Tetrapeptide-30

Tetrapeptide-30 is a synthetic chain of four amino acids, and it is unusual among cosmetic peptides for addressing pigmentation rather than structure.

Why that is unusual

Almost every peptide used in skincare aims at the extracellular matrix: signalling fibroblasts to produce collagen, interfering with matrix breakdown, or supporting structural proteins. Matrikines, neuropeptides and carrier peptides all sit in that territory.

Tetrapeptide-30 is studied for effects on melanin production instead, with proposed activity on tyrosinase, the enzyme that initiates melanin synthesis.

Why a peptide for pigmentation

The conventional tyrosinase inhibitors, kojic acid, arbutin, hydroquinone, share a broad structural similarity and a similar mechanism. Several also carry irritation or sensitisation considerations.

A peptide approaching the same target from a different structural direction is potentially useful, particularly for skin that does not tolerate the usual options, or for areas like the under-eye where irritation is poorly tolerated.

The evidence

Research comes from the ingredient manufacturer, which is the norm for cosmetic peptides. Independent replication is limited, and the body of evidence is considerably smaller than for niacinamide, vitamin C or tranexamic acid.

This is a supporting ingredient in a pigmentation formula rather than the ingredient carrying it.

Delivery

The usual peptide question. Tetrapeptide-30 is small, which helps. Melanocytes sit at the base of the epidermis, so the target is not as deep as the dermal fibroblasts most peptides aim at, which also helps. Neither settles the matter.

In formulation

Used at very low concentrations, water-soluble, stable, and typically combined with other pigmentation ingredients working through different routes rather than used alone.