I used the serum for two nights now together with my grapeseed oil (for my acne breakout) and tamanu oil as spot treatment. I have active pimples and it did not sting upon application on those parts. I can say that it did brighten my face and it looks like I was wearing foundation? because my pores are not so visible and my skin looks more even. IDK how to explain it. My acne scars faden and others turned from brownish to pinkish brown. I am excited on the effect if I use it on a long term basis. I found the serum expensive but if the good effects gets better and better on long term usage, I wouldn't mind buying this again.