When do you need to take an additional dose of birth control (hormonal contraception) if you vomit after taking it?

When to Take Another Birth Control Pill After Vomiting

If you vomit within 2-3 hours after taking your birth control pill, you need to take another pill as soon as possible. 1

For Regular Combined Oral Contraceptives (COCs)

Vomiting Within 24 Hours of Taking the Pill

• No need to take another pill (redose) 2
• Continue taking your pills daily at the usual time, even if you feel uncomfortable 2
• No backup contraception is needed 2
• Emergency contraception is not usually needed but can be considered if appropriate 2

Vomiting Continuing for 24 to Less Than 48 Hours

• Continue taking pills daily at the usual time 2
• Use backup contraception (like condoms) or avoid sex until you've taken hormonal pills correctly for 7 consecutive days after vomiting stops 2
• If vomiting occurred during the last week of hormonal pills (days 15-21 for 28-day packs), skip the hormone-free interval by finishing the current pack and starting a new pack the next day 2
• Consider emergency contraception if vomiting occurred during the first week of a new pill pack AND you had unprotected sex in the previous 5 days 2

Vomiting Continuing for 48 Hours or Longer

• Follow the same recommendations as for 24-48 hours of vomiting 2
• Use backup contraception or abstain until 7 consecutive days of correct pill-taking after symptoms resolve 2

For Progestin-Only Pills (POPs)

If Vomiting Occurs Within 3 Hours of Taking the Pill

• Take another pill as soon as possible, even if you feel uncomfortable 2
• Continue taking pills daily at the same time each day 2
• Use backup contraception (like condoms) or avoid sex until 2 days after vomiting has resolved 2
• Consider emergency contraception if you had unprotected sex 2

Critical timing note: POPs have a much narrower window than combined pills—a dose is considered missed if taken more than 3 hours late 2. This makes timing especially important with progestin-only pills 3.

For Emergency Contraceptive Pills (ECPs)

If Vomiting Occurs Within 2-3 Hours of Taking ECPs

• Take another dose of the emergency contraceptive pill as soon as possible 2, 1
• Consider using an antiemetic medication to prevent further vomiting 2

The FDA label for levonorgestrel emergency contraception specifically states to call a healthcare professional if you vomit within 2 hours to determine if you should repeat the dose 1.

Key Clinical Considerations

Why the 2-3 hour window matters: Peak serum steroid levels from oral contraceptives are reached about 2 hours after administration, followed by rapid distribution and elimination 2. If vomiting occurs before adequate absorption, contraceptive effectiveness may be compromised 2.

Common pitfall to avoid: Don't assume that brief vomiting within 24 hours requires redosing for combined oral contraceptives—the CDC guidelines specifically state redosing is unnecessary in this scenario 2. However, this is different for progestin-only pills and emergency contraception, where the 2-3 hour window applies 2, 1.

Antiemetic considerations: While routine antiemetic use before taking contraceptive pills is not recommended, meclizine has been shown to significantly reduce both nausea and vomiting when taken before combined estrogen-progestin emergency contraceptive pills 2, 4, 5. Metoclopramide reduces nausea severity but not vomiting rates 2, 4.