The Pairing Cheat Sheet

by Natalie · The City Chic Edit

Worth splitting up

Retinol or retinal + glycolic, lactic or salicylic acid: alternate evenings — e.g. acid twice a week, retinoid on other nights.
Retinol or retinal + vitamin C: vitamin C in the morning, retinoid at night.
Retinol + retinal: pick one retinoid — switch, don't stack.
Glycolic + lactic acid: pick one AHA per routine; lactic is the gentler start.
Copper peptides + vitamin C or exfoliating acids: use them at different times of day.
Two strong actives that both tingle (azelaic, kojic, AHAs, BHA, pure vitamin C): introduce one at a time; split morning and evening if skin complains.

Four habits that keep it simple

One new active at a time. Give it 2–4 weeks before adding the next.
Retinoids and acids: start slow. 2–3 evenings a week, then build up.
SPF 30+ every morning — especially with retinoids, AHAs, vitamin C or spot-fading ingredients.
One formula ≠ two products. If both ingredients are in one product, follow its instructions.

General guidance only, not medical advice. Compatibility depends on the formula and your skin. Follow product instructions and consult your dermatologist when needed.