Acne medicine works by taking everything under the skin that will soon be acne and pushing it out. Popular treatments like ClearPores unplug your pores and help to get the bacteria out of your body. Due to that your skin might look worse at the beginning, but you should see it as a part of the healing process. As quickly as skin gets rid of the bacteria, it will recover without any more breakouts. It is a frustrating process, and can take some time, but you will rip the rewards soon, just be patient.
However, you have to see what kind of pimples you have, and then chose an appropriated acne cream for that type of acne. Generally using the wrong type of cream can worsen the problem. It is true that too many chemicals and treatments will dry out your skin, which will only irritate acne further. But, sometimes if your skin just gets too dry it will compensate by producing more oil, then you get more pimples. Some of those popular acne treatments do that to some people. It can happen with most medicines in the beginning but it will all go away soon.
If you have severe acne, just make sure you have a good dermatologist and he/she is on track. You should do fine. If the treatment causes any problems, let your doctor know. If you experience for example, diarrhea, let him know. Otherwise, stick to your acne treatment; give it 7 or 8 weeks to see results. Remember that your doctor is not to deceive you with a quick solution with treatments that never work.