I have been using this product for a month now. I have sensitive and acne prone skin. I haven't noticed my blackheads to disappear, especially those on my nose. I think that it helps to some extension but not fully. It doesn't dry the skin which is great! It takes time to absorb, though, or at least on my skin.

 I am going to use the bottle that I have, but I am not sure if I'm going to repurchase it. I think I will try with some other serums/essences.

I will just add that the routine that works best for me right now is 1. Clean it Zero (only if I have makeup) 2. Beauty Water 3. COSRX BHA 4. If I have any pimples I use their  patches which are MIRACLE!!! I don't use moisturizer because my skin doesn't need it at the moment, it feels too much if I put whatever moisturizer I have(and so far I have only light formula ones bc it's still summer).

Hope I helped :)