What do peptides do for the skin? A complete guide

Peptides have been used in dermatology for decades, but their use in daily skincare has grown in recent years for a specific reason: they allow formulas to work on firmness and wrinkles with a higher tolerance profile than other classic anti-ageing actives.

Unlike retinol or exfoliating acids, most cosmetic peptides do not accelerate cell renewal or create an initial adaptation process. They act as a signal, not as an irritant, making them useful even for sensitive skin or routines that already include more demanding active ingredients.

This combination — support for collagen synthesis and a low likelihood of irritation — is why brands such as Germaine de Capuccini position them as the basis of complete anti-wrinkle lines, rather than limiting them to a single specific product.

In simple terms, a peptide is a small fragment of a protein. When this chain is short enough, it has a greater chance of going beyond the skin surface and “communicating” with cells, something a whole collagen molecule, which is much larger, cannot do as easily.

This is why many creams and serums use peptides instead of pure collagen: the aim is not to “fill” the skin from the outside, but to help activate the mechanisms the skin already has to produce its own structural proteins.

In Germaine de Capuccini, this mechanism is at the heart of Timexpert Wrink·Less, the brand’s anti-wrinkle line, formulated with CELASPEP·4™, a patented biotechnological complex of biofermented ingredients and peptide fragments.

Peptides help the skin maintain its structure from within. Their main function is to act as a signal so that cells support the production of collagen, elastin and other support proteins, with visible benefits over time and with continued use.

They help improve firmness and elasticity, as they support the matrix that gives structure to the facial contour and help the skin recover better after a gesture or expression. They also help make expression lines look visibly smoother, because they work on the skin’s protein synthesis rather than simply offering a surface effect.

Some peptides also help reinforce the skin barrier, supporting the skin’s ability to retain hydration and protect itself against external aggressors such as pollution or changes in temperature. This is why they are recommended both in routines focused on loss of firmness and for skin that needs to reinforce its natural defence.

Not all peptides perform the same function. Before choosing a product, it is useful to understand which type of peptide it contains, because each family acts differently within the skin.

The two Expert Lab products mentioned in the table are delivered with HLG Nanopolymer™, the patented release system that helps the active reach its point of action more effectively. The nanopolymer does not provide efficacy on its own: its function is to act as a delivery system, and the result depends on the peptide it carries in each case.

All three ingredients work on wrinkles and firmness, but from different angles. Topical collagen hydrates and forms a protective film on the surface, although its molecule is too large to penetrate and support collagen production on its own. Peptides, being smaller fragments, can help support this production from within. Retinol works more intensively by accelerating cell renewal, and often shows visible changes earlier than peptides, but with a higher possibility of irritation in sensitive skin.

In practice, you do not need to choose only one. Many anti-ageing routines combine peptides in the morning with a renewal product, such as retinol, in the evening, always with daily sun protection.

The first thing to assess is the type of peptide and the rest of the formula, not just the presence of the words “with peptides” on the label. A cream with signal peptides and hyaluronic acid, for example, can work well for mature skin looking for firmness without giving up hydration.

Peptides are applied after cleansing and toner, in serum format if the skin needs a higher concentration, or directly in a treatment cream if a simpler routine is preferred. In the morning, it is advisable for a peptide cream to include SPF or be completed with sun protection; in the evening, it can be applied as the final step before going to sleep.

They combine well with niacinamide, which reinforces the skin barrier, and with vitamins C and E, which provide antioxidant protection. It is preferable to avoid combining them with very strong exfoliants in the same routine, as this may increase the risk of irritation and reduce the overall effectiveness of the actives.

Although peptides are generally well tolerated from younger ages, they are often introduced preventively from around the age of 30, when the skin naturally starts producing less collagen and elastin.

The format matters as much as the ingredient. A serum concentrates more peptide in less product and penetrates more quickly, so it is more suitable when the priority is treating visible expression lines. A peptide cream, on the other hand, distributes the active together with a higher amount of emollients, making it more suitable for dry skin or when the aim is to support daily results without adding too many steps.

In mature or very dehydrated skin, combining both formats — a peptide serum under a cream with hyaluronic acid — can offer a more complete result than using just one product. In younger skin looking only for prevention, introducing a peptide cream as the treatment step may be enough, without immediately adding a serum.

For sensitive or reactive skin, it is advisable to introduce peptides progressively, first a few evenings per week and then increasing frequency up to daily use, especially if other active ingredients are already present in the routine.

The Timexpert Wrink·Less line by Germaine de Capuccini is formulated with CELASPEP·4™ to help work on firmness and expression lines with continued use.

In the morning, the Pro-Collagen Serum is applied after cleansing to concentrate the peptide in the areas of greatest expression, followed by the Pro-Collagen Day Cream SPF30, which adds sun protection to the routine.

In the evening, the Pro-Collagen Cream reinforces the work of the serum while the skin regenerates, while the Pro-Collagen for Eyes and Lips cares for the areas where skin is thinner and expression lines tend to appear earlier.

The order of application is important: more fluid products, such as serum, should always be applied before richer products, such as cream, so that the peptide does not need to cross a layer of emollients before reaching the skin. Maintaining this order for several consecutive weeks is what allows the cumulative effect of peptides to become more evident, both in terms of firmness and the depth of expression lines.

For those looking for targeted reinforcement, Expert Lab offers two complements: Collagen Peptide, with collagen peptides, and Growth Factor, with the plant-origin oligopeptide mentioned in the table above.

For those who want to accompany their at-home routine with an in-salon service, Germaine de Capuccini also offers the Timexpert Wrink·Less professional treatment, designed to reinforce the same mechanism with higher-concentration actives.

Peptides work best when they are part of a routine designed to address expression lines as a whole, rather than as a single isolated product. Combining them with hydration — you can learn more about the role of hyaluronic acid — and daily SPF is what supports medium- and long-term results.

If your priority is firmness and expression lines, Timexpert Wrink·Less with CELASPEP·4™ is the most direct starting point in the Germaine de Capuccini catalogue. If you want to reinforce a specific area, such as the eye contour, or work on uneven texture, the Expert Lab complements can work as an extra step within the same routine, without replacing it.

As with any active ingredient, the skin needs time to show the work of peptides. Assessing the result after only a few applications may lead you to change product too soon, when the collagen synthesis process has only just begun.