It is suggested that topical medications go on first, and then sunscreen. If sunscreen is applied first, it might interfere with the medication’s penetration and might inactivate the active ingredient. For that reason, medication should always be the first product applied to a clean, washed face.
If you’re also using a moisturizer, it should go after the medication and before the sunscreen. Applying a moisturizer after the medication could actually enhance penetration of the medication. If the moisturizer does not contain an SPF, apply a sunscreen with a SPF of 15 or higher next. Finally, you can apply foundation, powder, blush and any other colored cosmetics.
To recap, the layering process goes as follows: medication, moisturizer, sunscreen, foundation, powder and blush.
