My skin is labeled DE(-); what does this designation mean?

Cutaneous aging: BEGINNER ("Débutant" in French)

Oxidation factors: EXPOSED

Sebum production: LOW (-)

The letter “D” indicates that the skin has entered the initial visible phases of cutaneous aging. Expression lines appear when the skin moves—especially around the eyes and mouth—and represent the earliest detectable signs of tissue laxity. These fine lines are often accompanied by altered skin texture, a less even complexion, and a gradual decline in radiance. Together, these manifestations mark the first biological slowdowns within the various layers of the skin, typically observable by the late twenties.

From that age onward, the production of collagen, an essential protein for dermal cohesion and firmness, declines by approximately 1% per year. This gradual decrease disrupts the extracellular matrix and weakens connective tissue density. Simultaneously, epidermal cell renewal slows, disrupting the barrier function, increases transepidermal water loss, thereby accentuating fine lines. Finally, the synthesis of hyaluronic acid, a molecule naturally present in the skin that can retain up to 1,000 times its weight in water, decreases by an average of 6% per decade, contributing to the loss of skin suppleness and bounce.

The aging process in DE(-) skin remains superficial and mainly functional: the skin still retains a strong capacity for recovery. However, implementing a tailored skincare routine can slow this transitional phase and help maintain the skin’s youthfulness over time.

The “E” indicates that the skin is highly exposed to external aggressors (solar radiation, air pollution, tobacco, stress, alcohol...), and that its sun protection habits are insufficient relative to its phototype and its exposure pattern. These oxidative factors promote the production of free radicals, highly unstable and reactive molecules that can have a lasting impact on the skin. Note that free radical production is a normal process in all oxygen-consuming living organisms. They possess an endogenous antioxidant defense system that helps keep the amount of free radicals generated under control.

However, when there is an imbalance between the production of free radicals and the body’s ability to neutralize them, a situation of oxidative stress sets in and skin damage can occur. Indeed, free radicals are reactive species that contribute to the degeneration of skin cells in both the epidermis and the dermis. All vital skin components—such as collagen, hyaluronic acid, elastin, lipids, and DNA—are attacked, resulting in various dysfunctions. This oxidation process can affect the structure of the skin, accelerate its aging, and even heighten the risk of cancer. Wrinkles - first superficial and then increasingly deep - loss of firmness, and a duller complexion can begin to appear, and this can happen prematurely.

The "-" indicates a reduced efficiency of the sebaceous glands in producing enough sebum to protect the skin, as well as an abnormality in the synthesis of natural moisturizing factors by keratinocytes. These hygroscopic molecules (amino acids, lactates, urea, mineral ions...) normally ensure water retention within the stratum corneum. Tightness, irritation, fine dehydration lines, redness, flaking, dull complexion... are characteristic of this skin type.

Indeed, this lack of fatty substances reduces the effectiveness of the hydrolipidic film and increases water loss. This alteration of the skin barrier can also disrupt the activity of Langerhans cells, the epidermal immune sentinel cells, sometimes triggering an excessive inflammatory response to stimuli normally harmless. Several factors can influence the low sebum secretion in DE(-) skin, such as frequent washing, certain medications, unsuitable skincare, seasonal variations, smoking, UV radiation, or genetics.

DE(-) skin presents two vulnerabilities: high exposure to oxidative factors and insufficient sebum production. To address these weaknesses, we recommend the following skincare routine.

In the morning, the priority is to prepare the skin to face external aggressors while providing it with hydration and nutrition. After a gentle cleanse, for example with a toning lotion, we recommend that DE(-) skin types use an antioxidant serum. Active ingredients such as vitamin C, resveratrol, or ferulic acid help to neutralize free radicals generated by pollution and UV radiation. Next, to restore the hydrolipidic film, it is important to use an emollient cream containing, for example, squalane, naturally present in sebum, or ceramides, found in the stratum corneum. These physiological lipids help restore the skin barrier and reduce transepidermal water loss. Finally, don’t forget sunscreen, even on cloudy days, to reduce oxidative stress induced by UVA and UVB rays.

In the evening, the skin enters a phase of active cellular regeneration : this is the time to supply it with reparative and relipidating active ingredients. After a gentle cleanse, for example with a superfatted soap or a cleansing balm, applying a hydrating serum based on hyaluronic acid promotes water retention in the stratum corneum. You can then follow up with a relipidating serum formulated from squalane or a biomimetic complex, to strengthen the skin barrier and soothe sensations of tightness. Finally, to lock in hydration and nourish the epidermis over time, simply apply a rich-textured moisturizing cream.