Is the pill still effective if you miss one? A Guide

With typical use, the birth control pill is about 93% effective, meaning about 7 out of 100 users get pregnant each year. A common concern is: Is the pill still effective if you miss one? The answer depends on the pill type and how many you've missed.

Quick Summary

Missing a birth control pill can increase pregnancy risk. Your next steps depend on your pill type (combination or progestin-only), how many doses were missed, and when in the pack it happened. Using backup contraception may be necessary.

Key Points

• One Missed Combo Pill: If you miss one combination pill, take it as soon as you remember. You are likely still protected and don't need emergency contraception.

• Two or More Missed Combo Pills: If you miss two or more combination pills, use a backup method like condoms for the next 7 days and consider emergency contraception if you had unprotected sex.

• Minipill Timing is Critical: For traditional progestin-only pills (minipills), being more than 3 hours late is considered a missed pill and requires backup contraception for 2 days.

• Inactive Pills: Missing an inactive (placebo) pill at the end of a combination pack does not increase your risk of pregnancy.

• Sickness Matters: Vomiting or severe diarrhea shortly after taking a pill can reduce its effectiveness; treat it as a missed pill.

• Medication Interactions: Certain medications, such as some antibiotics, anti-seizure drugs, and St. John's Wort, can make birth control less effective.

• When in Doubt, Use Backup: If you are unsure whether your contraceptive protection has lapsed, use a backup method like condoms until you can clarify with a healthcare provider.

How Birth Control Pills Prevent Pregnancy

Oral contraceptives use hormones to prevent pregnancy. There are two main types: the combination pill and the progestin-only pill (or "minipill").

• Combination Pills: These contain both estrogen and progestin. They primarily work by suppressing ovulation and also thicken cervical mucus and thin the uterine lining. Most 28-day packs include 21-24 active hormone pills and a week of inactive (placebo) pills.
• Progestin-Only Pills (Minipills): These contain only progestin. They mainly thicken cervical mucus and can sometimes suppress ovulation. Timing is critical with minipills.

What to Do If You Miss a Combination Pill

If you miss a combination pill, the steps to take depend on the number of pills missed and the time elapsed.

If You Missed ONE Pill (<48 hours since last dose)

Missing one combination pill or taking it less than 48 hours late typically does not significantly reduce pregnancy protection.

• Action: Take the missed pill as soon as remembered and continue the pack at the usual time, even if it means taking two pills in one day.
• Backup Contraception: Generally not needed.
• Emergency Contraception (EC): Not usually necessary.

If You Missed TWO or More Pills (≥48 hours since last dose)

Missing two or more consecutive combination pills compromises pregnancy protection.

• Action: Take the most recently missed pill immediately and discard others. Continue the pack daily.
• Backup Contraception: Use a backup method or avoid sex for seven consecutive days of taking hormonal pills.
• Emergency Contraception (EC): Consider EC if unprotected sex occurred in the past five days, especially if pills were missed in the first week.

If pills are missed in the last week of active pills (days 15-21), skip the placebo pills after finishing the active ones and start a new pack immediately.

What to Do If You Miss a Progestin-Only Pill (Minipill)

The window for taking minipills is smaller. The actions required depend on the specific minipill type.

• Traditional Minipills: If more than 3 hours late, it's a missed pill.
  • Action: Take the missed pill ASAP and continue as scheduled. You might take two in one day.
  • Backup Contraception: Use a backup method for the next 48 hours after resuming pills correctly.
  • Emergency Contraception (EC): Consider EC if unprotected sex occurred since the missed pill.
• Drospirenone Minipills:
  • If you miss one pill (<48 hours since last dose): Take ASAP and continue as normal. No backup needed.
  • If you miss two or more pills (≥48 hours since last dose): Take the most recent missed pill, discard others, and continue the pack. Use backup for 7 days.

Missed Pill Quick Guide

Pill Type	How Many Missed	Action	Backup Needed?	EC Needed?
Combination	1 pill (<48 hrs)	Take missed pill ASAP. Continue pack as normal.	No	Generally no
Combination	2+ pills (≥48 hrs)	Take most recent missed pill ASAP. Discard others. Continue pack.	Yes, for 7 days	Yes, if unprotected sex occurred
Minipill (Traditional)	1 pill (>3 hrs late)	Take missed pill ASAP. Continue pack as normal.	Yes, for 2 days	Yes, if unprotected sex occurred
Minipill (Drospirenone)	1 pill (<48 hrs)	Take missed pill ASAP. Continue pack as normal.	No	No
Minipill (Drospirenone)	2+ pills (≥48 hrs)	Take most recent missed pill ASAP. Discard others. Continue pack.	Yes, for 7 days	Yes, if unprotected sex occurred in the first week

Other Factors Affecting Pill Effectiveness

Vomiting or severe diarrhea within a few hours of taking a pill can reduce absorption; treat this as a missed pill and use backup until the illness resolves for at least two days. Certain medications like Rifampin, some anti-seizure drugs (e.g., topiramate), certain HIV drugs, and St. John's Wort can interfere with effectiveness. Always inform your healthcare provider about all medications and supplements.

Conclusion

Missing one combination pill typically does not compromise protection. However, missing two or more combination pills, or taking a traditional minipill more than three hours late, requires prompt action and backup contraception. Knowing the guidelines for your specific pill type is essential. If unsure, use a backup method and consult a healthcare provider or pharmacist.

For more detailed guidance, please refer to the CDC's Recommendations for Contraceptive Use.

Frequently Asked Questions

What should I do if I miss one combination birth control pill?

Take the missed pill as soon as you remember, even if it means taking two pills in one day. Then, continue taking the rest of your pack as usual. You do not need a backup method of birth control.

What if I miss a progestin-only pill (minipill)?

If you are more than 3 hours late taking a traditional minipill, take it as soon as you remember and use a backup method of contraception (like condoms) for the next 48 hours.

Do I need emergency contraception if I miss one pill?

If you miss only one combination pill, you generally do not need emergency contraception. However, if you miss a traditional minipill by more than 3 hours or miss multiple combination pills and have had unprotected sex, you should consider it.

What happens if I miss an inactive (placebo) pill?

Nothing. Placebo pills contain no hormones and are there to help you stay in the habit of taking a pill every day. Missing one does not affect your pregnancy protection. Just make sure to start your next pack on time.

I missed two combination pills in a row. What should I do?

Take the most recent pill you missed as soon as possible and throw away the other missed pills. Continue your pack as normal, but use a backup method like condoms for the next seven days. Consider emergency contraception if you had unprotected sex in the last 5 days.

Can vomiting or diarrhea make my birth control pill less effective?

Yes. If you vomit within a couple of hours of taking your pill or have severe diarrhea, your body may not have absorbed the hormones. You should treat it as a missed pill and use a backup method.

Which medications can interfere with birth control pills?

Certain medications can reduce the effectiveness of birth control pills, including the antibiotic rifampin, some anti-seizure drugs (like carbamazepine and topiramate), some HIV medications, and the herbal supplement St. John's Wort.