"i am 26 and have adult onset acne. i&#039;ve always had completely clear skin until about 3 years ago. it is moderate in severity, mainly on my cheeks and chin. makeup covers it up ok usually but it&#039;s definitely there underneath. 5 days ago i started on 100mg doxycycline once a day, and putting topical differin gel on at night. in that short time i am amazed that my acne/discoloration has decreased by about 30%. i already see a significant marked change, as no new pimples have formed since starting it, and my existing ones are drying up and shrinking. the darker spots from previous ones healing has lightened. i&#039;m very excited to go back in 6 weeks hopefully with a make-up free face. no side effects from the meds that i&#039;ve noticed whatsoever."