"i am 31 years old male and currently taking 100mg once a day. i have taken doxy 3 years ago for 4 months and it definitely worked like a miracle back then. i am glad my skin stayed fine for 3 years!! sad part is..its back again! i never had any side effects especially if you are having plenty of fluids and not mixing with other supplements such as iron and multivits tablets. in the beginning i felt as if my skin was more responsive to hot and cold temperatures but it&#039;s gone now. i would highly recommend doxy to all suffering from mild to severe acnes but you have to be patient to see it working!"