Plan B —also known as the “morning-after pill” —is a type of emergency contraception (EC).
It’s designed to be taken soon after unprotected penis-in-vagina sex to help prevent pregnancy.
Who can take it?Anyone who can become pregnant can take Plan B when needed —there isn’t an age restriction.
However, it isn’t regular contraception, so it should only be used in emergency situations.
For example:
- if you had sex without a barrier
- if the condom broke during sex
- if you forgot to take your birth control pill the day before or after sex
If taken within 72 hours of unprotected sex, this form of EC can reduce the chance of pregnancy by 75 to 89 percent.
According to Plan B’s manufacturer, the sooner you take the pill, the more effective it is.
Certain medications can alter its effectiveness.
If you take any of the following, speak with a healthcare professional before buying Plan B:
- rifampin (an antibiotic)
- griseofulvin (an antifungal)
- St. John’s wort (an herb)
- seizure medications, including carbamazepine, phenobarbital, and primidone
- some HIV medications, including efavirenz
Although the manufacturers advise taking Plan B within 3 days of unprotected sex, you can take it up to 5 days after penis-in-vagina sex.
Research has found that Plan B is “moderately effective” when taken between 72 and 120 hours after sex.
But remember that its effectiveness decreases the longer you wait.
Is there a weight limit?There’s no official weight limit for Plan B.
But the pill may not be as effective for people who have a BMI of 30 or moreTrusted Source or weigh 155 pounds or more.
After conflicting results, some researchers have recommended a greater level of counseling for people who fall into those two categories.
But they point out that there’s no reason to restrict Plan B.
More research is needed into whether a higher weight and BMI decreases the effectiveness of Plan B. For now, you’re free to take it, no matter how much you weigh.
However, other forms of EC (mentioned below) may be more effective.
How does it work?Plan B only works to prevent a pregnancy — it can’t end one.
It helps prevent pregnancy by using a bigger dose of levonorgestrel, the synthetic hormone found in birth control pills.
This mimics the natural hormone, progesterone, delaying the release of an egg from the ovary, thereby preventing ovulation.
If no egg has been released, there’s nothing for sperm to meet, and therefore no fertilization.
There’s been talk of Plan B also working to prevent a pregnancy after fertilization. But this is near impossible to prove, according to a 2019 review.
Are there any side effects or risks?Plan B is considered safe. Although it contains a higher hormone dose than birth control pills, the hormone doesn’t remain in the body for a long time.
Of course, you may experience mild side effects, including:
- headaches
- abdominal pain or cramps
- nausea or vomiting
- dizziness
- breast tenderness
Your menstrual cycle may also temporarily change.
This means your period could come earlier or later, and it could be heavier or lighter.
Some people even experience spotting in between periods, while some experience no change to their periods at all.
There isn’t much you can do to prevent these side effects.
But anti-nausea medicine and painkillers may help if you do experience any of the above.
If you vomit within 2 hours of taking this morning-after pill, speak with a healthcare professional to see if you need to take a second dose.
Remember that the biggest risk is that the morning-after pill fails. So, if your period is significantly late, take a pregnancy test.
It’s also wise to remember that you can become pregnant soon after taking Plan B, so ensure you use birth control before having penis-in-vagina sex again.
How much does it cost?Expect to pay between $40 and $50 for Plan B.
As Plan B is a branded form of EC, it tends to be more expensive. Generic levonorgestrel pills cost less and work in the exact same way.
There are other ways to reduce the cost.
If you have insurance or Medicaid, for example, you may be covered for some form of EC.
No insurance? You may be able to get EC for free or at a much lower cost at a family planning clinic or local health department.
Plan B’s manufacturer also has a coupon and rebate scheme. Get $10 off by printing out this coupon and taking it to a store that stocks Plan B.
Alternatively, if you’ve already bought the morning-after pill, you can upload a picture of your receipt online or mail it in for a rebate.
Where can you get it?Plan B is available over the counter at drugstores and pharmacies. So you don’t need a prescription or ID when buying it.
You may find it in the family planning aisle or need to ask the pharmacist to get it if it’s behind the counter.
Family planning clinics and local health departments, as well as Planned Parenthood centers, also offer the morning-after pill.
If you’d rather buy it online, you can buy directly from the manufacturer. Note that delivery takes around 4 to 6 days.
Stores like Walgreens and CVS also sell Plan B online.
Remember to always buy from a reputable retailer and try to buy in advance, as you can’t guarantee when it’ll be delivered.
What else should you know?Plan B isn’t the only form of EC out there.
Here’s the lowdown on other EC options, including how often you can use this form of contraception.
Are there other EC pills you can take?
