Yes, they will definitely affect the effectiveness of these pills. Both anavar and these pills are hormones, and they will interact between each other. Therefore, if you are going to use anavar, you will have to find a different birth control method. Also, you can consider using SARMS - they are non-hormonal, so they will no affect your birth control pills, and you will be able to use them simultaneously. Besides, SARMS are very effective, and they have considerably less side effects than steroids, including anavar.