If minocycline is so effective against chlamydia, how come it is never prescribed by doctors for that? i have only seen it really get prescribed for acne and doxycycline is for chlamydia?

Fewer side effects: Minocycline and doxycycline are equally effective against chlamydia, and taken in the same dose and duration (100 mg twice daily for 7 days). However, doxy is less likely to cause side effects in the recommended doses and therefore is the primary recommendation by almost all public heauth authorites and other STI experts. But mino is fine for someone who tolerates it better or prefers it.

Minocycline had been prescribed for a treatment of Chlamydia infection, however, it's been replaced by current treatment regimen: azithromycin one dose or doxycycline for 1 week. Alternatives are erythromycin or O- and Levofloxacin.