Plan B

All You Need To Know About Plan B One-Step®

What It Is & How It Works

  • Plan B One-Step® is a single-dose, progestin-only emergency contraceptive tablet (levonorgestrel 1.5 mg)
  • Currently the only morning-after pill approved for use in women of any age without a prescription
  •  Shown to be both safe and effective in women of all ages
  • Works like regular birth control to help prevent pregnancy after birth control failure or unprotected sex by preventing ovulation, preventing fertilization, and inhibiting implantation
  • The single-dose pill is designed to prevent pregnancy and will not be effective once the implantation process has begun.
  •  Plan B One-Step® is not the same as RU-486 (the abortion pill) and will not affect an existing pregnancy or cause any harm to a developing fetus
  •  If you have any additional questions or concerns, please do not hesitate to consult with the pharmacy staff. We would be happy to answer any and all questions you may have.

Who Should Not Take This Pill?

Plan B One-Step® should not be taken:

  • To protect against HIV or STDs (this product does not protect against these diseases)
  • To replace regular birth control (Plan B One-Step® should only be used as a backup, emergency method of contraception. It is not as effective as routine birth control)
  • In those who have a known allergy to levonorgestrel or any ingredient in Plan B One-Step®
  • In those who are already pregnant (it will not harm the fetus, but it will be ineffective)
  • In individuals who consistently take birth control correctly, but your partner’s condom slipped or broke

When To Consult The Pharmacist

Refer to the pharmacy staff before using this product if:

  • It has been greater than 72 hours since unprotected intercourse or contraceptive failure
  • You vomit within 2 hours of taking this product (extremely rare)
  • You have recently taken or are currently taking rifampin
  • You have missed doses of your regular birth control

What Are The Possible Side Effects?

Some women may experience mild side effects similar to those experienced from regular birth control pills, including:

  • Headache
  • Changes in your period
  • Nausea (If vomiting occurs within two hours of taking the tablet, please consult the pharmacist to determine if a second dose should be taken)
  • Lower abdominal pain
  • Fatigue
  • Dizziness
  • Breast tenderness

Additionally, some women may experience menstrual changes such as spotting or bleeding before their next period.

Some women may have a heavier or lighter next period, or a period that is early or late depending on when the pill is taken during your cycle.

The majority of women have their menstrual period at the expected time or within ±7 days.

The only way of knowing that Plan B One-Step® has worked is when you get your next period, which should come at the expected time or within a week of the expected time. If your period is more than one week late, you should receive a pregnancy test, as you may be pregnant.

When To Take Plan B One-Step®

  • Taking Plan B One-Step® before having unprotected intercourse or contraceptive failure will not protect a woman from getting pregnant
  • Plan B One-Step® is most effective in the first 72 hours after unprotected intercourse or contraceptive failure (e.g. your partner’s condom broke or slipped, or you forgot to take your regular birth control pills).
  • When taken as directed, approximately seven out of eight women who would have gotten pregnant will not become pregnant.
  • You should resume your regular method of contraception as soon as possible as Plan B One-Step® is not designed to replace regular birth control.

If it has been longer than 72 hours since unprotected intercourse or contraceptive failure, please consult the pharmacy staff before using this product to determine if the pill should still be used.

If you have missed doses of your regular birth control, please consult the pharmacy staff to determine your need for the product and develop a plan to restart your regular birth control regimen.

Additional Resources

University Health Services Women’s Clinic
333 E Campus Mall | (608) 265-5600
(Free pregnancy testing for UW students)

Planned Parenthood
2222 S Park Street | (608) 251-6546

Plan B One-Step® Information Center