Complete guide to exfoliation: acids for every skin type

Exfoliation has become one of the most controversial steps in skincare. For years we've oscillated between extremes: from the obsession with daily exfoliation to completely avoiding it out of fear of damaging the skin barrier. Dr. Shereene Idriss, a board-certified dermatologist, helps us find the perfect balance.

The reality is that we need to exfoliate because we produce between 20,000 and 40,000 dead skin cells daily. These cells, along with makeup, creams and environmental pollution, accumulate on our skin's surface, creating a layer that can make us look dull and lifeless.

Why exfoliation is essential

Our natural cell cycle brings cells from the deeper layers to the surface in 10 to 28 days when we're young. However, this process slows down with age: 30 days at age 30, 40 days at age 40, and so on. This slowdown is what makes us look less radiant and with irregular texture.

Exfoliation helps accelerate this natural process, revealing younger cells and allowing our skincare products to work better. It's not that products work 100 times better, but any improvement we can get is worthwhile.

The three types of exfoliation

There are three main categories of exfoliation, each with specific characteristics:

Physical exfoliation: Includes scrubs, sponges and abrasive tools. While they can be useful for the body, they are not recommended for the face because they can create micro-lesions and irritation. Reserve these methods for professionals or use them only on thicker body skin.

Enzymatic exfoliation: Derived from fruits like papaya, pineapple and pumpkin, it gently dissolves the connections between dead cells. It's ideal for beginners or people with sensitive skin, as it works mainly on the surface without penetrating deeply.

Chemical exfoliation: The most effective and versatile, it uses specific acids to dissolve cellular bonds in a controlled and precise manner.

Chemical acids: your personalized arsenal

Chemical acids are divided into three main subcategories:

AHA (Alpha Hydroxy Acids): Water-soluble and work on the surface. Include mandelic acid (the gentlest), lactic acid (excellent for luminosity) and glycolic acid (the most potent). Glycolic acid is particularly effective because it's the smallest molecule, penetrates deeper and stimulates collagen production.

BHA (Beta Hydroxy Acids): Represented mainly by salicylic acid, it's oil-soluble and can penetrate pores. It's ideal for oily and acne-prone skin, as it helps unclog pores and reduce inflammation.

PHA (Poly Hydroxy Acids): The gentle cousins of AHAs, with larger molecules that work on the surface. They have additional antioxidant properties and are perfect for very sensitive skin or delicate areas like the eye contour.

How to choose according to your skin type

For oily and acne-prone skin: Opt for 2% salicylic acid. You can use it in toner form if your skin tolerates it well, or in cleanser if you're sensitive. Salicylic pads offer application control and allow you to avoid sensitive areas.

For dry skin: Glycolic acid is your best ally. In addition to exfoliating, it acts as a moisturizer, helping to retain water in the skin. A mask with 15% glycolic can transform your skin's texture.

For sensitive skin: Start with mandelic acid or gluconolactone (a PHA). These larger, gentler acids will allow you to get benefits without irritation.

For combination skin: Identify your main concern. If you have spots and seek luminosity, lean towards glycolic and lactic. If your problem is clogged pores, salicylic will be more effective.

Correct application routine

Exfoliation should be done at night, on clean, dry skin. Start with one or two times per week and gradually increase to a maximum of four times per week. In winter you can exfoliate more frequently, while in summer it's better to reduce frequency.

Masks offer unique advantages: they allow localized application, time control and create a natural barrier against overuse. A slight initial tingling is normal and should disappear in 1-2 minutes.

Common mistakes to avoid

Never exfoliate if you have active rosacea, compromised skin barrier or irritated skin. Avoid the area around the nostrils where products can accumulate and cause perioral dermatitis. Always use sunscreen the next day, as exfoliation increases sun sensitivity.

The key is to listen to your skin and adjust the routine according to its weekly needs, not daily. With patience and consistency, exfoliation can completely transform the texture, luminosity and overall health of your skin.