Skincare Ingredient Conflict Checker
Select the active ingredients in your routine. We'll tell you which ones clash, which are safe together, and how to fix your layering order.
What's in your routine?
Search and add every active ingredient you use.
How ingredient conflicts work
pH Conflicts
Some ingredients need acidic environments (vitamin C at pH 3.5) while others need neutral pH (retinol at pH 5.5-6). Mixing them reduces the effectiveness of both.
Chemical Deactivation
Strong oxidizers like benzoyl peroxide can chemically degrade antioxidants like vitamin C and retinol on contact, rendering them useless.
Over-Stimulation
Layering multiple exfoliants or active ingredients overwhelms the skin barrier, causing redness, peeling, dryness, and increased sensitivity.
Golden rules for layering actives
Vitamin C in the morning, retinol at night
This is the single most impactful split. Vitamin C protects against UV damage during the day; retinol works on cell turnover while you sleep.
Never double up on exfoliants
One chemical exfoliant (AHA or BHA) per routine is enough. Adding scrubs on top is the #1 cause of barrier damage.
Buffer with hydrators
Hyaluronic acid, ceramides, and niacinamide are "peacekeeper" ingredients — they can go between actives to reduce irritation.
When in doubt, alternate nights
If two ingredients conflict, the simplest fix is to use them on different days. Monday/Wednesday/Friday for acids, Tuesday/Thursday/Saturday for retinol.
Want to check products against your allergies too?
AllerNote doesn't just check ingredient conflicts — it checks every product against your personal allergy profile. Add your specific triggers once, and every scan is personalized.