Skincare glossary E-H

The Language of Skin: Discover the next section of our glossary to master the vocabulary of skincare—essential concepts to better understand the functioning of the largest organ in our body and navigate the world of cosmetics with ease.

A closer look at skincare terminology, from E for Elasticity to H for Hypodermis!

To explore key concepts from A to D, click here!

And for I to Z, it’s here!

Elasticity

Elasticity is one of the signs of a healthy epidermis. Healthy skin should be flexible, allowing it to stretch and contract without tearing or damage. Elastin and collagen, found in the dermis, provide the skin with this fundamental property. Less supple skin can be more fragile. While various factors like aging or hormones can cause a loss of elasticity, a well-adapted skincare routine and a healthy lifestyle can help maintain or restore your skin’s elasticity.

Elastin

Elastin is a protein that complements the functions of collagen. Secreted by fibroblasts (cells that maintain dermal cohesion), elastin enables the skin to return to its original shape after being pinched or stretched. This protein is not only found in the skin but is also an essential component of arteries, lungs, the bladder, cartilage, and ligaments. However, while our body continues to synthesize collagen throughout life (albeit in decreasing amounts), we stop producing elastin at the end of puberty.

Emollient

From the Latin emollire (to soften), an emollient is a product or texture designed to relax or soften biological tissues. In cosmetics, an emollient product typically has a lipid-rich, oily texture intended to nourish the skin. Its function differs from that of a humectant (such as glycerin or hyaluronic acid), which aims to provide maximum hydration to the epidermis.

Epidermis

The epidermis is the outermost layer of the skin. Its thickness varies depending on the body area, ranging from 0.3 millimeters on the eyelids to 6 millimeters on the soles of the feet and palms. Its surface is primarily composed of keratinocytes, cells that constantly renew and migrate from the basal membrane (which separates it from the dermis) to the surface. The stratum corneum, its outermost part, is relatively impermeable when healthy, helping protect our body from external aggressions, including shocks, viruses, microbes, and bacteria.

Just beneath the stratum corneum are melanocytes, which produce melanin. These pigments determine our skin color and protect us from ultraviolet rays.

Fibroblast

Fibroblasts are the primary cells that make up our connective tissues, including the skin. With their star-like shape, fibroblasts synthesize components of the extracellular matrix, such as hyaluronic acid, elastin, and type I and III collagen. They play a crucial role in skin regeneration and wound healing.

Hydrolipidic Film

The hydrolipidic film consists mainly of secretions such as sebum and sweat. This water-in-oil emulsion works alongside the stratum corneum to create a protective barrier. It helps fight off harmful microbial aggressions while ensuring optimal skin hydration.

The quality and effectiveness of the hydrolipidic film vary depending on multiple factors, including age, hormonal balance, environmental conditions (pollution, temperature), and overall health. Again, an appropriate skincare routine can help preserve, enhance, or restore this natural barrier.

Filter (Chemical or Mineral)

Approximately 80% of skin cancers are linked to sun exposure. Protecting your skin from harmful radiation is essential, requiring simple but effective habits. To shield against UVA and UVB rays, cosmetics offer two types of filters:

Organic or chemical filters, which absorb UV radiation.

Mineral filters (usually titanium dioxide or zinc oxide), which reflect UV rays.

Most sunscreens combine both types of filters. To ensure clarity regarding their effectiveness, they are classified by their Sun Protection Factor (SPF). Depending on your skin type and sun exposure conditions, it is advisable to use a sunscreen with at least SPF 30, reapplying it regularly, especially when engaging in outdoor sports.

Hair Follicle

A hair follicle is a bottle-shaped structure where hair grows. Found almost everywhere on the body except the palms, soles, and lips, hair follicles assemble cells to produce hair through keratinization. These follicles are often connected to sebaceous glands, which produce sebum—a key component of the hydrolipidic film that lubricates hair and skin.

Galenic Forms

The galenic form refers to the physical state in which active ingredients are delivered in a cosmetic product. There are three main types:

Dispersions – Emulsions (moisturizing creams, cleansing milks), foams, aerosols (thermal water, deodorants), suspensions (nail polish, foundation). Anhydrous Forms – Balms, powders (eyeshadow), oils, ointments. Aqueous Forms – Gels, colloidal solutions (serums, micellar water), true solutions (lotions, floral waters).

Humectant

A humectant attracts and retains water on the skin’s surface to maintain hydration. Some humectants, like hyaluronic acid, are naturally present in our body. Unfortunately, they are not always sufficient to keep the skin supple, particularly when it needs to heal or regenerate after external stress. That’s why humectants are essential allies in your skincare routine.

The most commonly used humectants in cosmetics include glycerin, hyaluronic acid, and urea.

Moisturizer

Our skin is composed of 67% to 73% water. The closer you get to the skin’s surface, the lower the water content (a well-hydrated stratum corneum contains 15% to 20% water). One of the epidermis’s key roles is to help maintain water balance, minimizing moisture loss.

By moisturizing the epidermis, we help it retain water, making it more resistant, supple, comfortable, and healthier. Well-hydrated skin can better withstand external aggressions, heal more effectively, and age more slowly.

In cosmetics, moisturizers come in gels, creams, or serums. These contain water and active ingredients that remain on the surface to prevent water evaporation, as well as humectants that act as water reservoirs.

Hypodermis

The hypodermis, also known as the subcutaneous white adipose tissue, is the deepest layer of the skin. Located just below the dermis, it is richly vascularized. It plays a key role in energy storage and release, as it stores and releases lipids according to the body’s needs.

Additionally, the hypodermis serves as a thermal regulator, helping to protect muscles, bones, and organs from shocks.