SkinWis
SkinWis Scientific
Optimization Protocol

How to Layer Skincare:
Retinol, Vitamin C & Acids

An effective routine is more than a list of products—it is a strategic sequence designed to maximize absorption while preserving the Acid Mantle.

Skincare layering guide

The Hierarchy of Application

01
Phase: Prep

Cleanse

The foundation. Use a pH-balanced surfactant (5.5) to remove debris without disrupting the lipid barrier. Avoid 'squeaky clean' sensations.

02
Phase: Treat

Active Serums

This is where pH-sensitive molecules (Vitamin C, Retinoids, Acids) live. Apply to clean skin to ensure direct pathway to the epidermis.

03
Phase: Support

Hydration & Repair

Water-based humectants (Hyaluronic Acid, Panthenol) draw moisture in, while peptides support collagen synthesis.

04
Phase: Seal

Seal & Protect

Occlusive moisturizers trap previous layers. In the AM, this must be followed by SPF 30+ to prevent UV degradation of actives.

The 4-Night Clinical Cycle

Strategically preventing over-exfoliation and chronic inflammation.

Night 1

Exfoliate

Chemical acid (AHA/BHA) to prep surface.

Night 2

Retinoid

Tretinoin or Retinol for cell turnover.

Night 3

Recovery

Barrier repair, Ceramides, no actives.

Night 4

Recovery

Deep hydration and lipid replenishment.

AM: Protection

  • Antioxidant Defense: Vitamin C (L-AA) to neutralize free radicals from pollution.

  • SPF Non-Negotiable: Actives like retinoids make skin more photosensitive.

PM: Correction

  • Double Cleanse: Use an oil cleanser first to dissolve stubborn SPF and sebum.

  • Repair Actives: Night is the peak time for DNA repair and cellular mitosis.

Layering Conflicts

Retinoids + Benzoyl Peroxide

BP can oxidize certain retinoids (like Tretinoin), rendering them inactive.

Vitamin C + Copper Peptides

The copper can degrade L-Ascorbic Acid, causing oxidation.

The "Sandwich" Technique

"For sensitive skin starting Retinoids: Apply a thin layer of moisturizer, then your active, then another layer of moisturizer. This slows penetration without blocking efficacy."