benzoyl peroxide, i use 4% > brevoxyl. also depending on severity u can try from diet(lo gi foods, less stuff in the evening, etc) to even accutane (although ..). along diet there are some benefits of vit A, etc, DIM, and other stuff. the thing indeed they are weak, and an easily available doxy + a topicall antibiotic would erase all acne in a week (like brevoxyl did- but bp stuff u have to take forever), but in an year or so it will come back with vengeance and u lower ur general health.
don't know how a doctor would suggest antibiotics and not give you a prescription, but that's your bussiness.
there are some cathegories of antibiotics.
my derm prescribed me doxycycline internally (1-2moths i think), and zynerit externally 3moths (erhythromycin antibiotic). like i mentioned this works great, it cleared me within 1 week(but i did continued the treatment). my derm almost didn't care how my back acne was before this prescription so it seems it's a usual combo for acne sufferers.
again, after one year and a half, it slowly came back, but this time my immune was so low my nose got stuck all the time, and even one of my ears was so intrenally infected the doctors though it was a wax plug initially. also urinary infections.
anyway that's it.