The Birth Control Pill vs. the IUD: Which is More Effective?

    Thinking of starting birth control, or switching from your existing form of birth control to another option? The pill and the IUD are both highly effective ways of stopping yourself from becoming pregnant, each with their own unique advantages and disadvantages.

    The birth control pill uses either a combination of hormones or a single hormone to prevent you from becoming pregnant. The IUD, on the other hand, uses either hormones or copper to block sperm from entering into your uterus and causing pregnancy.

    We’ve explained how each form of birth control works in more detail below, as well as the major advantages and disadvantages of each form of birth control. We’ve also listed the common side effects you might experience from using the pill or the IUD.

    The Birth Control Pill

    The pill is a form of hormonal contraception, meaning it uses specific hormones to prevent you from becoming pregnant.

    There are two different types of birth control pill available. The first, the combination pill, uses a combination of ethinyl estradiol (a synthetic form of estrogen) and a progestin hormone to stop you from becoming pregnant.

    The combination pill prevents you from becoming pregnant by stopping you from ovulating, as well as by thickening the cervical mucus inside your vagina. This makes it harder for sperm to physically travel into your uterus, reducing the risk of sperm fertilizing an egg.

    The second, the progestin-only pill, doesn’t always cause you to stop ovulating. Instead, it works by thickening your cervical mucus and blocking your partner’s sperm from making their way into your uterus. 

    Although the combined and progestin-only pill have similar benefits, they also have several key differences. We’ve covered these differences in our guide to combined and progestin-only birth control. 

    There’s no “best” type of birth control pill for everyone. Your doctor will choose the most suitable pill for you based on factors like your medical history, age, use of other medications and risk of experiencing side effects. 

    Whichever type of pill you choose, you’ll be very well protected from the risk of pregnancy if you use the pill correctly. Used perfectly, both the combined and the progestin-only birth control pill are 99 percent effective at stopping you from becoming pregnant.

    In “real life” circumstances, with the occasional late or forgotten pill, both types of birth control pill are 91percent to 92 percent effective at preventing pregnancy. This makes it important to take your pill exactly as instructed to make sure you’re as protected as possible.

    Advantages of the Pill

    The pill is a common and convenient form of birth control. If you take it daily at the same time every morning, you may be up to 99 percent protected against the risk of becoming pregnant from sex, all without having to worry about using other forms of contraception.

    Not all birth control pills use the same cycle length. Certain pills have a cycle that lasts for 28 days, whereas other birth control pills use an extended cycle that can last for as long as three months at a time. 

    This means that you’ll be able to skip two out of every three periods if you choose an extended cycle birth control pill. 

    Since the pill comes with a cycle calendar, keeping track of your cycle is simple. If you make a point of taking your pill every day, it’s usually easy to comply with the instructions provided with your birth control pills and keep yourself fully protected.

    As well as keeping you protected from pregnancy and allowing you to skip your period, the pill has a variety of additional benefits. 

    If you get period pain, cramps or discomfort, you might notice your period becoming lighter and easier to tolerate after you start using the pill. Your period might also become shorter, letting you get back to your normal life in less time every month.

    Our guide to how birth control affects your period covers this topic in more detail, with real data on how the pill can make your period easier to deal with. 

    If you take a combined birth control pill such as Yaz, Estrostep or Ortho Tri-Cyclen, you might also notice your acne disappearing. These three pills can suppress the hormones that cause acne and are approved by the FDA as hormonal acne treatments. 

    Our guide to birth control pills and acne covers this topic in more detail, with links to studies on how combined birth control pills can be used for treating and preventing acne. 

    The pill can also reduce your risk of developing ovarian cysts, endometrial and ovarian cancers and some vaginal infections. If you use the birth control during your 20s and 30s, it also might reduce your risk of developing osteoporosis when you’re older.

    Disadvantages of the Pill

    Like all forms of hormonal birth control, the pill has several disadvantages, from side effects to the possibility of becoming less effective if you don’t use it correctly.

    First, the birth control pill does have side effects. Most of these side effects are relatively minor, ranging from fluid retention to breast tenderness, nausea and spotting. It’s common for the side effects of birth control to occur during the first few months of use before gradually stopping. 

    You can learn more about the side effects of the birth control pill, as well as how likely they are to affect you, in our guide to birth control side effects

    The pill also has several less common, more serious potential side effects. The biggest of these is a slight increase in your risk of blood clots. If you’re older than 35 and smoke, taking the birth control pill could significantly increase your risk of experiencing these side effects.

    You can learn more about these side effects, as well as the most significant risk factors, in our guide to smoking and birth control

    Second, the pill has the potential to affect your sex drive. Although rare, it’s possible for you to experience a decrease or an increase in your level of interest in sex after you start to take the birth control pill. 

    There are also practical disadvantages to the pill. In order for it to be as effective as possible at preventing pregnancy, you’ll need to take it at roughly the same time daily. This can be difficult or impractical if your job requires you to work on a shift-based schedule.

