Doxycycline × Ethinylestradiol

Doxycycline does not affect hepatic ethinylestradiol metabolism. The historical theory of reduced COC efficacy via suppression of enterohepatic recirculation is rejected by meta-analyses.

The combination usually causes no specific symptoms. Each drug's individual side effects remain.

Additional contraception during short doxycycline courses is not needed. For long-term therapy (e.g. acne, Lyme disease), no adjustment either.