Cosmetics and skin absorption

We have all wondered at some point whether cosmetic products penetrate our skin and how deeply. And if they do, are they dangerous?

The most basic of all in the science of how a cosmetic acts is transdermal absorption. Our skin is not a sponge! It cannot absorb everything that is on it. Besides, if it did, we would have repeated infections. On the contrary, it is an almost impenetrable sentinel that prevents the passage of harmful substances. An impenetrable, impermeable shield with a wisely formed triple "control" system.

The first is the acid mantle a natural film with a slightly acidic pH composed of sebum, water and sweat that covers the keratin layer of the skin. Its role is to prevent the passage of dangerous substances. The second and strongest barrier is the keratin layer which resembles a cluster of bricks. In between is an intermediate watering substance (NMF) that acts as a cement! The third, thinner but very strongest barrier is the basement membrane that separates the stratum corneum from the horny layer and which, among other things, acts as a selective filter.

Cosmetic ingredients, however, have their way. Cosmetology is well aware that a substance needs to travel quite a long distance and overcome many obstacles to reach its target. It is equally well aware of the factors that will allow the active ingredients of a cosmetic product to penetrate and drive them to where they need to be in order to deliver the effect they promise.

How long a cosmetic ultimately lasts depends on:

1. 1. The molecular weight of the active ingredient is the main factor that allows or prevents the penetration of a substance. Large molecules are almost impossible to penetrate the 'wall' of dead keratinocytes. This is of course not necessarily a bad thing, as we need nutrients on the surface of the skin as well. A typical example is high molecular weight hyaluronic acid, which remains on the surface of the skin and moisturizes it, while small molecular weight hyaluronic acid fractions penetrate the skin and "fill" wrinkles from the inside.

2. The hydrophilic, lipophilic or amphiphilic nature of the substance is an additional factor that determines its ease of penetration. Lipophilic or amphiphilic ingredients 'slip out' more easily, thanks to their biocompatibility with the lipids of the intercellular space, the 'cement' of the cells mentioned above. Hydrophilic components have more difficulty. Let's not forget, we said that the skin is waterproof!

3. The thickness or condition of the skin, finally play a decisive role. In areas where the thickness of the skin is small, such as the area around the eyes, the ingredients penetrate more easily. This is, moreover, one of the reasons why certain active facial formulations are recommended not to be applied to the skin around the eyes. On the other hand, the disturbed epidermal barrier in a skin that is damaged, dehydrated or simply after intense exfoliation, facilitates the penetration of active ingredients, but at the same time also the 'invasion' of harmful substances.

What if they get through? Can they harm us?

No, cosmetic ingredients do not harm our health. The skin does not absorb everything that we touch or apply to it, and what passes through does not reach a point where it can harm us. Besides, if that were the case, all medicines would be topical rather than systemic. And even if some of them did pass into the bloodstream, the natural filtering system would have no difficulty in eliminating them. Of course all this does not mean that an improper choice or use of cosmetic preparations cannot harm our skin.

Skin4sin's cosmetic product research and development departments, before giving the green light for the production of a new formula, evaluate the active ingredients both in terms of their penetration into the skin and their action. Skin4sin has selected for you safe cosmetics with herbal active ingredients with multiple penetration and action for all skin types. Our estheticians are here to help you find what you really need.