The protocol
Skin cycling is a scheduling pattern popularized for retinoid and exfoliating-acid users who overdid it:
- Night 1 — retinoid (e.g. retinal)
- Night 2 — exfoliating acid (e.g. AHA), never stacked with the retinoid
- Nights 3–4 — recovery: gentle cleanse, hydrators, ceramides, no actives
- Repeat
Why spacing works
Strong actives create micro-stress that the barrier needs time to recover from. Compressing retinoids and acids into consecutive nights accumulates that stress faster than skin can repair — the result is retinization-style dryness, flaking, and sensitivity. Rest nights let the barrier rebuild.
Adjusting the cycle
- Sensitive or dry skin: extend to 1 active + 3 recovery nights
- Tolerant skin: some people drop to 1 recovery night — but never zero
Coyglow note: our routines encode this idea natively — the PM plan alternates active nights with barrier-repair nights instead of stacking.