I have a personal experience PhD on the subject. I had acne from about 15 to 20 years of age. My mother took me to various dermatologists and I was put through the ringer, basically they all used me as a Guinea Pig. They had me on anti-biotics for 4 years Tetracycline and later E-Mycin. They used radiation treatments on me to reduce the oil glands, it was supposed to be 14 treatments over a period of time, but I only did two and stopped it. Crazy doctors! They used some kind of a Freon like spray to freeze the pimples, it worked but burned my face.  My face looked like I had Tiger stripes. I only did it once. I told you the doctors were just winging it, they were charging their patients to experiment on them. All of this still goes on, if people just blindly listen to what they say. There's worse stuff today, though the radiation was pretty insane. 

Now, all of the time I was going to all of these quacks, my Aunt kept telling me to just go to the dermatologists to have them clean my face with surgical instruments (pins and knives)? I never paid her any attention, till finally when I was 18 years old I went to her dermatologists. He had a certified nurse that did the surgical cleanings ( I say surgical to distinguish it from facials done by beauticians. They are not licensed to cut you, and just squeeze the pimples, which is not good.). When the nurse cuts and pricks the pimples with the surgical instruments, it is a clean cut which heals with no scarring, as opposed to squeezing and popping a pimple, which leaves a star burst scar. When I would come out of the nurses office, I would be red and swollen, but the next morning when I woke up, I was clean as a whistle. I wish I had done that since I was 14, I would not have a scar on my face. By the time I was 20, I was past it all. Being a man, shaving every day over time clears the scars away. 

My advise, go get your face cleaned at a dermatologist, and forget all the drugs. All the good diet suggestions posted here are also crucial.