& go to a dermatologist for it - IME differin (otc) did not work much but i know for some it does. i use a prescription retinol which has worked super well. also when you start you must commit to SPF daily, keeping skin extra moisturized, and be mindful of what you can’t use much of anymore (like salicylic acid, toners, etc)
caveat - if you have severe, deep scarring (like from cystic acne) it will not do much, ask your dermatologist for alternatives