Physical exfoliation — granules, scrubbing pads, brushes — sells the sensation of deep cleansing. It's a sensation, not a result. The micro-cuts created by irregular granules are invisible to the naked eye but measurable by skin microscopy. Accumulated over months of daily use, they contribute to barrier degradation, subclinical inflammation and paradoxically worse cell turnover. Chemical exfoliation works differently — and better.

How Chemical Exfoliation Works

AHAs (alpha-hydroxy acids — lactic, glycolic, malic, mandelic) and BHAs (salicylic acid) dissolve the bonds between corneocytes (dead surface cells) uniformly, without mechanical trauma. Lactic acid is the gentlest: larger molecule than glycolic, penetrates more slowly, less irritating, suitable for sensitive and mature skin.

AHA vs. BHA: When to Use Each

• AHA (lactic, glycolic) — skin surface, excellent for dark spots, uneven tone, fine lines, dull skin. Water-soluble.
• BHA (salicylic acid) — lipid-soluble, penetrates the pore, ideal for acne, comedones, enlarged pores. The only AHA/BHA that acts inside the follicle.

Correct Frequency by Skin Type

• Oily/combination: AHA 2–3x/week + BHA 1–2x/week on alternating days
• Normal: AHA 2x/week
• Dry/mature: lactic acid 1–2x/week
• Sensitive/reactive: mandelic acid 1x/week or complete pause

Rules Never Broken With AHAs

1. SPF mandatory in the morning after an AHA night — increases photosensitivity by 50%
2. Don't combine with retinol/bakuchiol in the same application
3. Don't use in the first 2 weeks of a new routine