Retinol
Retinol is a vitamin A derivative that speeds up skin cell turnover, which is why it helps with acne, texture, and pigmentation all at once — and why it needs the slowest, most careful introduction of anything in this list. Most of the bad experiences people have with retinol come from starting too strong, too often, too soon.
How to introduce it
2x
Starting / week
7x
Target / week
6w
Ramp period
12w
Fair to judge by
Possible purging window: weeks 2–6 — temporary increased breakouts as turnover speeds up. Don't stop or judge the ingredient during this window.
Rules that don't bend
- Patch test on the inner forearm 48 hours before first facial use.
- PM only — never apply under sunscreen or in daylight.
- Sunscreen is mandatory every morning after any retinoid night, no exceptions.
- Never combine with AHA, BHA, or benzoyl peroxide in the same session.
- Do not apply to broken, sunburned, or actively irritated skin.
- Buffer with moisturizer underneath if stinging occurs — do not stop the ramp on the first uncomfortable night.
Stop and back off if
- — Stinging or redness lasting more than 60 seconds after 3+ uses.
- — Visible peeling beyond light, dry flaking.
Don't combine with
Same-night use can irritate skin or cancel out the active — alternate nights instead of layering them together.