The Bottom Line

Exfoliation removes dead skin cells from the surface, revealing brighter, smoother skin underneath. Chemical exfoliants (AHAs, BHAs, enzymes) are generally preferred by dermatologists because they work more evenly and are less likely to cause micro-tears. Physical exfoliants (scrubs, brushes) can work but require gentle technique. Over-exfoliation is the most common mistake — 2-3 times weekly is sufficient for most people.

Chemical Exfoliation

Chemical exfoliants dissolve the "glue" (desmosomes) between dead skin cells, allowing them to shed naturally. No scrubbing required.

AHAs (alpha-hydroxy acids):

  • Glycolic acid, lactic acid, mandelic acid
  • Water-soluble — work on the skin surface
  • Best for: sun damage, fine lines, dullness, hyperpigmentation, dry/rough texture
  • Increase sun sensitivity — sunscreen is mandatory

BHAs (beta-hydroxy acids):

  • Salicylic acid (primary BHA)
  • Oil-soluble — penetrates INTO pores
  • Best for: acne, blackheads, oily skin, congested pores
  • Anti-inflammatory — gentler than AHAs for inflamed skin

Enzymes:

  • Papain (papaya), bromelain (pineapple)
  • Gentlest chemical exfoliation method
  • Break down keratin protein on the surface
  • Best for: sensitive skin, rosacea-prone skin

PHAs (polyhydroxy acids):

  • Gluconolactone, lactobionic acid
  • Largest molecule size — gentlest AHA-type acid
  • Also function as humectants (attract water)
  • Best for: very sensitive skin, eczema-prone skin

Physical Exfoliation

Physical exfoliants manually remove dead cells through friction:

  • Fine-grain scrubs: Products with small, round particles (jojoba beads, rice bran). Gentler than large, jagged particles.
  • Washcloths and konjac sponges: Provide very mild physical exfoliation during cleansing. Good for beginners.
  • Cleansing brushes (Clarisonic-style): Oscillating brushes that dislodge dead cells. Can be too aggressive for sensitive skin. Company (Clarisonic) went out of business in 2020, partly because chemical exfoliation gained evidence-based preference.

What to AVOID:

  • Scrubs with large, sharp particles (walnut shell, apricot kernel) — create micro-tears in the skin
  • St. Ives Apricot Scrub — the most notorious example of overly aggressive physical exfoliation
  • Harsh loofas or rough washcloths on the face

Chemical vs Physical: Which Is Better?

Dermatologists generally prefer chemical exfoliation because:

  • More even, controlled exfoliation across the skin surface
  • No risk of micro-tears from uneven particles
  • Additional benefits beyond exfoliation (collagen stimulation from AHAs, pore clearing from BHAs)
  • Can be precisely dosed and gradually increased

Physical exfoliation still has a place for: body exfoliation (skin is thicker and less sensitive), pre-shave preparation, and people who prefer the immediate tactile feedback of scrubbing.

How Often to Exfoliate

  • Chemical exfoliants: Start 2x/week, increase to 3-4x as tolerated. Daily use of low-concentration BHA (in a cleanser) is fine for most people.
  • Physical exfoliants: 1-2x/week maximum for the face. More on the body is fine.
  • Signs of over-exfoliation: Redness, stinging, increased sensitivity, excessive dryness, shiny/raw appearance. If these occur, stop all exfoliation for 1-2 weeks and focus on barrier repair (ceramide moisturizer).

Frequently Asked Questions

Can I use both chemical and physical exfoliation?

Yes, but not at the same time. Example: chemical exfoliant 2-3 nights per week, gentle physical exfoliation once on a non-acid day. Total exfoliation should not exceed 3-4 times weekly for most people.

Should I exfoliate before or after my other products?

Chemical exfoliants work best on clean, bare skin — apply after cleansing, before serums and moisturizer. Physical exfoliation can be done during the cleansing step (scrub-type cleansers) or as a separate step before other products.

I have acne — should I exfoliate more?

Not necessarily. Over-exfoliation damages the barrier and can worsen acne. A BHA (salicylic acid 2%) used consistently 3-4 times weekly is more effective than aggressive daily scrubbing. Let the acid do the work — don't supplement with physical scrubs on acne-prone areas.

  1. Tang SC, Yang JH. "Dual effects of alpha-hydroxy acids on the skin." Molecules. 2018;23(4):863.
  2. Kornhauser A, et al. "Applications of hydroxy acids." Clinical, Cosmetic and Investigational Dermatology. 2010;3:135-142.
  3. Arif T. "Salicylic acid as a peeling agent." Clinical, Cosmetic and Investigational Dermatology. 2015;8:455-461.