How does it work?
Emergency contraception (the morning after pill) works primarily by delaying or inhibiting ovulation (the process by which an egg matures and is released). In addition, emergency contraception may disrupt fertilization (the joining of the egg and sperm) or possibly inhibit implantation (the planting of the fertilized egg into the womb). Emergency contraception is not effective if a woman is already pregnant, as it cannot terminate an existing pregnancy.
How well does it work?
If it is taken within 3 days (72 hours) after unprotected sex, emergency contraception will decrease the chance that you will get pregnant by up to 89%. On average, if 100 women have unprotected sex once during the second or third week of their cycle, 8 will become pregnant. Following treatment with emergency contraception, only 1 or 2 will become pregnant. Although it is less effective if taken after 3 days, studies have shown that emergency contraception may still reduce your risk of pregnancy when it is taken up to 5 days (120 hours) after unprotected sex. In the US, it is estimated that emergency contraception could prevent 1.7 million unintended pregnancies every year.
What are the potential side effects?
The most common side effects of emergency contraception are nausea and vomiting. These side effects are much more common with Lo/Ovral, or the generic equivalent Low-Ogestrel, than with Plan B. About 50% of women who take Lo/Ovral experience nausea and 20% vomit. The over-the-counter anti-nausea medicine meclizine will reduce the risk of nausea and vomiting when two 25 mg tablets are taken one hour before the first dose of Lo/Ovral. The risk of nausea and vomiting with Plan B is far lower than the risk with Lo/Ovral: 23% experience nausea and only 6% vomit. We encourage Lo/Ovral users to take meclizine prior to their first dose. Because the risk of vomiting is very low with Plan B, we do not routinely recommend that Plan B users take meclizine. If you vomit within one hour after taking either dose of emergency contraception, please contact our on-call physician at doctor@getthepill.com to discuss whether or not to repeat the dose.
Other side effects include abdominal pain, fatigue, headache, dizziness, and breast tenderness. Side effects usually subside within a day or two after treatment is completed.
Is emergency contraception right for me?
Emergency contraception should be used if a woman has had recent unprotected sex, has been the victim of a sexual assault, or suspects that her regular contraceptive method has failed, such as a condom breaking.
For whom is emergency contraception not the right choice?
The only absolute contraindication to use of emergency contraception is pregnancy, not because it will cause any harm to a pregnancy, but simply because it will not work if a woman is pregnant.
How do I use emergency contraception?
Plan B
If the pharmacist dispenses Plan B to you, the pack will contain 2 pills. The instructions on the Plan B pack may direct you to take the first pill as soon as possible followed by the second pill twelve hours later. However, research has shown that the Plan B pills are just as effective regardless of whether the two pills are taken at the same time or taken twelve hours apart. Therefore, for ease of use, we recommend that you take both pills at the same time as soon as possible.
Lo/Ovral, or the generic equivalent Low-Ogestrel
If the pharmacist dispenses Lo/Ovral, or the generic equivalent Low-Ogestrel, the pack will contain 28 pills. Please take the first 4 pills as soon as possible followed by the next 4 pills twelve hours later. Please keep the next 13 pills (pills #9-21) for future emergency contraception needs. Please discard the last 7 pills (pills #22-28) as they contain no hormones and cannot be used for emergency contraception.
Important things to know about emergency contraception
-- Emergency contraception provides NO PROTECTION AGAINST (or treatment for) sexually transmitted diseases including HIV (the virus that causes AIDS). If used correctly every time that you have sex, latex condoms will help reduce the risk of infection with HIV and other sexually transmitted diseases.
-- Emergency contraception is INTENDED FOR EMERGENCY USE ONLY and should never take the place of a regular method of birth control. There are more effective methods of birth control that should be used on a regular basis to prevent pregnancy.
-- Your next period may arrive a few days earlier or later than usual.
-- EMERGENCY CONTRACEPTION CAN FAIL. You should perform a home pregnancy test if your next period is delayed by more than one week.
If you have additional questions that have not been answered above, please visit the following link for a more extensive list of frequently asked questions: http://ec.princeton.edu/questions/index.html
