Plan B Warnings and Precautions

Before taking Plan B, warnings and precautions for the drug should be fully understood. For instance, you should be aware that Plan B is significantly less effective (and significantly more expensive) than many other forms of birth control. You should talk to your healthcare provider if you have diabetes or any allergies before taking Plan B. Warnings and precautions also apply to women who are pregnant or breastfeeding.

Plan B: What Should I Tell My Healthcare Provider?

You should talk with your healthcare provider prior to using Plan B One-Step™ (levonorgestrel) if you:
  • Have diabetes
  • Are pregnant or suspect that you may be pregnant
  • Are breastfeeding
  • Have any allergies, including allergies to foods, dyes, or preservatives.
Also, make sure to tell your healthcare provider about any other medications you are taking, including prescription and non-prescription medicines, vitamins, and herbal supplements.

Specific Plan B Warnings and Precautions

Some of the warnings and precautions to be aware of prior to using Plan B include the following:
  • The medication is not meant to be your main form of birth control. It is significantly less effective (and significantly more expensive) than many other forms of birth control.
  • Plan B is not effective at terminating an established pregnancy. This means that the drug will not cause an abortion if a fertilized egg has already implanted in your uterus.
  • Your period may be different after you take Plan B. Some women experience spotting (light vaginal bleeding) a few days after taking it. Most women have a normal period after taking Plan B, although some women will have lighter or heavier periods.
  • If your period is more than a week late, you may be pregnant and should consider taking a pregnancy test.
  • Plan B does not protect against sexually transmitted diseases (STDs), including HIV or AIDS.
  • Plan B may increase blood sugar levels in women with diabetes. Usually, this does not require a change in insulin dose. However, you should monitor your blood glucose as you normally do.
  • Fertility usually returns to normal rather quickly after taking Plan B. Although the drug can help prevent pregnancy after unprotected intercourse, it will not prevent a future pregnancy, unless you take it again after unprotected sex.
  • Progestin-only contraceptives (including Plan B) may increase the risk of ectopic pregnancy (pregnancy outside of the uterus, including "tubal" pregnancy). This is a dangerous and potentially life-threatening problem. If you develop severe lower abdominal pain (stomach pain), especially if your period is late, tell your healthcare provider immediately. However, if you have had an ectopic pregnancy in the past, this does not mean that you cannot take Plan B.
  • Plan B may, theoretically, interact with other medications (see Plan B Drug Interactions).
  • Plan B is considered a pregnancy Category X medication. This means that it should not be used during pregnancy (see Plan B and Pregnancy).
  • Contraceptive hormones, such as the one in Plan B, do pass through breast milk. Therefore, if you are breastfeeding or plan to start, discuss this with your healthcare provider prior to taking the drug (see Plan B and Breastfeeding).
Last reviewed by: Kristi Monson, PharmD
Feed Your Adult ADHD Brain