Ella
If you’re looking for an EC pill that’s more effective longer after unprotected sex, consider Ella. It’s known as an ulipristal acetate pill. It works by delaying or preventing ovulation.
Most importantly, it is said to remain consistently effective when taken up to 5 days after unprotected sex, reducing the risk of pregnancy by 85 percent. It’s also more suitable for people with a higher BMI or weight. The only drawback is that you need a prescription to get hold of ella. Plus, it can be pricier than Plan B.
Copper IUDThere’s one other type of EC, but it doesn’t come in the form of a pill.
A copper intrauterine device (IUD) can be inserted into the uterus to prevent fertilization up to 5 days after unprotected sex.
It’s more than 99 percent effective if inserted within a 120-hour timeframe. Of course, you’ll need to book an appointment with a healthcare professional to get an IUD. But the best part is that you can use it as a regular form of birth control afterwards.
How often can you take EC?You can take Plan B and other levonorgestrel pills as often as you need them.
There are no long-term side effects.
But ella does have a limitation: The label says you should only take it once during a single menstrual cycle.
It’s also advised not to take two different kinds of EC pills within 5 days of each other, as there’s a risk that they may not work.
Is there a way to stock up on EC?It makes sense to buy EC pills in advance, so that you have it on hand if you ever need it.
Remember that the quicker you take some forms (like Plan B), the better they work.
You can stock up by purchasing in drugstores, pharmacies, or online — there are no restrictions.
Will EC affect your period?EC is known to affect the timing of people’s periods.
Some experience an earlier period, while others find theirs comes later.
You may also notice changes in heaviness or light spotting in between taking the pill and your next period.
There’s also a link between regularly taking EC and irregular periods.
So it’s always better to use regular birth control instead of relying on Plan B, ella, and the like.
Where can you learn more?There are lots of online resources packed with EC information and advice.
Take a look at the following:
References:
Appendices for U.S. medical eligibility criteria for contraceptive use. (2016).
cdc.gov/mmwr/volumes/65/rr/rr6503a1_appendix.htm
Emergency contraception. (2018).
who.int/en/news-room/fact-sheets/detail/emergency-contraception
Emergency contraception. (n.d.).
nyc.gov/site/doh/health/health-topics/teen-plan-b.page
Festin MPR, et al. (2017). Effect of BMI and body weight on pregnancy rates with LNG as emergency contraception: analysis of four WHO HRP studies.
contraceptionjournal.org/article/S0010-7824(16)30357-2/fulltext
Frequently asked questions. (n.d.).
planbonestep.com/faqs/
Is there a limit to the number of times I can use emergency contraceptive pills? (2020).
ec.princeton.edu/questions/ecrepeated.html
How Plan B works. (n.d.).
planbonestep.com/how-plan-b-works/
How often can you take the morning-after pill? What are the side effects? (2010).
plannedparenthood.org/learn/teens/ask-experts/how-often-can-you-take-the-morning-after-pill-what-are-the-side-effects
How often can you take the morning-after pill? (2021).
plannedparenthood.org/learn/teens/ask-experts/how-often-can-you-take-the-morning-after-pill
Kahlenborn C, et al. (2015). Mechanism of action of levonorgestrel emergency contraception.
journals.sagepub.com/doi/full/10.1179/2050854914Y.0000000026
Plan B One-Step (levonorgestrel) tablet. (2009).
accessdata.fda.gov/drugsatfda_docs/label/2009/021998lbl.pdf
Possible side effects. (n.d.).
planbonestep.com/plan-b-possible-side-effects/
Taking Plan B. (n.d.).
planbonestep.com/taking-plan-b/
Trussell J, et al. (2019). Emergency contraception: a last chance to prevent unintended pregnancy.
ec.princeton.edu/questions/EC-Review.pdf
Whalen K, et al. (2012). Ulipristal (ella) for emergency contraception.
aafp.org/afp/2012/0815/p365.html
What’s the Plan B morning-after pill? (n.d.).
plannedparenthood.org/learn/morning-after-pill-emergency-contraception/whats-plan-b-morning-after-pill
What’s the ella morning-after pill? (n.d.).
plannedparenthood.org/learn/morning-after-pill-emergency-contraception/whats-ella-morning-after-pill
When would I use ella instead of progestin-only EC (like Plan B One-Step, Next Choice One Dose, or Take Action)? (2020).
ec.princeton.edu/questions/ella-vs-levo.html
Which kind of emergency contraception should I use? (n.d.).
plannedparenthood.org/learn/morning-after-pill-emergency-contraception/which-kind-emergency-contraception-should-i-use
Written by Lauren Sharkey on April 15, 2021
https://www.healthline.com/reviewers/valinda-riggins-nwadike-md-mph