What Exactly Is Exfoliation?

"Exfoliation" is a common step in skincare, and many people believe that regular exfoliation can make the skin smoother and more radiant. However, what exactly does exfoliation remove? Is it really beneficial for the skin? Today we'll delve into this topic.

1. What Is the Stratum Corneum?

The stratum corneum is the outermost layer of the skin, composed of dead corneocytes stacked like fallen leaves. Its main functions include:

🛡️ Protective Function

Preventing harmful substances such as bacteria and chemicals from invading the skin.

💧 Moisture Retention

The lipids between corneocytes help lock in moisture and maintain skin hydration.

🌡️ Resistance to External Stimuli

Such as UV rays, temperature changes, and wind.

The stratum corneum acts like the skin's "armor," and its thickness varies from person to person. People with oily skin typically have a thicker stratum corneum, while those with dry skin or sensitive skin have a thinner one.

2. What Is the Essence of Exfoliation?

Exfoliation, as the name suggests, accelerates the shedding of corneocytes. Its effect can be understood as "polishing" the skin surface to remove dead skin cells more quickly. Common methods include:

Physical Exfoliation

Such as scrubs, cleansing brushes, and facial cleansing devices, which remove dead skin through friction.

Chemical Exfoliation

Such as AHAs and salicylic acid, which soften the connections between corneocytes to promote their shedding.

While the skin may appear smoother and brighter shortly after exfoliation, frequent exfoliation over the long term can lead to a series of problems.

3. Common Misconceptions About Exfoliation

❌ Misconception 1: Do "Dead Skin Cells" Need Manual Removal?

Many people believe that the "dead skin" on the skin surface needs to be removed through exfoliation products, otherwise it would affect skin metabolism. In fact, the skin has the ability to renew itself, and dead skin cells naturally shed without additional intervention.

Under normal circumstances, cells deep in the epidermis continuously divide and grow, gradually pushing outward to eventually form the stratum corneum and naturally shed. This is a spontaneous process that we usually don't notice.

❌ Misconception 2: Can Exfoliation Improve Closed Comedones and Acne?

Some people exfoliate to improve closed comedones, blackheads, or acne. However, the causes of acne are very complex, including:

• Hormonal fluctuations (such as during menstruation)
• Excessive stress
• Genetically oily skin
• Improper skincare or dietary habits

Exfoliation may help some people, such as those with excessively thick stratum corneum causing clogged pores. However, for most people, exfoliation cannot fundamentally solve acne problems and may even worsen inflammation due to over-stimulation.

❌ Misconception 3: Does Keratosis Pilaris Require Exfoliation?

Keratosis pilaris is a common skin condition characterized by small bumps on the skin surface. Many people try to improve it through exfoliation, but this method is not recommended.

The accumulation of stratum corneum in keratosis pilaris is localized, while exfoliation products often cannot precisely target the raised areas, instead wearing down normal skin, thinning the stratum corneum, and causing sensitivity, redness, and other issues.

4. Dangers of Over-Exfoliation

Frequent exfoliation can damage the skin's barrier function, leading to the following problems:

🔻 Thinning Skin

Over-removal of the stratum corneum reduces the skin's defense against external stimuli, making it prone to sensitivity.

💧 Dry Skin

After stratum corneum damage, the water-locking ability weakens, making the skin prone to dryness and peeling.

🦠 Microbiome Imbalance

Disruption of the skin surface flora can lead to dermatitis, eczema, and other issues.

⚠️ Sensitivity and Inflammation

After skin barrier damage, the skin becomes more sensitive to external stimuli (such as skincare ingredients, environmental changes), easily causing redness, itching, stinging, and other symptoms.

5. Who Should Exfoliate? Who Should Avoid It?

✅ People Suitable for Exfoliation

Oily Skin: Thicker stratum corneum and prone to clogged pores can appropriately exfoliate, but frequency should be controlled.

Thick Stratum Corneum: Those with rough skin and hard texture can occasionally exfoliate.

❌ People Who Should Avoid Exfoliation

Dry Skin: Thin stratum corneum, exfoliation will worsen dryness and sensitivity.

Sensitive Skin: The skin barrier is already damaged, exfoliation will exacerbate the problem.

Acne-Prone Skin: Especially inflammatory acne, exfoliation may irritate the skin and cause worsening.

6. How to Exfoliate Scientifically?

If you really need to exfoliate, please follow these principles:

📅 Control Frequency

Oily skin 1-2 times per month is sufficient, dry and sensitive skin should avoid it as much as possible.

🌸 Choose Gentle Methods

Prioritize low-concentration chemical exfoliation products (such as gentle AHAs) and avoid using coarse-grained scrubs.

🚫 Avoid Stacking Stimuli

Do not use multiple exfoliation products simultaneously, and avoid exfoliating when the skin condition is unstable (such as after allergies or sunburn).

🧴 Follow-up Repair

After exfoliation, promptly use moisturizing and repair products to help the skin restore its barrier function.

7. Summary

Exfoliation is not a necessary step in skincare. The skin has the ability to renew itself, and in most cases, no additional intervention is needed. Frequent exfoliation can actually damage the skin barrier, leading to sensitivity, dryness, and other issues.

If your skin condition is good, simply focus on gentle cleansing, moisturizing, and sun protection. For those with thick stratum corneum or oily skin, exfoliation can be done appropriately, but frequency must be controlled to avoid overdoing it.

Remember, the core of skincare is "protection," not "harassment." Scientific skincare is what makes the skin healthy and beautiful!