Does applying a serum over Tretinoin make it less effective?

February 1, 2022
Asked By:Selena8245 in England, United Kingdom

Hi I’m 39I’ve been using Tretinoin,ketrel 0.5for over a year now for pores & wrinkles.My skin is used to it& I use it every night.I don’t have sensitive skin&i don’t get side effects anymore.I apply it at night after cleansing&applying Biologique Recherche P501970-I know it says not to use it with that but the spa said it’s fine& I’ve had no side effects..I want to know after applying the Tretinoin and waiting for it to sink in etc, does applying any serum or cream make tret less effective?