What to expect from Plan B®
When did you have sex
without a contraceptive or have a contraceptive accident?
Plan B® is effective
Although few women experience vomiting with Plan B®, if you vomit within two hours of taking Plan B®, you might not have absorbed the medication contained in the pill. Call your healthcare professional, as you might need another dose.
After you’ve taken Plan B®, you should get your next period at the expected time, or a few days early or late. You may experience spotting a few days after taking Plan B®, but this is not your period.
While you’re waiting for your next period, abstain from having unprotected intercourse or make sure to use a contraceptive.
If you’ve taken Plan B® because of missed birth control pills, start your birth control pills right away and remember to use another method of contraception, such as condoms, until your birth control is fully reliable again.
Side effects of the morning-after pill
It’s very unlikely that you will have any severe reactions to Plan B®. You may have some temporary side effects that will usually pass within 24 hours.
Most common Plan B® side effects
Like all medications, Plan B® can cause some side effects:
- Nausea: ~14% to 23% of women
- Abdominal pain: ~18% of women
- Fatigue: ~17% of women
- Headache: ~17% of women
- Dizziness: ~11% of women
- Breast tenderness: ~11% of women
- Vomiting: ~6% of women
- Diarrhea: ~5% of women
- Irregular menstrual bleeding: Some women may experience spotting after taking Plan B®. The majority of women will have their next menstrual period at the expected time or early. When Plan B® is used repeatedly (more than once in a menstrual cycle, or more than occasional once-a-month use), menstrual changes may occur, including a shorter or longer cycle and a heavier or lighter period than normal.
These side effects usually do not last more than 24 hours.
Less common Plan B® side effects
Migraine or severe headache, lower abdominal pain, painful menstruation and vaginal discharge. If your period is more than a week late or if the symptoms persist for more than 48 hours or are severe, see your healthcare professional.
Unusual side effects—call a healthcare professional immediately
- Itching and a rash
- Sudden or unusual cramping or severe pain in your stomach or belly prior to your next normal period
- Uterine hemorrhage
- Vaginal hemorrhage
- Any effects that persist or worsen
- If you vomit within two hours of taking Plan B®, you may need to take another dose
Some medications can interact with Plan B® and make it less effective. These include anti-HIV drugs (efavirenz and ritonavir), anticonvulsant drugs (phenytoin, carbamazepine, primidone and phenobarbital), antibiotics (ampicillin, cotrimoxazole, tetracycline, temafloxacin, and clarithromycin), rifampicin, rifabutin, griseofulvin, St. John’s wort, and ulipristal acetate.
There are some medical conditions that may mean Plan B® is not right for you. Plan B® is not recommended if:
- You have a confirmed or suspected pregnancy
- You are allergic to levonorgestrel, or to any of the ingredients in the formulation
- You have abnormal vaginal bleeding
For more details, download the abbreviated Plan B® Product Monograph (Part III):Product Monograph (Part III): Plan B® 1.5 mg