Skin Cycling

Night 1: chemical exfoliant (AHA or BHA at moderate strength). Night 2: retinoid (retinol, retinaldehyde, or adapalene). Nights 3 and 4: recovery — cleanser, hydrating layers, occlusive moisturiser, nothing active. Night 5: restart at exfoliant night.

Week 1-2 may still show retinoid purge if you're new to vitamin A. Week 4 onwards, barrier should stabilise and flaking drop dramatically. Full collagen and texture results track to 12-16 weeks, same as any retinoid routine — you're trading speed for tolerability, not outcomes.

Skin cycling is a structured routine method popularised in 2022 by Dr. Whitney Bowe, a Mount Sinai dermatologist. The thesis: instead of running exfoliants and retinoids every night, you rotate through a four-night cycle — exfoliation night, retinoid night, two recovery nights — to give the barrier time to reset between actives. The evidence base isn't trial data; it's applied logic built on decades of dermatology practice showing that active tolerance tracks to frequency more than strength. For retinoid beginners and combination/normal skin types, skin cycling reduces purge, flaking, and over-exfoliation complaints that drove people off actives entirely. Not a shortcut: slower routines produce similar gains to daily routines over 12 weeks with dramatically fewer irritation dropouts.