"coming up on 2 months on this 100 mg twice a day. take on a full stomach. it makes me throw up if i haven&#039;t eaten food with it. my skin has progressively gotten worse. i don&#039;t think it is because of the doxycycline, i think my body just wants to continue down the path of giving me acne. i am on it for moderate cystic acne and i am still getting cysts regularly and am now breaking out on my forehead where as before it was just on the jawline. not sure when this is suppose to work but i look pretty darn bad. will finish the treatment and hope for the best :("