(14, girl) I've been using Cosrx blackhead power liquid for a little over 3 weeks now. 2-3 times a week. I've been using it on my forehead because I have many small bumps on my forehead (chatgpt said they were closed comedones, not sure😅) I feel like it hasn't made any difference.. or that it first gets better then worse (like a loop) after I apply a thin layer of blackhead power liquid, I wait 15 minutes before applying a moisturizer (either Avené tolerance control, or OIL FREE ultra moisturising lotion from cosrx) I also have a bit oily skin but yepsipepsi, feel free to give some tips if you have any! :)