Skin: what it’s made of, how it works, and how to care for it

If you think of your skin as merely a surface to treat—or worse, an enemy to fight—it’s worth changing your perspective. Skin is a living, dynamic, intelligent organ: it changes over time, reacts to stimuli, and needs consistent care. It is what stands between you and the world, which is why it should be understood before it is treated.

In this guide, you’ll find everything you need to understand what skin is made of, how it works, and how to care for it: from its anatomical foundations to the pro-age philosophy.

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A complex organ, not a simple surface

Skin is the largest organ in the human body. It performs essential functions: mechanical and chemical protection, temperature regulation, hydration, sensory perception, and immune defense. It is not a static covering, but a tissue that renews itself, adapts, and communicates with the rest of the body.

Skin varies depending on the area: it is thicker on the hands and feet, finer on the face, and extremely thin around the eyes. That’s why every routine should account for these structural differences—and why a face cream is not suitable for the eye contour.

Not all skin is the same, and each skin type should be treated specifically. Having one skin type rather than another depends on genetics, lifestyle, and hormonal balance: we discuss this in the article on different skin types.

How it is made: the epidermis, dermis, and hypodermis

The epidermis: the protective barrier

The outermost layer is the epidermis. This is where the skin barrier is found—the structure that keeps water in and external agents out.

Imagine it as a wall: the bricks are the cells of the stratum corneum, while the mortar is a lipid matrix made up of ceramides, fatty acids, and cholesterol. When the barrier is intact, skin retains water effectively; when it is compromised, skin becomes dry, rough, and more sensitive.

The dermis: the supporting structure

Below the epidermis is the dermis, where the proteins that provide structure are found: collagen, which provides strength, and elastin, which allows skin to return to its original shape. This is also where hyaluronic acid is found, along with fibroblasts, the cells that produce all three of these substances.

The dermis also contains blood vessels and nerves. This is where loss of firmness develops when collagen and elastin production decreases: it is not a mistake, but a physiological process.

The hypodermis: the cushion

The deepest layer, composed mainly of fatty tissue, protects against impacts and pressure, serves as an energy reserve, and helps regulate temperature. Fat distribution changes over time and with hormonal fluctuations, contributing to the changes we observe in the face.

The functions of the skin

• Defense: protects against mechanical agents, chemicals, microorganisms, and UV rays. The skin microbiota lives on the surface and helps keep the barrier strong.
• Water balance: healthy skin keeps transepidermal water loss low. When the barrier is damaged, skin becomes dry and flaky.
• Thermoregulation: through vasodilation, vasoconstriction, and sweating.
• Sensory perception: receptors perceive touch, pressure, temperature, and pain. This is also why the sensory experience of a cosmetic is not a secondary detail: it influences how consistently we use it.
• pH balance: the acid mantle, with a pH between 4.5 and 5.5, inhibits the proliferation of pathogens.

The skin barrier: the starting point

If skin is a complex organ, the barrier is its starting point. A healthy barrier maintains hydration, reduces reactivity and sensitivity, and allows active ingredients to work more effectively without causing irritation.

That’s why every routine should begin by respecting the barrier: gentle cleansers, non-aggressive formulations, and supporting ingredients such as ceramides, physiological lipids, niacinamide, and hyaluronic acid. Caring for your skin does not simply mean adding active ingredients; above all, it means preserving what already works.

How it changes over time: the pro-age philosophy

Throughout life, collagen and elastin production decreases, hyaluronic acid levels decline, and fibroblasts become less active. These are physiological processes, not mistakes.

However, some factors accelerate them: unprotected sun exposure, pollution, stress, insufficient sleep, and overly harsh products. Cumulative UV damage, known as photoaging, causes more pronounced wrinkles, loss of firmness, and uneven skin tone.

Sun protection is the preventive measure supported by the strongest evidence: it blocks the cumulative damage that accelerates collagen loss and contributes to dark spots. It is not optional—it is the foundation of any pro-age routine.

Where anti-ageing treats wrinkles and dark spots as flaws to be eliminated, the pro-age approach accepts ageing as a natural process and supports it with realistic goals: maintaining the barrier and hydration, using active ingredients that improve skin quality, and adapting your routine to your age.

Skin during menopause

There is a time when skin changes particularly noticeably: menopause. Reduced oestrogen levels lead to lower collagen and elastin production, decreased hyaluronic acid, and drier, more reactive skin.

It is not anyone’s fault, but a physiological consequence. Skin does not become “wrong”: its characteristics change, and it requires different care. The goal is not to restore thirty-year-old skin, but to help it function well in its new phase—as we explain in the routine for skin over 50.

Neurocosmetics: the dialogue between skin and brain

There is a deep connection between the skin and the nervous system: both develop from the same embryonic layer. This dialogue is known as the brain-skin axis and forms the basis of neurocosmetics.

Under stress, the brain releases cortisol, which disrupts the barrier, increases sebum production, and makes skin more fragile. But the dialogue does not go in just one direction: the skin also communicates with the brain, which is the principle behind neurocosmetics.

How to choose products

Start with cleansing

A cleanser that is too harsh removes natural lipids and compromises the barrier. It is better to choose products with a pH close to the skin’s physiological pH, free from strong soaps and harsh sulphates.

One useful active ingredient during the renewal phase is mandelic acid, which exfoliates without disrupting the balance of the barrier.

Functional ingredients, not trendy ones

A functional ingredient has a clear mechanism of action, is supported by scientific literature, and acts on a specific function. Ceramides, hyaluronic acid, niacinamide, peptides, vitamin C, and urea all have a specific role. It is better to use a few well-researched, well-tolerated active ingredients.

Changing your routine too often makes it difficult to see the real effects and increases the risk of irritation. Keep your routine stable for at least 4–8 weeks, observe how your skin reacts, and make changes only if necessary. Consistency is more important than product perfection.

In conclusion

Understanding how skin is made and how it works is the first step towards caring for it consciously. There is no need to chase perfect skin: what matters is supporting its health, comfort, and function.

If you don’t know which skin type to start with, you can try our skin type quiz.