What are the benefits of peptides for the skin?

Peptides are small proteins, typically containing fewer than 100 amino acids. In terms of their I.N.C.I. nomenclature, Greek qualifying prefixes are used. For example, di-, tri-, tetra-, pentapeptides refer to peptides of 2, 3, 4 and 5 amino acids in length, and so on. There are several variations: acetyl tetrapeptide-15, hexapeptide-2, acetyl tetrapeptide-9, alanyl glutamine, acetyl tetrapeptide-11, acetyl hexapeptide-1, tetrapeptide-2, carnosine, cyclopeptide-5...

In skincare, peptides can be classified into four categories:

• The oligopeptides (or carrier peptides) provide trace elements to the skin to stimulate collagen.

• The enzyme inhibiting peptides slow down the action of enzymes that degrade certain skin proteins (collagen, elastin, filaggrin) or even glycosaminoglycans such as hyaluronic acid.

• The signalling peptides send messages to stimulate the production of certain proteins such as collagen, elastin, or even hyaluronic acid.

• The neurotransmitter peptides are often compared to "botox" due to their inhibitory activity on the release of toxins that induce muscle contraction and expression lines.

As a general rule, peptides act on various targets involved in supporting and enhancing skin density to limit skin ageing:

• Stimulate cellular proliferation.

  Certain peptides such as theacetyl tetrapeptide-11 increase cellular density, while also accelerating skin regeneration. The skin then gains in volume and the appearance of fine lines is diminished.

• Combatting oxidative stress.

  Other peptides such as the cyclopeptide-5 have a strong antioxidant activity. Thus, they inhibit the formation of free radicals, extremely reactive oxygen-derived species, which degrade healthy skin cells and proteins, accelerating its ageing.

• Stimulate the production of collagen and elastin.

  As a reminder, with age, the activity and number of fibroblasts decrease. This consequently leads to a reduction in the production of collagen and elastin, which are responsible for the firmness and elasticity of the skin. This then results in a skin laxity, a sagging of the skin and the appearance of wrinkles which, over the years, become more numerous and deeper. The peptides that boost the synthesis of collagen and elastin are the palmitoyl tripeptide-5, theacetyl tetrapeptide-9, the acetyl tetrapeptide-2, the tripeptide-10 citrulline or the Nicotiana Benthamiana Hexapeptide-40 Sh-Polypeptide-76.

• Maintaining skin hydration.

  Oligopeptides can penetrate cells and deliver minerals, such as calcium, manganese, and iron. This helps to promote collagen production in order to improve the skin's elasticity and hydration. Moreover, certain peptides stimulate the production of hyaluronic acid, resulting in hydrated, plump, and smoother skin.