2 doctors weighed in:
Does anyone know if the medication Flagyl has any side effect to make birth control ineffective?
2 doctors weighed in

Dr. Joseph Eastern
Dermatology
1 doctor agrees
In brief: No.
Despite what you may have heard or read on-line, there is no evidence that Flagyl interferes with birth control pills, and there is no such warning in the package insert.
Your prescribing doctor may still tell you to use a back-up form of birth control “just in case”, but there is no evidence that it's necessary. Remember also that no birth control method is 100% effective in preventing pregnancy.

In brief: No.
Despite what you may have heard or read on-line, there is no evidence that Flagyl interferes with birth control pills, and there is no such warning in the package insert.
Your prescribing doctor may still tell you to use a back-up form of birth control “just in case”, but there is no evidence that it's necessary. Remember also that no birth control method is 100% effective in preventing pregnancy.
Dr. Joseph Eastern
Dr. Joseph Eastern
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