What is the proper way to take emergency contraception after unprotected sex?

Emergency Contraception Administration Guidelines

Emergency contraception should be taken as soon as possible within 5 days (120 hours) of unprotected sexual intercourse to maximize effectiveness, with copper IUDs being the most effective option, followed by ulipristal acetate, then levonorgestrel. 1, 2

Available Emergency Contraception Options

• Copper Intrauterine Device (Cu-IUD):

  • Can be inserted within 5 days of unprotected intercourse as the most effective emergency contraceptive option 2
  • Provides ongoing contraception after insertion 2

• Ulipristal Acetate (UPA):

  • Single 30 mg dose effective up to 5 days (120 hours) after unprotected sex 1, 3
  • More effective than levonorgestrel when taken 3-5 days after unprotected sex 1
  • May be more effective for women who are overweight or obese compared to levonorgestrel 1, 3

• Levonorgestrel:

  • Can be taken as a single 1.5 mg dose or as two 0.75 mg doses 12 hours apart 1, 4
  • Most effective when taken within 72 hours, with decreased effectiveness after this timepoint 1, 5

• Combined Estrogen and Progestin:

  • Two-dose regimen (100 μg ethinyl estradiol plus 0.50 mg levonorgestrel per dose, taken 12 hours apart) 1
  • Less effective than UPA or levonorgestrel with more side effects (nausea and vomiting) 1

Timing and Administration Protocol

For Copper IUD:

• Insert within 5 days of the first act of unprotected sexual intercourse 1
• Can be inserted beyond 5 days if the day of ovulation can be estimated, as long as insertion does not occur >5 days after ovulation 1

For Ulipristal Acetate (UPA):

1. Take a single 30 mg dose as soon as possible within 120 hours of unprotected intercourse 3
2. After taking UPA, any regular contraceptive method can be started immediately 1
3. Use barrier contraception or abstain from sexual intercourse for 14 days or until next menses, whichever comes first 1, 3
4. Take a pregnancy test if no withdrawal bleed occurs within 3 weeks 1

For Levonorgestrel:

1. Take a single 1.5 mg dose or two 0.75 mg doses 12 hours apart as soon as possible within 72 hours of unprotected intercourse 1, 5
2. After taking levonorgestrel, any regular contraceptive method can be started immediately 1
3. Use barrier contraception or abstain from sexual intercourse for 7 days 1
4. Take a pregnancy test if no withdrawal bleed occurs within 3 weeks 1

For Combined Estrogen and Progestin:

1. Take first dose (100 μg ethinyl estradiol plus 0.50 mg levonorgestrel) as soon as possible 1
2. Take second identical dose 12 hours later 1
3. After taking combined ECPs, any regular contraceptive method can be started immediately 1
4. Use barrier contraception or abstain from sexual intercourse for 7 days 1
5. Take a pregnancy test if no withdrawal bleed occurs within 3 weeks 1

Special Considerations

• Vomiting: If vomiting occurs within 3 hours of taking any oral emergency contraceptive, take another dose as soon as possible 1

• Effectiveness by Timing: All emergency contraception methods are more effective the sooner they are used after unprotected intercourse 4

• BMI Considerations: For women with BMI > 30 kg/m², ulipristal acetate may be more effective than levonorgestrel, though both may have reduced efficacy 3, 6

• Advance Provision: Providing emergency contraception in advance may increase the likelihood of timely use when needed 2, 7

Comparative Effectiveness

• Cu-IUD is the most effective emergency contraception method (nearly 100% effective) 2, 8
• Ulipristal acetate maintains effectiveness throughout the full 120-hour window 2, 6
• Levonorgestrel shows significantly reduced effectiveness after 72 hours 1, 7
• Combined estrogen-progestin regimens are least effective and have more side effects 1

By following these guidelines, emergency contraception can effectively prevent unintended pregnancy after unprotected sexual intercourse or contraceptive failure. Remember that emergency contraception should not replace regular contraceptive methods but serve as a backup option 7.