Use this free ingredient clash checker to see whether two skincare actives can go in the same routine, and if not, how to split them between morning and night.
How to use the ingredient clash checker
- Pick the two actives you want to combine.
- Read the result: OK together, use at different times or avoid layering.
- Follow the “how to use both” line to build your routine.
Frequently asked questions
Can I use niacinamide and vitamin C together?
Yes, for most people. The old warning came from lab tests with pure ingredients at high heat. Apply vitamin C first, then niacinamide, or use one in the morning and one at night.
Can I use retinol and niacinamide together?
Yes. Niacinamide supports the skin barrier and can make retinol easier to tolerate. Apply retinol at night, then a niacinamide serum or moisturiser.
Can I use retinol with AHA or BHA?
Not on the same night for most people. Alternate nights and keep at least one rest night a week.
Does this replace a dermatologist?
No. It is general guidance. If you use prescription products such as tretinoin or adapalene, follow your doctor.