Both are about equally effective when used properly — IUDs are long-lasting and don’t require you to think about them

Choosing to use birth control, and which kind you take, is probably one of the most personal of personal choices.

And the list of birth control options is long — from barrier methods like condoms, to patches, injections and more.

Intrauterine devices (IUDs) and birth control pills are among the most commonly used contraception options out there. But how do you choose? What are the differences between an IUD and the pill?

Ob/Gyn Salena Zanotti, MD, weighs in.

Differences between IUDs and the pill

The biggest difference between IUDs and birth control pills comes down to how often you have to think about them.

  • IUDsare medical devices that a women’s health specialist implants in your uterus to prevent pregnancy for several years.
  • Birth control pills are a medication you take daily to prevent pregnancy.

“IUDs are a ‘set-it-and-forget-it’ birth control option that provides pregnancy prevention for three to 10 years, depending on the device being used,” Dr. Zanotti explains. “Birth control pills are something you have more control and oversight with.”

How they work

How they work is different, depending on the exact type of pill or IUD you use. Let’s break that down:

  • Birth control pills keep your body from releasing an egg (ovulating). Some contain both estrogen and progesterone. Others use progesterone only.
  • Hormonal IUDs deliver a steady stream of progesterone to your uterus. You still ovulate with a hormonal IUD. They prevent pregnancy by keeping a fertilized egg from implanting.
  • The copper IUD (ParaGard®) doesn’t contain hormones at all. It prevents pregnancy by releasing copper, which keeps sperm from being able to reach an egg. It also keeps eggs from implanting.

Lifestyle and goals

When choosing between an IUD and the pill, one of the biggest considerations is how often you have to think about your birth control.

“Birth control pills are a daily commitment. That’s not ideal for everyone,” Dr. Zanotti acknowledges. “You need to be diligent about taking them at the same time every day and not skipping a pill.”

On the other hand, birth control pills provide you with some flexibility. If you decide you want to try to conceive, you simply stop taking them.

“If you have an IUD and you determine that pregnancy is a goal, you’ll need to visit a women’s health professional to have it removed,” she says. It’s not a good idea to remove an IUD at home. Leave it to the pros, please.

Effectiveness

Both IUDs and the pill are more than 99% effective at preventing pregnancy when used exactly as directed.

With the pill, that can be a tall order. Remember, birth control pills should be taken at the same time every single day. So, in reality, the effectiveness of the pill is closer to 95% when you account for human error.

“It’s not that the medication itself is any less effective. It’s that life happens, and sometimes, you just forget a pill,” Dr. Zanotti recognizes.

Along those lines, IUDs need to be removed and replaced on schedule.

“IUDs lose effectiveness after their expiration date,” she continues. “So, you want to make sure you know when that is and make your appointment in time so not to fall outside of that window.”

The other concern affecting IUDs is that they can, although rarely, become dislodged. That can keep them from working properly. Signs that your IUD is out of place include:

  • Abnormal discharge
  • Bleeding
  • Pain or cramping
  • No longer being able to feel or find the strings

Side effects and impact on your period

It’s tough to say exactly how your body will respond to either an IUD or birth control pills. And your experience may be different from your friends’.

IUDs and the pill can come with many of the same side effects, like:

  • Headaches
  • Breast tenderness
  • Moodiness
  • Spotting

And both may make your periods lighter.

“We often expect that IUDs and pills can lead to lighter periods or no periods at all,” Dr. Zanotti notes. “But not everyone will have that experience.”

Some studies estimate that after a year of having an IUD, there’s a 20% chance you could go 90 days or more without a period. Heavier periods are also possible when starting an IUD.

When you take a combination birth control pill — the kind that includes both estrogen and progesterone — you may be able to skip periods, if recommended by your provider. That’s done by not taking the fourth week of pills and moving straight to the next pack. It doesn’t always work, but it may be an option in some cases.

Fertility after stopping

Whether you choose birth an IUD or birth control pills, you can get pregnant immediately after you stop using them. That’s why taking pills consistently is so important if you don’t want to get pregnant.

“Missing a progesterone-only pill by even a few hours, for example, greatly increases your chances of getting pregnant,” Dr. Zanotti stresses.

Combination pills aren’t quite that sensitive. But consistency is still very important.

Similarly, you can get pregnant very soon after having an IUD removed. So, if you don’t plan to get pregnant, you should either have another one inserted or begin a new form of birth control before having sex.

“There really aren’t any lingering contraceptive effects once you stop taking pills or have an IUD removed,” she emphasizes. “The medications leave your system very quickly.”

Bottom line

All in all, choosing between an IUD or the birth control pill is typically a matter of preference.

“Both pills and IUDs are highly reliable as long as they’re used properly,” Dr. Zanotti says.

Talk with a healthcare provider about your goals and the different options.