In the 90s, cosmetics swore by “two in one”, very practical multifunction formulas. “But, with the wave of layering (superposition of several products) coming from Asia, the labs have abandoned these all-purpose treatments, supposed to be suitable for all skin types, remarks Aurélie Guyoux, Scientific Director of State Pur. We now prefer the “one to one”, personalized and hyper-targeted. Especially since each skin is different and its needs change with the seasons, but also with our way of life, our environment, our eating habits, our degree of stress or from fatigue… ”Hence the appearance of these ultra-concentrated“ boosters ”, capable of responding to a specific problem: redness, fine lines, spots, dark circles, Pores, Dull complexion… as precisely as possible.

A diagnosis to identify the needs of the epidermis

In order to find the right dosage, it all starts with an accurate diagnosis. “No need for a magnifying mirror, or a diploma in cosmetics, warns Aurélie Guyoux. You just have to take a good look at your skin and understand what it is expressing. Is it firm or a little wrinkled? Plump to the touch? Does it capture light well? Is she getting dehydrated faster than usual? Does it have small pimples, spots? To help us answer all these questions, most brands today offer diagnostics, to be done in store or online: nature of the epidermis, lifestyle, environment, concerns (wrinkles, eye contour, imperfections, loss of radiance or firmness …). Our “daily skin” is scrutinized to define, in a few clicks, a tailor-made protocol. We therefore leave with a beauty prescription and the corresponding product (s). This essential diagnosis must be renewed regularly, every 3 months for example, to stay as close as possible to the needs of your skin.

A hyper-targeted and effective composition

Unlike a serum often combining several types of active ingredients (moisturizers, firming agents, etc.), boosters only contain two or three molecules from the same family. Beyond that, the skin saturates and does not assimilate them correctly. “This type of formulation allows the active ingredients to be more effective,” emphasizes our expert. Thus, salicylic acid must be concentrated to 2% for a perfect purifying action. But, in a classic cream, it is rarely offered at this dose. And the other ingredients often interfere. Another example : resveratrol. It is one of the best antioxidants on the market, but it is difficult to stabilize. ”

Pure and very concentrated, the boosters take effect in just a few applications. While the effect of a serum is only visible after a cycle of cell renewal, or 28 days. Thus, with a “detox” booster rich in green coffee, the radiance resurfaces very quickly. With another, concentrated in zinc, the complexion becomes more matte over the days. The formulas rich in glycolic acid offer an immediate peeling effect, those based on arginine visibly reduce dark circles and puffiness, those containing ficaria extract soothe redness in no time …

A personalized user manual that makes all the difference

On the application side, several options are possible depending on the brand. But, whatever happens, these boosters concentrated in pure active ingredients can be combined with another treatment and never used alone. Most (Clarins, Sephora, Dr. Brandt) can be mixed in the palm of your hand with a rather basic moisturizer, in order to avoid interactions with too many active ingredients, just before use. Or a hydrating mask for a more intense action. Others (Kiehl’s or Dr Pierre Ricaud) propose to incorporate their boosters in a neutral base, responsible for sufficiently moisturizing the skin. The preparation is therefore done here in one go. Still others (like Etat Pur) rely on an application directly on the skin, before applying their day cream. “One or two well-targeted drops, only on the area to be treated, make it possible to act in the right place thanks to a vectorization system,” indicates Aurélie Guyoux. To attenuate the spots, the depigmenting active ingredients must thus reach the melanocyte at the base of the epidermis. To restore softness to the skin, hyaluronic acid will target the fibroblast, more in depth. »To be used as a single dose or as a treatment of 1 week to 1 month, depending on the condition of the skin. And especially to the changes of season (at the start of the school year, for example) and during peaks of pollution or any other phenomenon that could unbalance the epidermis.

For our hair too …

To extend the benefits of a salon treatment, Kérastase has just launched its tailor-made box: four concentrates (dry, colored, damaged or refined hair) and five boosters (shine, density, discipline, reconstruction or nutrition), to be determined with the hairdresser- expert in salon. It corresponds to 1 month of home care.

It gently cleanses

Thanks to mild surfactants: more and more often, non-ionics, sugar-based (decyl-glucoside, lauryl-glucoside, coco-glucoside, etc.) or derivatives of fatty alcohols, derived from coconut oils or palm, or a mixture of the two (sodium cocoyl taurate, sodium cocoyl glutamate).

The advantage: they do not attack the skin and clean it quite well, and they also foam very little.

She does not dehydrate

Because it contains at least one highly hydrating ingredient, glycerin. And, for some, also hyaluronic acid and soothing active ingredients derived from plants (rose, cornflower) and nourishing (honey, cottonseed oil) … In addition, their surfactants are not strippers, and are integrated into the just dose.

She respects the skin

For an effective cleansing action that respects the skin’s balance, the surfactants are organized into micelles. These spherical molecules are made up of two parts of different polarity: one, lipophilic, in strong affinity with fats; the other, hydrophilic, in affinity with water. The first (lipophilic) have the capacity to grip the dirt and trap it, while the second, in affinity with water, entrain this dirt during rinsing.

It protects against pollution

First, because it rids the skin of particles that accumulate there thanks to its cleaning power. But also, because it contains active antioxidants which protect against environmental attacks and free radicals.

In practice

How to choose it? When you like cleaning with water, you have to choose your foam according to your skin type and when you use it.

– In the morning in the shower, opt for a gentle or organic cleansing foam, for sensitive skin, or with AHAs (fruit acids) if you want more radiance.

– In the evening, prefer a foam with make-up removing power, with active “care” which help to quickly reconstitute the skin barrier.

Can we remove make-up from the eyes?

Not always ! If the foam contains too strong surfactants or fruit acids intended for a light exfoliation, it is better to avoid the eye area, which is highly sensitive.