When Do You Need Backup Birth Control on the Pill?

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Backup birth control usually means condoms or avoiding sex for a short period while your birth control pill becomes reliable again. It is one of the most confusing parts of taking the pill because the answer changes depending on the situation.

Sometimes you do not need backup at all. Sometimes you need it for 48 hours. Sometimes you need it for 7 days. Sometimes emergency contraception may also be worth considering. This guide gives you a clear US-focused overview of the most common times backup birth control may be needed.

First: Backup for What?

The birth control pill helps prevent pregnancy. It does not protect against sexually transmitted infections. Condoms can help reduce STI risk, whether or not you need them for pregnancy backup. In this article, "backup" means using condoms or avoiding vaginal sex because pregnancy protection from the pill may be reduced.

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Starting the Pill for the First Time

If you start combined birth control pills within the first 5 days of your period starting, CDC guidance says no additional contraceptive protection is needed.

If you start more than 5 days after your period started, CDC guidance says to use condoms or avoid sex for the next 7 days.

For progestin-only pills, timing rules vary by pill type. Traditional norethindrone or norgestrel mini pills and newer pills like Slynd have different instructions, so check your package insert or ask a pharmacist.

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Starting a New Pack Late

If you start a new active pill pack late after placebo pills or a hormone-free break, you may need backup. The risk is higher when the hormone-free break is extended.

For combined pills, if active pills are missed for 48 hours or more, CDC guidance recommends using condoms or avoiding sex until active pills have been taken for 7 consecutive days. This is especially important at the beginning of a new pack because that is when a late start can extend the hormone-free interval.

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Missing One Combined Active Pill

If one combined active pill is late or missed, you may not need backup if you catch up correctly. CDC guidance says to take the late or missed pill as soon as possible and continue the remaining pills at the usual time. That may mean taking two pills in one day.

However, if you are not sure how many pills you missed, treat the situation more cautiously and use condoms until you confirm.

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Missing Two or More Combined Active Pills

If you missed pills for 48 hours or more, backup is recommended. CDC guidance says to take the most recent missed pill as soon as possible, discard other missed pills, keep taking the pack, and use condoms or avoid sex until active pills have been taken for 7 consecutive days.

If this happened during the last week of active pills, you may need to skip the placebo week and start the next pack immediately. If this happened during the first week and you had sex without a condom in the previous 5 days, emergency contraception may be considered.

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Missing a Progestin-Only Pill

Traditional progestin-only pills are less forgiving than combined pills. The CDC considers norethindrone or norgestrel progestin-only pills missed if they are more than 3 hours late.

If you take Camila or another traditional mini pill, check the exact backup rule for your pill. Many instructions recommend backup for 48 hours after a missed traditional mini pill. Slynd has different missed-pill instructions, so do not apply Camila rules to Slynd or vice versa.

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Vomiting or Diarrhea

Vomiting and severe diarrhea can complicate pill protection. For combined pills, CDC guidance says that if vomiting or diarrhea occurs within 24 hours after taking a hormonal pill, or continues for 24 to less than 48 hours, taking another pill is unnecessary, and no additional contraceptive protection is needed.

If vomiting or diarrhea continues for 48 hours or more, CDC guidance recommends continuing pills if possible and using condoms or avoiding sex until active pills have been taken for 7 consecutive days after symptoms have resolved. Emergency contraception may be considered if this happened during the first week of a new pack and sex without a condom occurred in the previous 5 days.

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After Plan B

After taking Plan B or another levonorgestrel emergency contraception pill, CDC guidance says regular contraception can be started or resumed immediately. But you should use condoms or avoid sex for 7 days.

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After Ella

Ella is different. It contains ulipristal acetate. CDC guidance recommends waiting at least 5 days before starting or resuming hormonal contraception after ella. After restarting, use condoms or avoid sex for 7 days.

This distinction is important enough to repeat: Plan B and ella do not have the same restart rules. See ella and birth control pills: when to restart the pill for the full details.

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Medicine Interactions

Some medicines can reduce the effectiveness of birth control pills. These include certain seizure medicines, some tuberculosis medicines such as rifampin, and some other medications or supplements. Most common antibiotics do not reduce pill effectiveness, but there are exceptions.

If you are prescribed a new medication, ask the pharmacist: "Does this interact with my birth control pill, and do I need backup?"

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