Octapeptide-45 is a synthetic chain of eight amino acids. Unlike most cosmetic peptides, which aim at the extracellular matrix in the dermis, it is studied for effects in the epidermis, on barrier function and on inflammatory signalling.
A different target
Matrikines such as palmitoyl tripeptide-1 signal to fibroblasts to produce collagen. Neuropeptides such as acetyl hexapeptide-8 act at the neuromuscular junction. Both aim at depth.
Octapeptide-45 is proposed to act closer to the surface, on the processes that maintain the barrier and on the signalling involved in irritation and reactivity.
That has a practical implication: the delivery question that dogs most peptides is somewhat less pressing, since the target sits within the epidermis rather than in the dermis beneath it.
Where it appears
Almost always in products for sensitive, reactive or recently treated skin, and in hydrating rather than anti-ageing formulations. Its presence in an ingredient list is a reasonable signal about a product's intended use.
The evidence
Research comes from the ingredient manufacturer, which is the norm for cosmetic peptides, and independent replication is limited.
Octapeptide-45 is a relatively recent addition to formulation, and the body of evidence is correspondingly smaller than for the long-established peptides. It is a supporting ingredient rather than one carrying a formula.
In formulation
Water-soluble, stable, and used at very low concentrations. It carries no lipidating group, unlike the palmitoyl peptides, which is consistent with a target that does not require deep penetration.
