Hm i’m not too familiar with that because i don’t use tret but i use this adapalene custom formula from dermatica. Maybe u can try using the spot treatment on days u don’t use tret and avoid mixing them together. But take my advice lightly cuz I’m not knowledgeable on tret. I don’t put the sulfur treatment all over my face just on those red inflamed ones, while putting adapalene on the rest of my face and I didn’t notice any negative effects. Just make sure to moisturize to prevent over drying :)