"i have had cystic acne since i was 18. it became horrible when i turned 22. i started taking doxcy last may after my acne kept coming back worse than before. i was on tetracycline when i was 18 &amp; it went away. but this time around the acne is on a vengence horribly scarring me. if i miss one dose of this medicine i will get a pimple. i am resistant to basically everything under this doxy. i am on 500mg twice a day. it works in due time but recently i will get sick from taking it and vomit. it doesnt matter at the moment if i eat or not it with it. its sporadic. its a love hate with this medicine. but if you want clear skin its worth it!"