"i just finished 1 week of the doxy therapy. my derm prescribed it for 3 months. i don&#039;t see a major difference but i&#039;m hopeful. it&#039;s only been a week and my derm said it would take about 2-3 months to see improvement. it cleared up the cystic acne on my cheeks and chin but i&#039;ve gotten huge breakouts on my forehead and chest. it upsets my stomach a little but i have tried to avoid dairy immediately before taking doxy."