Hey there! I was on 115 mg of minocycline a few years ago. Most antibiotics take about 6-12 weeks to show any improvement of your skin, so don't stress too much. Although if in a few more weeks (I'd say give it 2 more) you really think your skin has taken a turn for the worst then please talk to your derm. Mine took a few weeks to show any results, but when it did they were great! The only problem is that after a whole year on mino I developed intercranial hypertension and had to be taken off. I'm not trying to scare you, I'm just telling you to be wary. Antibiotics are a tricky solution to acne. I'm on one right now because my skin has gotten really bad and they usually heal better than topicals (for me at least), but I plan to stop as soon as I can.

Minocycline made my acne a little worse for a few weeks but by the end of month one, I was clear and stayed that way until three months after I stopped mino. I did this twice! I agree though, if it's not better by the end of one month, you might want to make another appointment.