    While the pill will protect you from pregnancy if you use it properly, it won’t protect you from the risk of catching an STD. This means you’ll need to use condoms or a different barrier method of birth control if you’re not sure about your partner’s STD status. 

    The IUD

    The IUD is a small device that’s fitted inside your uterus. It prevents pregnancy by stopping your partner’s sperm from coming into contact with an egg. IUDs can be copper or hormonal, both of which work effectively to prevent pregnancy.

    Copper IUDs work by repelling sperm using copper. Copper is a highly toxic element for sperm, meaning the copper IUD can repel sperm and stop them from entering your uterus and coming into contact with an egg. 

    Hormonal IUDs work by releasing a small dose of progestin hormones into your uterus. These hormones thicken your cervical mucus, physically blocking sperm from coming into contact with an egg. 

    Like the progestin-only birth control pill, the hormonal IUD can also prevent you from ovulating, although this isn’t a consistent effect. 

    The IUD is fitted inside your uterus by a doctor or nurse in a process that usually takes less than five minutes. Normally, your doctor or nurse will offer you medication before they insert the IUD to make sure you’re comfortable. 

    Depending on the type of IUD you have fitted, you’ll normally be protected from pregnancy for three to seven years. Some IUDs, such as the ParaGard IUD, can protect you from becoming pregnant for up to 12 years at a time before they need to be replaced.

    Like the pill, the IUD is very effective at preventing pregnancy. On average, both the copper and hormonal IUD are 99 percent effective at preventing you from becoming pregnant. Because you don’t need to take a pill every day, there isn’t a lower “real life” effectiveness rate with the IUD.

    Advantages of the IUD

    The biggest advantage of the IUD is its convenience. Once it’s fitted, the IUD will last for three to 12 years as a form of birth control. During this time, there’s no need for you to worry about daily pills, weekly patches or other forms of contraception.

    Because the IUD works continuously after it’s fitted inside your uterus, there’s no risk of missing a dose or other common issues that can make the pill less effective. It’s also impossible to use the IUD incorrectly, which is a common problem with barrier methods such as condoms. 

    Because the IUD is available with either copper or hormones, it offers a few unique advantages over other forms of birth control.

    If you’re sensitive to estrogen and/or progestin hormones, the copper IUD allows you to protect yourself from pregnancy without any exposure to exogenous hormones. This makes it a useful form of birth control if you experience side effects from the pill, the patch or the ring. 

    If you experience pain and discomfort before and during your period, the hormonal IUD can help to make your period lighter and easier to tolerate. Many women experience fewer cramps and a lighter, shorter period after they start using the hormonal IUD. 

    Like the pill, the IUD doesn’t stop you from becoming pregnant in the future. If you decide that you’d like to become pregnant, you can contact your doctor and schedule an appointment for your IUD to be removed. 

    Unlike the Depo-Provera birth control injection, the IUD stops working as soon as it’s removed, meaning you’ll usually be able to become pregnant as soon as it’s taken out of your uterus.

    Finally, some IUDs can be used as a form of emergency contraception. When you have some types of the copper IUD installed, you’ll be 99 percent protected against pregnancy from sex you’ve had in the previous five days. 

    Disadvantages of the IUD

    Like other forms of birth control, the IUD birth control side effects exist. In the first few months after the IUD is fitted, you might experience heavier periods, spotting (bleeding that occurs between your periods) and more severe cramping during your period. 

    It’s also quite common to experience some discomfort, cramps and back pain in the week after the IUD is fitted.

    There are also a few more serious IUD birth control side effects. After it’s fitted, the IUD can slip out of place, increasing your risk of becoming pregnant. It’s also possible to develop an infection if bacteria enter your uterus while the doctor or nurse is fitting the IUD.

    Most seriously, the IUD could increase your risk of ectopic pregnancy if you become pregnant while it’s installed. 

    These side effects are rare and unlikely to affect you. However, if you can feel your IUD coming out from your cervix, or have painful side effects from the IUD, it’s best to contact your doctor for assistance as soon as possible. 

    Finally, since the IUD doesn’t create any physical barrier between you and your partner, it won’t protect you from STDs. Just like with the birth control pill, you’ll need to use condoms or take an STD test with your partner to have safe sex. 

    Birth Control or IUD: Which is More Effective?

    Used perfectly, the birth control pill and the IUD are both 99 percent effective at preventing you from becoming pregnant. 

    However, since it’s possible to forget your pill or take a dose late, in real life conditions, the IUD is slightly more effective as a form of birth control. 

    There’s no “best” form of birth control for everyone. If you don’t like the idea of having an IUD fitted, have concerns about the side effects or simply prefer taking a pill to using the IUD, you might prefer using the pill.

    On the other hand, if you don’t like the idea of taking the pill every day or have concerns about the possibility of missing a dose, you might prefer using the IUD.



    This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.