How much will amoxicillin effect my birth control

Use condoms while taking amox.

It lessens the effectiveness. Not sure by how much, but why risk it?

My nephew is the result of failed birth control due to antibiotics. By all means, use an alternative. You might try spermicidal foam instead--it is over the counter, can be inserted a few minutes before sex, and is pretty effective.

This is a funny story! (to me anyway) My daughter, had 2 teenage sons & was living with her second fella for about 6 years
always took the pill--swore by it , said it always worked great! Then one Friday she got sick & went to the emergency room, they said she had pnemonia?(spelling) any way they filled her up with antibiotics & by monday she was way better, she went home & fella took such good care of her! few days later went back to work, feeling tired but better..then 2 months later she went back to the doctor & told him she could not get over being tired & thought maybe she still had a little of that bug left inside her.he said No can not be that,,,so after an exam & some tests he came back & told her she was pregnant! & she was PG with TWINS**** she said it can not be..

she had not missed any pills..he laughed & said did not we tell u that antibotics nulify the pill like u have never taken it!!! she informed him NO, no one had ever told her that before..well I have twin granddaughters that r not alike at all, one is blond & small & one has dark hair & eyes & tall & they r 19 years old this year...

By all means use a back up form of birth control, it is not the end of the world to have to use condoms. :) It DOES decrease the effectiveness, though I do not know the percentage.