Does Plan B cause infertility?

The best reliable sources of online health information related to drug side effects include the FDA and MedlinePlus. We are also here to answer your specific questions, and are happy you found EmpowHer to ask these important questions!

Since it sounds like my short answers above were not sufficient, let me lather on the data and information, as it's great that you want to learn more!

When looking for information on Plan B, you can find more information with looking for the actual drug, which is the hormone levonorgestrel. This is in both Plan B and Plan B One-Step in the United States. Plan B is given in two doses of 0.75 mg tablets, whereas Plan B One-Step is given in a one dose 1.25 mg tablet.

The questions & answers mentioned above related to Plan B use:
1. Is it safe?
There are no known long-term or serious side effects from Plan B use, when used as directed as a temporary form of pregnancy prevention. See below for more information on side effects. The hormone levonorgestrel is higher than in a single birth control pill, and has been used in birth control pills for over 30 years.

2. How often can I use it?
Plan B is not recommended for routine use as a contraceptive, as the failure rate is relatively high compared to routine contraception. Please know that Plan B is a highly effective temporary method of contraception, but the continued use of it overtime has not been studied (the higher dose of progesterone may have side effects).
In other words: "Plan B should not be used as a regular birth control method. It does not work as well as most other forms of birth control when they are used consistently and correctly. Plan B is a backup or emergency method of contraception." It is basically a "last chance" to prevent pregnancy after unprotected sex, and the BEST method is to have PROTECTED sex with using birth control pills and/or condoms.

3. What are the side effects (short and long term?)
Short-Term Side Effects
May include: nausea, vomiting, abdominal pain, fatigue, dizziness, menstrual changes and headache. These side effects usually disappear after 1-2 days. About 25% of women who take progestin-only pill (Plan B) experience nausea.

You may be interested to know that according to the June 2009 emergency contraception review paper (source below), "The original treatment schedule [of Plan B] was one 0.75 mg dose within 72 hours after unprotected intercourse, and a second 0.75 mg dose 12 hours after the first dose. However, recent studies have shown that a single dose of 1.5 mg is as effective as two 0.75 mg doses 12 hours apart." In laymen terms, this is the difference between Plan B (two 0.75 mg doses) vs. Plan B One-Step (one 1.25 mg dose), and can be taken up to 120 hours after unprotected intercourse. However, the sooner you take it (minutes versus days after), the more effective it is.

"One of the studies showed no difference in side effects between the two regimens, while the other found greater levels of headache and breast tenderness (but not other side effects) among study participants taking 1.5 mg of levonorgestrel at once."

Long-Term Side Effects
There are no long-term or serious side effects with Plan B for most women; some women with a family history of liver disease, blood clots or other conditions should speak to their doctor before taking this medicine, as it may increase their risks.

4. Does Plan B cause infertility?
Plan B ("emergency contraception") does not prevent future pregnancies, does not cause infertility, and is less effective than other methods of birth control. This is why oral contraceptives are recommended for use to prevent pregnancy, as they are 99% effective (compared to Plan B, which in most studies have been shown to "prevent about 74% of expected pregnancies"). Condoms, when used consistently and correctly, can be up to 98% effective at preventing pregnancy, so this should be the first "back-up" method of choice.

Lastly, if you are taking your birth control pills each and every day, consistently and correctly (same time each day), they are 99% or more effective at preventing pregnancy. If you continue to worry about pregnancy, use a condom to "double-up", as Plan B is not as effective as birth control or condoms.

Additional Resources:
- ]]>Emergency Contraception: Not-2-Late]]>
- Trussel, J. & Raymond, E.G. (June 2009). Emergency Contraception: A Last Chance to Prevent Unintended Pregnancy. Retrieved August 27, 2009 at the Emergency Contraception Website, Princeton University: http://ec.princeton.edu/questions/ecsideeffects.html
- Planned Parenthood

I hope this information helps--please let us know if you have any other questions!

I couldn't tell you what too much is, but it would be safer for you not to rely on it as occasional backup. You can call a local pharmacy and speak with a pharmacist who will be able to tell you more information on side effects ,or research it on google. If i find out more information myself, I will definitely post back and let you know. :)

how much is too much? and what are the long term side effects?

taking too much plan B is definitely not good for you (i work at a pharmacy). plan B is a dose of birth control x 3. it is meant for emergency situations. if you are taking the pill everyday, you do not need to take plan B. if you are still paranoid, use a condom.

oh thats the question that I saw! I would like to know that too. People say it does.

Annonymous (love the user name!),

No, Plan B does not cause infertility. The drugs in Plan B are the same hormones that are found in many types of birth control, just at a higher dose. Plan B also does not terminate an existing pregnancy; same as birth control pills.

You would only need to take Plan B if you missed pills, while on the birth control pill, not as a double back-up...that is a lot of hormones in your system that could cause changes in your period, or spotting in-between periods.