Does starting the mini pill (progestin-only pill) more than 24 hours after unprotected sex prevent pregnancy?

Starting the Mini Pill After Unprotected Sex Does Not Prevent Pregnancy

Starting the progestin-only pill (mini pill) more than 24 hours after unprotected sex will not prevent pregnancy and emergency contraception should be considered instead.

Understanding the Mini Pill and Emergency Contraception

The mini pill (progestin-only pill) is designed for ongoing contraception, not for emergency use after unprotected intercourse. Here's why it doesn't work as emergency contraception:

• The mini pill requires at least 48 hours of consistent use to achieve contraceptive effects, primarily through thickening cervical mucus 1
• It takes approximately 7 consecutive days of hormonal contraceptive use to reliably prevent ovulation 2
• When starting any hormonal contraceptive method, backup contraception or abstinence is needed for the first 2-7 days (depending on the method) 1

What to Do After Unprotected Sex

If more than 24 hours have passed since unprotected intercourse:

1. Use emergency contraception immediately:

   • Emergency contraceptive pills (ECPs) should be taken as soon as possible within 5 days of unprotected intercourse 1
   • Options include:
     • Ulipristal acetate (30 mg single dose) - most effective option, especially after 72 hours 1, 3
     • Levonorgestrel (1.5 mg single dose) - available over-the-counter 1, 3
     • Copper IUD insertion - most effective overall method, can be inserted up to 5 days after unprotected sex 1, 4

2. Then start regular contraception:

   • The mini pill can be started immediately after using emergency contraception 2
   • Use backup contraception (condoms) or avoid intercourse for 2 days after starting the mini pill 1

Effectiveness Considerations

• Emergency contraception effectiveness decreases with time - the sooner it's taken, the more effective it is 3
• Copper IUDs are the most effective emergency contraception method (>99% effective) 4
• Ulipristal acetate is more effective than levonorgestrel, especially 3-5 days after unprotected sex 1
• Levonorgestrel ECPs reduce pregnancy risk by approximately 75% 5
• Mini pills started after unprotected sex will not prevent pregnancy from that specific encounter 1

Common Pitfalls to Avoid

• Don't confuse regular contraception with emergency contraception - they serve different purposes and have different timing requirements 1, 2
• Don't delay seeking emergency contraception - effectiveness decreases with time 3
• Don't skip using backup contraception when starting hormonal methods like the mini pill 1
• Don't assume the mini pill provides immediate protection - it takes time to establish contraceptive effect 1
• Don't forget that emergency contraception is not as effective as regular contraception - establish a reliable ongoing method 6

Remember that emergency contraception should not be considered an alternative to consistent contraceptive use but can prevent unwanted pregnancy when used promptly after unprotected intercourse 5, 7.