Levonorgestrel is one of the longest-studied types of progestin which is the synthetic version of progesterone, a hormone made by the body. And all the scientific evidence to date shows it is super safe. It’s used in hormonal IUDs, some emergency contraception pills, and certain birth control pills.
Birth control pill

What is levonorgestrel?
Is it safe to take the pill for years without a break?
There’s been lots of research on birth control pills over the years and the consensus is that long-term use doesn’t affect your ability to get pregnant once you stop taking the pill. It’s always a good idea to stay current on your annual health exams, whether you use the pill or another method. Our health changes over time, and some changes like rising blood pressure or worsening migraines may make it risky to use methods with estrogen, which is in the combination pill. If you have a new or worsening health condition, talk to a health care provider to make sure the pill is still safe for you.
The short answer is yes—there’s no reason to take a break from the pill unless you’ve decided you want to get pregnant or switch to another method. That’s true for continuous use of the pill too—although if you experience bothersome unexpected bleeding or spotting, you may want to take an occasional break (3-7 days) to manage it. If you take a break for more than 7 days, you’ll need to use a backup method, like condoms, for 7 days after you restart your pills.
There’s been lots of research on birth control pills over the years and the consensus is that long-term use doesn’t affect your ability to get pregnant once you stop taking the pill. It’s always a good idea to stay current on your annual health exams, whether you use the pill or another method. Our health changes over time, and some changes like rising blood pressure or worsening migraines may make it risky to use methods with estrogen, which is in the combination pill. If you have a new or worsening health condition, talk to a health care provider to make sure the pill is still safe for you.
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What if I want to start taking my pill at a different time?
Yes, it’s okay to switch what time of day you take your pills but depending on the type of pill you are taking (combination or progestin-only pill) and if you are switching to a later time or an earlier time in the day, you might need a backup method of birth control after switching times. If you move the time earlier in the day (i.e. from afternoon to morning), it will be less than 24 hours between pills, so go ahead and switch the time—you don’t need a backup method for either type of pill.
If you want to switch to later in the day and you’re taking the combination pill (the most common type of pill) (the most common type), go ahead and switch the time since the time of day you take your pills doesn’t matter for them to work as birth control (but taking them at a consistent time can help you remember to take them every day). If it’s been 48 hours or more since you took your last pill, you’ll need to use a backup birth control method if you have sex for the first seven days after restarting.
If you want to switch to later in the day and you’re taking the progestin-only, mini-pill (other than Slynd, you don’t need to use a backup method if the new time is less than three hours after your original time. (For example, you were taking it at 7pm and now you are going to take it at 9pm). If the new time is more than three hours after the old time, then you’ll need to treat it as a missed pill and use a backup method, like condoms or internal condoms if you have sex for the first two days after switching the time.
Is the pill bad for the environment?
Hormones in birth control can get into the environment through pee. But—and this is a big but—it is small compared to other sources of estrogen. Current research finds that the contribution of EE2 (the primary active ingredient in the pill, ring, and patch) to the total amount of estrogen in of our environment is small. Bigger—much bigger—sources of estrogen in the environment come from industrial and manufacturing processes, agricultural fertilizers and pesticides, the drugs we give livestock. and the waste and runoff produced by these sources. Avoiding birth control with estrogen hormones will not eliminate the environmental impacts of estrogenic compounds.
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What birth control methods are safe for people who just gave birth?
Birth control methods with no hormones, like the non-hormonal IUD, condoms, sterilization, lactational amenorrhea[RW5] , and hormonal methods that don’t contain estrogen—the shot, hormonal IUDs, the implant and the mini-pill—are all safe to use immediately after giving birth. Combination pills, the ring, and the patch, which contain estrogen, shouldn’t be used until three weeks after giving birth, since estrogen and being postpartum both increase the risk of blood clots.
Can the pill help protect you from ovarian cancer?
The pill offered the strongest protection from ovarian cancer when used for a year or longer. People who used the pill for 10 years were 50% less likely to develop ovarian cancer. The pill’s protective effect lasted for a long time, too—up to 20 years after people stopped taking it.
Yes. Research shows that people with ovaries who had ever used the pill for birth control were 25% less likely to develop ovarian cancer later in their lives.
The pill offered the strongest protection from ovarian cancer when used for a year or longer. People who used the pill for 10 years were 50% less likely to develop ovarian cancer. The pill’s protective effect lasted for a long time, too—up to 20 years after people stopped taking it.
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How effective is the pill at preventing pregnancy?
How effective the pill is at preventing pregnancy depends on what type of pill you are using and how consistently you take it. When used perfectly, the pill is more than 99% effective. But most of us aren’t perfect, so the pill’s effectiveness tends to be closer to 93%.
In other words:
For people who use the combination pill exactly as directed for a whole year, fewer than 1 in 100 will get pregnant when they don’t want to during the first year of using the pill. If you are using the progestin-only, mini-pill, it’s slightly less effective—98% with perfect use.
For people who do not use their pill exactly as directed (either kind), about 7 in 100 will get pregnant when they don’t want to during the first year of using the pill.
Does birth control work the minute I get it?
It depends on the method. Some forms of birth control including the pill, patch, ring, shot, and implant are not effective immediately after you start using them, but most IUDs are (and so are methods that you only use when you have sex, like a condom). To be sure, check with a health care provider before having sex without another method of birth control.
Can having diarrhea make the pill less effective?
Having “loose” poop every now and then probably won’t affect how well your pill works, but severe diarrhea (e.g. if you have it several times for more than 48 hours) might because the hormones in the pill are absorbed through your intestines over time. So, if you rely on the pill for pregnancy prevention and you have severe diarrhea that lasts more than 48 hours, it’s a good idea to use a backup method like condoms if you have sex while you’re sick and for the 7 days after you recover.
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Do antibiotics affect how effective the pill is?
In general, no. The only type of antibiotic that’s been shown to lessen the effectiveness of the birth control pill are rifamycins—including rifampin, rifapentine, rifalazil and rifaximin. Rifampin can be used to treat tuberculosis but is no longer the first choice for treatment and is not typically prescribed in the US.
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I threw up right after taking my pill. Now what?
If you throw up within two hours of taking your pill, treat it as a missed pill and take the next pill in your pack right away. Depending on which type of pill you use and where you are in your pill pack, you may need to use a back-up method like condoms for the next seven days to prevent pregnancy.
Can birth control help with endometriosis?
If you have endometriosis (a condition where tissue grows outside of your uterus instead of inside it), hormonal birth control can do wonders to lessen your symptoms. There are a bunch of hormonal methods that can help regulate your periods, decrease bleeding, or even make your period go away completely.

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