated cosmetic peptide consisting of the pentapeptide KTTKS conjugated to a palmitic-acid (palmitoyl) chain — hence 'pal-KTTKS'. The KTTKS sequence is a fragment of the propeptide region of type I collagen and belongs to the class of 'matrikine' signaling peptides. The palmitoyl group is added to improve lipophilicity and skin penetration. 'Matrixyl 3000' refers to a related commercial blend pairing this concept with additional peptides.
PubChem indexes palmitoyl pentapeptide-4 under CID 9897237, with molecular formula C39H75N7O10 and a molecular weight of approximately 802.1 g/mol. It sits in the cosmetic "skin, hair and beauty" research theme and is studied for its proposed stimulation of extracellular-matrix components such as collagen and glycosaminoglycans. Among cosmetic peptides it has a comparatively substantial published record.
This entry is for laboratory and educational reference only. It reports the proposed mechanism and research context and is not an efficacy claim or a recommendation for human or veterinary use.
Matrixyl is described as a matrikine — a peptide fragment of the extracellular matrix that acts as a signaling molecule. The KTTKS sequence, corresponding to a fragment of type I procollagen, has been reported in fibroblast cell-culture studies to stimulate synthesis of matrix macromolecules including collagen I, collagen III, fibronectin and glycosaminoglycans, effectively feeding back a 'repair' signal to the cell.
The palmitoyl modification increases the peptide's affinity for the lipid-rich stratum corneum, improving its penetration through the skin barrier relative to unmodified KTTKS, which penetrates poorly. The proposed net effect studied in cosmetic science is increased dermal matrix deposition, associated in some studies with measures of skin appearance and roughness.
Katayama et al. (1993) reported in-vitro work showing that the KTTKS peptide, a fragment of type I collagen, stimulated production of collagen and fibronectin in cultured fibroblasts, establishing the matrikine rationale. Robinson et al. (2005) conducted a double-blind, placebo-controlled, split-face study in which a topical formulation containing palmitoyl pentapeptide was applied to the face over several months and compared against vehicle for photoaging-related appearance measures, reporting improvements in some wrinkle and skin-roughness parameters.
These summaries report what the studies did and observed, in cell culture and in controlled cosmetic testing, and are not recommendations or guarantees of effect. Formulation details in the cited work belong to those studies.
Combinations examined in the research literature. Descriptive only — not a recommendation to combine compounds.