Skincare glossary I-Z

From inflammatory reactions to mucous membranes and keratin, here is the final part of our glossary on cosmetics and skincare. To become an expert on what keeps your epidermis healthy, check out the previous two sections here and here.

Inflammation

When tissue such as the skin is attacked, it tries to protect itself. It becomes red, heats up, and may even swell, forming an edema or becoming painful. If inflammation appears in a joint, mobility may be affected. This is a completely normal response. It is triggered by our immune system, which activates its defense and repair mechanisms in case of intrusion by viruses, bacteria, or injuries.

Some inflammatory skin reactions are mild and can be soothed by applying cold. Others, more intense, may require the use of anti-inflammatory medications (always under the advice of a healthcare professional!).

INCI

The way the composition of a cosmetic product is described follows an international standard known as INCI (International Nomenclature of Cosmetic Ingredients).

Ingredients are listed in descending order of concentration. Plant extracts (floral waters or vegetable oils) are labeled with their Latin names, while molecules and common names are given in English.

Everywhere in the world, regardless of the cosmetic products you use, you can know their composition and identify potential allergens or other substances you may wish to avoid.

Keratin

Keratin is a fibrous protein that makes up 95% of our hair, nails, and body hair. During the skin renewal process carried out by keratinocytes, the cells become loaded with keratin and flatten into scales as they move toward the outer layer to die. This process is essential for maintaining the structure and resilience of the skin.

Keratin is insoluble in water, contributing to the waterproof nature of the upper layers of the epidermis.

Repeated friction can accelerate keratin production and lead to the accumulation of dead cells on the skin’s surface. This is how calluses form on runners' feet or climbers' hands.

Extracellular Matrix

The extracellular matrix (ECM) is composed of collagen, elastin, proteoglycans, and structural glycoproteins. It supports the cells within tissues. More than just a scaffold, it stores all the signals necessary for proper cellular regeneration processes.

ECMs are primarily synthesized during childhood. As we age, we produce less of them, and they degrade more quickly. As a result, cellular regeneration and skin repair processes may become less efficient.

The specificity of RGTA, the patented technology at the heart of RGENTec products, is that it rebuilds the extracellular matrix, optimizing tissue restoration so they regain their original function and structure.

Melanin

The color of our skin, hair, body hair, and eyes is due to melanin. Its role? To protect us from ultraviolet rays, which cause sunburn and can also lead to DNA damage, phototoxic reactions, photoallergies, and immunosuppression, recognized by the World Health Organization as a cancer risk factor. This is why its production increases after sun exposure.

The level of melanin determines the phototype, which classifies skin types based on their complexion and how they react to UV rays.

• PHOTOTYPE I: Very fair skin, red hair, freckles. Does not tan, always burns.

• PHOTOTYPE II: Very fair skin, blonde to light brown hair. Tans very little, burns often.

• PHOTOTYPE III: Fair skin, blonde to brown hair. Tans gradually, sometimes burns.

• PHOTOTYPE IV: Olive skin, brown or dark hair and eyes. Tans easily, rarely burns.

• PHOTOTYPE V: Dark skin, brown or black eyes. Tans very easily, rarely burns.

• PHOTOTYPE VI: Very dark to black skin. Never burns.

Cutaneous Microcirculation

The hypodermis and dermis, the two deepest layers of the skin, are richly vascularized thanks to a lymphatic and blood network composed of capillaries, venules, and arterioles. The epidermis, however, absorbs the nutrients it needs by diffusion from dermal papillae and capillary networks.

This cutaneous microcirculation plays a crucial role: it contributes to the nourishment of cells in all layers of the skin and nails. It participates in the body’s thermoregulation. It helps maintain blood pressure. Finally, it allows the skin to compensate for blood supply deficiencies caused by body weight.

Mucous Membrane

Mucous membranes are made up of a set of closely packed cells (epithelium), a basal membrane, and a vascularized layer (the chorion). Mucous membranes line the inside of our mouths, respiratory and genital tracts, and digestive system. They play a protective mechanical, chemical, and biological role similar to that of the skin.

With an additional function: by producing mucus, they provide an extra defense while lubricating and moisturizing the organs.

Nourishing

In cosmetics, the terms "nourishing" and "hydrating" are often used interchangeably. However, nourishing and hydrating treatments do not serve the same function!

A so-called nourishing treatment generally has a richer, more emollient texture. It helps the skin restore and maintain its hydrolipidic film. Nutrient-rich skincare compensates for low sebum production and soothes skin that feels tight, reddens, or flakes. This is the case with Bye Bye Burn balm, for example.

Pore

The epidermis is made up of countless tiny openings: pores. They facilitate exchanges between skin cells and the external environment, promoting oxygenation. Sweat pores eliminate perspiration and dead skin cells. Sebaceous pores distribute sebum across the skin’s surface. When you apply a skincare product to your epidermis, its active ingredients are absorbed through the pores.

Cell Renewal

Epidermal cells are in a constant state of renewal. Keratinocytes are born in the deepest layer of the epidermis, the basal layer. They gradually move to the surface, flattening out before dying in the outermost layer. This cycle lasts 28 days. It occurs naturally in healthy skin. However,when the skin is damaged, the healing process takes over.

Serum

In cosmetics, a serum is a product with a lighter, more watery texture than a conventional cream. Like After Sport Ritual, serums are rich in active ingredients (such as hyaluronic acid and the RGTA complex) and act deeply within the skin.

Sweat

Sweating helps regulate body temperature, preventing it from exceeding 37°C (98.6°F). Sweat is composed of water, electrolytes, as well as urea, ammonia, and lactic acid.

Contrary to popular belief, sweat does not "purify" the body. While engaging in activities that induce sweating can be beneficial, they do not significantly eliminate toxins. Or at least, very few. But that’s no reason to stop exercising, given its numerous benefits—especially for the skin!