But if you've never taken emergency contraception before, you might be wondering: Does this stuff have any side effects?
“Plan B contains a type of progesterone, the same steroid hormone that’s in oral contraceptives, but at a higher dose,” says Iffath Hoskins, M.D., clinical associate professor in the department of obstetrics and gynecology at NYU Langone Health. “It works by one or all of the following ways: delaying ovulation, preventing fertilization, and/or preventing egg implantation.” (Reminder: Plan B is not the abortion pill. It prevents pregnancy from occurring in the first place; it does not terminate an existing pregnancy.)
Though Plan B is generally considered very safe (especially compared to an unplanned pregnancy. ), that high dose of progesterone may cause a few potential side effects.
Here's are the Plan B side effects you should know about:
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Taking Plan B can cause your period to be lighter or heavier, or arrive earlier or come late. “These side effects are due to the high-dose progesterone acting on the lining of the uterus at variable points in time during the menstrual cycle,” says Hoskins.
How it affects your cycle depends on where exactly you are in your cycle when you take it. And while it may cause changes, “these are always temporary, especially when the pill is used correctly, i.e. very rarely/occasionally and not regularly and repeatedly,” she says.
Your next period should be normal, and come at the expected time, or within a week of the expected time.
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One unpleasant side effect of the morning-after pill is that queasy, upset-stomach feeling. “Again, this is due to the pill having a high dose of progesterone,” says Hoskins.
That extra influx of hormones can throw your body out of whack for a bit, until it gets used to the higher level. “In general, it’s mild to moderate but like most everything else in medicine, there may be a few instances of severe, unremitting nausea and vomiting. In those cases, you should seek medical attention,” she says.
Also, if you throw up within two hours of taking Plan B, the medication may not have been fully absorbed into you system. You should call your doctor to see if you need to repeat the dose.
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If you’re feeling lightheaded or dizzy after taking Plan B, don’t immediately freak out. “The usual underlying cause here is that progesterone causes relaxation of the muscle cells in the blood vessels; therefore, the blood tends to pool in the blood vessels of the lower extremities, resulting in less blood flowing to the head,” says Hoskins. “That can cause dizziness and lightheadedness.” Again, this should be temporary, so if it’s persistent, call your doc.
