Bleeding for two Months on Implanon

Dear Ask The Doctor: I am on Implanon Birth Control and have been bleeding for two months, What could be causing this?

Dear Chelsea: Frequent or unpredictable bleeding is the major side effect of Implanon. Women using Implanon who have higher circulating estradiol levels and ovarian follicle activity may be at greater risk of abnormal patterns of bleeding. Some studies have found that doxycycline, 100 mg twice daily for 5 days significantly reduced prolonged bleeding associated with implanon.