Doxycycline
"It has helped clear up my acne, but it also has given me annoying side effects.  Whenever I take it it always makes my stomach make really loud and embarrassing sounds.  It also gives me indigestion and nausea even if I take it with food.  Yet another side effect is that it makes me dizzy and lightheaded.  I've also noticed that my skin is becoming really itchy and even more sensitive than it normally is.  I've been on it for less than a week and it's great that my skin looks kind of decent again, but I don't think I can put up with the side effects anymore, especially the itching, dizziness, and indigestion.  Looks like I'll have to find something else to help with my moderate acne."