La traduction cosmétique requiert une excellente compréhension du fonctionnement de la peau et des produits. Voici un glossaire bilingue des termes clés.

acide hyaluronique

hyaluronic acid

A naturally occurring moisturiser found in the dermis (deepest layer of skin) which regulates water content, elasticity and lubrication. Also found in the synovial fluid of the joints and the vitreous humour of the eyes it has exceptional hygroscopic (attracts water molecules) properties being capable of absorbing 1000 times its weight in water and holding water so tight that it forms a gel. A nonanimal form of hyaluronic acid is used in moisturisers due to its ability to form a thin film on the skin surface preventing moisture loss.



Naturally occurring acids found in various fruit and plants, hence the reason why they are sometimes referred to as “fruit acids”.  They are a milder form of the chemical peels used by cosmetic surgeons to remove the upper layer of the skin. Used in a variety of cosmetic preparations due to their exfoliating, hydrating, wrinkle reducing and photodamage correcting properties. Often shortened to AHAs.



Primarily a colouring agent obtained from the processing of edible fruits and vegetables. Responsible for the vibrant red and blue colours found in some fruits such as red grapes. It is also used to protect the skin and promote hair growth.



A substance which inhibits oxidation. Oxidation occurs naturally in the skin as we age producing free radicals. These free radicals then attack healthy cells in the skin the result of which is loss of skin elasticity and sagging. Antioxidants are therefore popular in anti-aging products because of their ability to counteract the activity of free radicals known as oxidative stress.



Tunnel shaped proteins found within cells allowing water transport across the cell membrane and through the cell. They are also known as water channels. Cosmetic companies are interested in identifying compounds which can stimulate these proteins to effectively regulate water content in the skin leading to better moisturised, more elastic skin.



An adjective meaning to constrict tissues. A term used in the cosmetics industry, sometimes also called a toner, to mean a substance which is considered to decrease the size of pores improving the appearance of the skin. However it is defined by the EU cosmetics unit merely as “contracts the skin”, and according to the American Medical Association there is no evidence that astringents can actually shrink or tighten the pores.

barrière hydrolipidique

hydrolipid barrier

The hydrolipid barrier, hydrolipid film or acid mantle refers to the skin’s balance of water (hydro) and oil (lipid). It is a thin emulsion of oil produced by the sebaceous glands and water produced by the sudoriferous (sweat) glands which coats the skin maintaining the correct pH level and moisture levels. An imbalance can cause dryness (lack of oil) or dehydration (lack of water). Many cosmetic products claim to reinforce the skins natural balance.



A term used in pharmacology to mean the rate at which or extent to which a drug is absorbed or becomes available at the target site in the body. Used in the cosmetics industry to refer to the amount of ingredient absorbed or made available at the action site in the skin once it is applied. This is important given that different products need to reach and act in different parts of the skin. A sunscreen for example needs to stay at the skin’s surface to protect against UV rays whereas melanin inhibitors (known as skin lighteners) need to penetrate both the stratum corneum (uppermost layer of the epidermis) and the epidermis (uppermost layer of the skin) in order to reach the melanosomes and inhibit the enzymes responsible for melanin production.



The stratum corneum is primarily made up of corneocytes which are completely flat, dead skin cells which gradually detach themselves from the skin and can also be removed through the use of chemical (such as AHAs) or abrasive exfoliants.

couche cornée

stratum corneum


corneum layer

The skin’s structure can be divided into three layers: the epidermis (upper layer), dermis (middle layer) and hypodermis (lower layer). The epidermis in turn is divided into five sublayers of cells, the stratum corneum being the uppermost layer. Composed of mainly dead cells which are constantly renewed, it also contains proteins called keratins which can absorb water and prevent moisture loss. This is the layer that we actually see, and therefore maintaining this layer in good condition is important to the appearance of the skin.



An emollient is a substance which creates a barrier on the skin surface to prevent moisture evaporation and therefore increase the skin’s moisture content.

facteurs naturels d’hydratation

natural moisturising factors

Natural Moisturising Factors or NMFs are a group of hygroscopic, hydrosoluable substances naturally found in the stratum corneum (surface layer of the skin) which keep the skin hydrated and in good condition. This complex of amino acids (the building blocks of protein) is artificially replicated and added to moisturisers.

glandes sébacées

sebaceous glands


oil glands

The sebaceous glands are located in the dermis and produce oil (called sebum) to prevent the skin from becoming dry. Overactive sebaceous glands, known as hyperseborrea, is a common condition in younger skin whereas the under production of oil, hyposeborrea, is a problem in older skin causing dry, thin skin which is prone to wrinkles. Dry skin refers to skin lacking oil, which should be distinguished from dehydrated skin which is a lack of moisture.

glandes sudoripares

sudoriferous glands


sweat glands

There are two types of sudoriferous glands called the eccrine and apocrine glands both located in the dermis.  

haute tolérance

high-tolerance (preferred industry term)



A product which is highly tolerated by the skin, i.e. containing ingredients considered unlikely to cause an adverse reaction in sensitive, reactive or allergy-prone skin.





Increasing the water content of the skin.





Hydrosoluble means able to dissolve in water.



An adjective describing an ingredient which is able to attract water molecules from the surrounding environment. Because of their capacity to absorb and retain moisture they are added to moisturisers to increase the skin moisture content. A substance which is hygroscopic is called a humectant.



An irritant is a substance which tends to cause local physical irritation, normally inflammation of the skin and painfulness. An irritant differs from a sensitiser or allergen in that it tends to cause irritation in all people whereas the ability of sensitisers or allergens to product a reaction depend on whether the individual has sensitive skin or an allergy.



A sensitiser is a sensitising ingredient, in other words an ingredient that can provoke a sensitivity reaction. A sensitiser should be distinguished from an allergen which causes allergenicity - a bodily reaction involving the entire immune system.



Sensitivity refers to a skin condition where the skin has an adverse reaction to a particular product such as inflammation, redness, itching, bumps, burning, etc. Ingredients that tend to cause sensitivity are fragrances and preservatives. Sensitive skin will react to the same ingredient in the same way every time it is applied, this distinguishes it from reactivity where skin which reacts differently to the same product each time.