Can doxycycline effect the depo-provera birth control shot?

No: antibiotics are not that supect anymore to decrease thr effectiveness of Depo-Provera or other birthcontrol

Birth control/abx: No. Many meds (espescially antibiotics taken in pill form and several anti-seizure meds) can because when absorbed in the gut they pass through the liver and are metabolized which can affect the effectiveness of birth control pills. Delivered quite a few babies from moms on BCP who conceived after given antibiotics pills for infection. Depo is a shot/ does not pass through the liver.