Everything you need to know about peptides in cosmetics.

The primary role of exogenous peptides is to effect changes in the complex pathways regulating the expression of skin proteins, generally to prevent signs of ageing. In other words, peptides are most often used to trigger a signalling cascade and stimulate the production of collagen and elastin. These fibrous proteins present in the dermis ensure flexibility and firmness to the skin, but their content in the skin tends to decrease over the years. Moreover, certain peptides can also boost the production of hyaluronic acid in the skin, for a hydrated, plump and smoother skin.

In relation to the I.N.C.I. nomenclature, Greek qualifying prefixes are used. For instance, di-, tri-, tetra-, pentapeptides refer to peptides of 2, 3, 4, and 5 amino acids in length, and so forth. There are numerous variations: tetrapeptide-2, acetyl tetrapeptide-15, hexapeptide-2, acetyl tetrapeptide-9, alanyl glutamine, acetyl hexapeptide-1, carnosine, acetyl tetrapeptide-11, cyclopeptide-5, and so on...

Note : Peptides can have functions beyond their role in reducing the appearance of wrinkles. They can influence various biological processes in the skin such as inflammation, cell proliferation, melanogenesis, oxidative stress... When applied to hair follicles, certain peptides offer densifying properties. They stimulate, strengthen and densify the cells of eyelashes and eyebrows, while helping to keep them healthy.

• The oligopeptides provide trace elements to the skin to stimulate collagen production.

• The enzyme inhibiting peptides slow down the action of enzymes that degrade certain skin proteins such as collagen or glycosaminoglycans like hyaluronic acid.

• The signal peptides send messages to stimulate the production of certain proteins such as collagen, elastin, and 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.

Peptides are often identical or analogous to protein fragments already present in the body, which significantly reduces the risk of side effects. There are no contraindications to topical use of skincare products containing peptides; pregnant and/or breastfeeding women can use them. Furthermore, peptides are generally introduced into cosmetic formulas in very small quantities (which does not limit their biological actions in any way).

We have included pea peptides (INCI name: "Pisum Sativum (Pea) Peptide) in the following two treatments: the scalp serum densifying with 2% peptides and ginger extract (INCI name: "Zingiber Officinale (Ginger) Root Extract"), and the eyelash & eyebrow serum formulated with 2% pea peptides and castor oil (INCI name: "Ricinus Communis (Castor) Seed Oil"). The pea peptides are rich in phytonutrients, particularly in isoflavones. They stimulate, in the dermal papilla, specific molecules essential for reactivating the growth of hair, but also other types of hair such as eyelashes and eyebrows.

Furthermore, the density & firmness serum combines three peptides: cyclopeptide-5 (INCI name: "Cyclotetrapeptide-24 Aminocyclohexane Carboxylate"), acetyl tetrapeptide-11 and acetyl tetrapeptide-9. The 3 peptides present in this serum work simultaneously on different targets involved in the support and density of the skin. Acetyl tetrapeptide-9 acts on the lumican protein to strengthen the skin's structure. Acetyl tetrapeptide-11 acts on a protein present on the skin's surface to smooth it. The cyclo tetrapeptide-24 is an antioxidant and helps to combat free radicals.

The hyperpigmentation and firmness serum combines tranexamic acid at a high concentration (5%) with acetyl tetrapeptide-2, a multi-functional peptide, to reduce the appearance of pigmentation spots and firm the skin. The tetrapeptide-2 stimulates the synthesis of key molecules involved in skin support and firmness: elastin, collagen, and fibrillin. It also inhibits certain reactions in the melanogenesis process, thus reducing brown spots. Finally, it has a strong antioxidant power that protects the skin against free radicals and revives its natural glow.

Finally, ourwrinkle and blemish serum combines the densifying action of retinol (0.3%) with the anti-bacterial action of bakuchiol (1%) to reduce the appearance of wrinkles and correct blemishes. Synthesised by endemic Australian plants, it also containsplant-based polypeptides capable of working in synergy with retinol to promote the synthesis of type I collagen. They thus help to reduce the depth of wrinkles and densify the skin.