Does Plan B make you bleed? What to know about emergency contraception

In this article:

• How does Plan B work?
• Is it normal to bleed after taking Plan B?
• How long does Plan B bleeding last?
• Other Plan B side effects
• Where can I get Plan B?
• When to see a doctor for Plan B bleeding

In this article

• How does Plan B work?
• Is it normal to bleed after taking Plan B?
• How long does Plan B bleeding last?
• Other Plan B side effects
• Where can I get Plan B?
• When to see a doctor for Plan B bleeding

Plan B One-Step, also referred to as Plan B, is a type of emergency contraception (EC) pill, or emergency birth control. Plan B is commonly referred to as the morning-after pill. It can be used for pregnancy prevention after unprotected sex or a birth control failure, such as:

• If a condom breaks during sex
• If a diaphragm slides out of place
• If you forget to take one or more birth control pills
• If you do not use any birth control during sexual intercourse
• If you use birth control incorrectly (for example, not taking pills consistently every day at the same time each day)
• If you have been raped or sexually assaulted

The active ingredient in Plan B is levonorgestrel, a synthetic progesterone hormone. When taken as directed, Plan B is effective in reducing the risk of unplanned pregnancy. It is also well-tolerated and is generally associated with some mild—but not serious—side effects. 

After you take Plan B, you may experience some spotting or bleeding. You may also notice changes to your next period—for example, your period may arrive earlier or later, or the bleeding may be lighter or heavier. Continue reading to learn more about Plan B.

How does Plan B work?

Plan B contains a progesterone hormone (a female hormone that’s involved in pregnancy and menstruation) called levonorgestrel. As an EC pill, the way Plan B works is by delaying or preventing ovulation. Ovulation is the time in your menstrual cycle, which is generally midcycle, when an egg is released from the ovary, travels down the fallopian tube, and is prepared to be fertilized and start a pregnancy. Plan B only works if you have not yet ovulated. It does not work if you have already ovulated or if you are already pregnant. 

Plan B is a very effective type of EC. Levonorgestrel morning-after pills such as Plan B, Take Action, Aftera, My Way, My Choice, and EContra One-Step are most effective when taken as quickly as possible after unprotected sex or birth control failure. The sooner you take Plan B, the better the chances are that it will work. Taking Plan B within three days (72 hours) of unprotected sex can lower the chance of pregnancy by up to 89%. However, Plan B can still work up to five days, or 120 hours, after unprotected sex or birth control failure—but is not as effective as if you take it sooner.

There can be some confusion about what Plan B is and is not. Although it can be used as an EC to prevent pregnancy, it is important to know the following:

• Plan B is not an abortion pill.
• Plan B does not work if you are pregnant.
• Plan B does not offer protection against sexually transmitted infections, such as HIV.
• Plan B is not intended for use as a regular form of birth control.

Is it normal to bleed after taking Plan B?

Yes, it is normal for Plan B to possibly cause some spotting or breakthrough bleeding. It may also affect your next period, which may be earlier or delayed. When you get your next period, the length and type of bleeding may also be different than normal. For example, your period may be shorter or longer, or it may be more spotty, or it may be heavier or lighter. Note, however, that if you are one week (or more) past the expected start date for your period and do not yet have your period, you should take a home pregnancy test (or visit a healthcare provider’s office) to find out whether you are pregnant. 

Also important to note is that there are some possible drug interactions that could lead to spotting and breakthrough bleeding. Certain drugs affect how Plan B is processed in the body, which could cause breakthrough bleeding or even result in Plan B being less effective, which could lead to unintended pregnancy. Examples of these drugs include:

• Barbiturates such as phenobarbital 
• Other anticonvulsant medications, including Tegretol (carbamazepine), Dilantin (phenytoin), Topamax (topiramate), and Trileptal (oxcarbazepine)
• Certain medications used to treat HIV 
• Griseofulvin
• Rifampin 
• St. John’s wort (supplement)
• Tracleer (bosentan)

It is a good idea to talk to a healthcare provider before the need for EC may arise, especially if you take one of the medications listed above. Your healthcare provider can advise you on the best type of EC and start you on a regular form of effective birth control. 

How long does Plan B bleeding last?

After taking Plan B, you may have some temporary spotting or breakthrough bleeding. Then, your next period may be irregular. For example, it may be:

• Shorter than usual
• Longer than usual
• Later than usual
• Earlier than usual
• Heavier than usual
• Lighter or spottier than usual

One study noted that about 15% of women who took Plan B had spotting and an irregular period but that most menstrual changes disappear after the first period following a dose of Plan B and return to normal the following month. 

However, although it is safe to take Plan B more than once in a menstrual cycle, using EC often may lead to irregular bleeding (as well as more side effects). There are many forms of birth control that are more effective when used consistently and correctly. Talk to your healthcare professional about which type of birth control is right for you. 

Other Plan B side effects

In addition to bleeding and temporary menstrual cycle irregularities, you may notice some other mild common side effects from Plan B, such as:

• Headache
• Dizziness or lightheadedness
• Tiredness
• Breast tenderness
• Upset stomach, nausea, and vomiting (If you vomit within two hours of taking Plan B, ask your healthcare provider if you should take another dose.)

There aren’t any serious side effects associated with Plan B. 

Where can I get Plan B?

Currently, anyone can get Plan B. You do not need a prescription, and you do not have to present identification. People of any age or gender can purchase Plan B over the counter at a pharmacy. Ask your pharmacist if you don’t see it on the shelf since some pharmacies keep it behind the counter. You can also ask your pharmacist any questions you may have about taking Plan B. 

Other places you may find Plan B include your local health department, family planning clinic, and Planned Parenthood locations. 

When to see a doctor for Plan B bleeding

You should check in with a healthcare provider for medical advice if your period is irregular after one month or if you have long-lasting or heavy bleeding, other symptoms like dizziness or weakness, or any other severe or concerning symptoms.

Also, if you have symptoms of severe abdominal pain three to five weeks after taking Plan B, this could be a sign of ectopic pregnancy (a pregnancy that occurs outside of the uterus, usually in a fallopian tube). See your doctor for immediate medical attention if you suspect ectopic pregnancy.