Health Matters Fact Sheets – Hormonal IUD

(Updated April 2013; also available in Spanish)

What are hormonal IUDs?

Hormonal intrauterine devices (IUDs) are a type of intrauterine contraception. With this form of birth control, a tiny device is placed in the uterus (womb) to prevent pregnancy. IUDs are made of soft, but strong, plastic, and they are in the shape of a “T”. A health care provider with training can insert an IUD quickly and easily.

Two brands of hormonal IUDs are available in the United States: Mirena® and Skyla.  They both contain a hormone called progestin. The same hormone is also in many birth control pills.

How effective is a hormonal IUD?

A hormonal IUD is very effective. Less than 1 out of 100 women who have an IUD will get pregnant. Hormonal IUDs are as effective as having your tubes tied. Your ability to get pregnant returns quickly after the IUD is removed.

Hormonal IUDs last a long time. Mirena works for at least 5 years, and Skyla works for at least 3 years.

How does a hormonal IUD work?

It blocks sperm from joining with an egg to prevent pregnancy. It does that in several ways:

  • The hormone in the IUD keeps ovaries from releasing eggs.
  • An IUD thickens mucus in the cervix. That keeps sperm from reaching the uterus and traveling to an ovary to meet an egg.
  • An IUD also affects the ability of the sperm to move toward the egg.

After a hormonal IUD is inserted, it takes about 7 days for it to start working. Be sure to use backup birth control (like a condom) for the first 7 days.

What are the benefits of a hormonal IUD?

  • It’s safe, convenient, and very effective.
  • It makes your periods lighter. Some women stop getting periods while they’re using a hormonal IUD.
  • You won’t have to think about birth control every day or every time you have sex.
  • Because one IUD can be used for so long, it’s one of the least expensive methods of birth control.
  • If you decide you want to get pregnant, you can have the IUD taken out. It’s a quick and painless process. For most women, fertility is back to normal a few weeks after the IUD is removed.

What are the disadvantages of a hormonal IUD??

  • A health care provider has to insert and remove it.
  • It doesn’t protect against sexually transmitted infections (STIs).
  • It can slip out of place. This is rare and is more likely to happen in women who haven’t had a baby.
  • It can increase cramps with your period. This is most common for the first 3 to 6 months. It also can cause irregular periods or spotting, but this is usually temporary.

Where can I get a hormonal IUD?

A trained health care provider can insert the IUD in a medical office or clinic.

Where can I get more information?

For more information on the hormonal IUD, talk to your health care provider.

Compare the hormonal IUD to other birth control options using ARHP’s Method Match