Hormonal IUDs are small plastic devices that release low levels of levonorgestrel, which is a synthetic version of the natural hormone progesterone.
This article is part of our Contraception Series!
What we're covering
Note: the information below was sourced from references (1-5), unless stated otherwise.
What is it?
Hormonal intrauterine (intra = inside, uterine = of the uterus) devices (IUDs) are small plastic devices that release low levels of levonorgestrel, which is a synthetic version of the natural hormone progesterone (explained below). An IUD is placed inside the uterus. It’s inserted through the cervix. Placement of an IUD can be very quick (about five minutes), but sometimes it takes longer, or it takes multiple tries. The IUD has to be replaced every three to seven years, depending on the brand.
Insertion of an IUD requires a pelvic examination, in which your doctor will want to look inside your vagina and inspect your cervix and uterus, sometimes also using ultrasound. They will typically first use their fingers, followed by insertion of a speculum. This can be uncomfortable, both physically and mentally. Let your doctor know if you’re nervous for the examination and procedure or if you’re uncomfortable at any time.
Insertion and removal of an IUD can be very painful. You could try over-the-counter painkillers before you go in for your appointment, but evidence suggests they aren’t very effective for the pain caused by IUD insertion or removal. Most doctors can give you local anesthesia before starting the procedure, which is more likely to help. Check with your doctor what options are available for you.
How does it work?
Levonorgestrel is a synthetic version of the natural hormone progesterone. It thickens the mucus in the cervix, which prevents sperm from coming up through the cervix into the uterus and fallopian tubes and fertilizing any eggs present there. The hormone also makes the endometrium (much) thinner, which often (depending on the type and brand of hormonal IUD) leads to a reduction in bleeding and pain during menstruation. This is also why IUDs may be recommended to people with endometriosis, because it can help with symptoms.
An IUD has two strings attached to the bottom, which are used by your doctor to take out the IUD and they’re helpful to see if your IUD is still in place. Your doctor might instruct you to regularly feel for the strings hanging from your cervix. This is because people sometimes spontaneously expel their IUD, meaning it’s coming out of your uterus and into your cervix (or out of your body all the way). This happens most often in the first month after placement of the IUD. Recent evidence also suggests that expulsion of an IUD is more common if you use a menstrual cup (6). You may or may not feel this happening, but if you think you lost your IUD, contact your doctor and use other contraception until the presence of your IUD is confirmed.
The strings can also sometimes be uncomfortable for a sex partner, because they might feel them with their penis. This usually doesn’t hurt, but if it does, you can ask your doctor to trim the strings. This can help.
Don’t worry about displacing or moving around an IUD during sex or exercise – this is highly unlikely to happen. A penis, sex toy, or fingers can’t go into the cervix, so they can’t reach the IUD in the womb. Even during penetration with fingers it’s incredibly unlikely to accidentally pull out an IUD. That said, it is possible that your IUD was already being expelled and you only noticed during sex. If you’re having bad cramping or bleeding, or you can feel something hard sticking out of your cervix, contact your doctor.
How effective is it?
Hormonal IUDs are very effective. Both perfect use and typical use protection rates are nearly 100%. Only 2 to 8 pregnancies occur each year per 1000 people* using the hormonal IUD. That’s a 0.2% to 0.8% chance of pregnancy.
What are possible side-effects?
Side-effects include acne, headaches, tenderness of your breasts, nausea, weight gain, mood changes, and changes in your bleeding pattern (mostly irregular spotting within the first six months of placement, and very light or lack of menstrual bleeding after six months). Very rarely, your IUD pokes a hole in the wall of your uterus (perforation). Lastly, some people develop cysts on their ovaries.
Some people develop an infection after placement, but this will typically only happen if you had an unrecognized infection of your cervix (for example, due to an STD) at the time of placement. This is why, if you have a higher risk of STD (for example, if you have sexual contact with lots of different people or if you’re a sex worker), your doctor may want to do an STD test before they place your IUD. Your doctor might ask you a few questions about your sexual habits to assess the need for testing.
Lastly, an IUD can increase your risk of an ectopic pregnancy if you do end up becoming pregnant. To learn more about ectopic pregnancy, read this article.
Hormonal IUDs can reduce your risk of cervical and endometrial cancer, and they can reduce the symptoms of menstruation (including reducing cramping and bleeding).
Note that only a portion of people experience (some of) these side-effects, and some people will experience side-effects not listed here. Whether you will, depends on many different factors.
When can't I use it?
When you’re experiencing pregnancy, pelvic infection (including pelvic inflammatory disease or PID), cancer of the uterus or cervix, certain rheumatic diseases, liver disease or a liver tumor, bleeding from your genitals due to unknown cause, or when your uterus is structured in such a way that an IUD won’t fit (or that it won’t be safe). You also can’t use the hormonal IUD if you have breast cancer or have had breast cancer.
Sometimes, you can get an IUD even if you have one of these things. Talk to your doctor to find out if your health issue would definitely mean you can’t get a hormonal IUD. Sometimes, you’re still able to get a copper IUD instead.
Does it work immediately?
This depends on your situation. If your hormonal IUD is placed within seven days after starting your menstruation, it is effective immediately. If you got your IUD after more than seven days since starting your menstruation, you need to use another method of contraception (for example, a condom) if you’re having sex in the seven days following your IUD insertion. You also need to do this if you’re more than three weeks postpartum and aren’t breastfeeding. Check with your doctor which situation applies to you if you’re not sure.
What happens to my fertility if I stop using it?
Fertility typically returns in about a month following removal of your IUD (7).
Does it protect against sexually transmitted diseases (STDs)?
No. Hormones alone do not protect against STDs. If you’re having sex with someone new or untested, use a barrier method as well.
*People, here, means anyone who is able to become pregnant, including girls, women, and non-binary people and transgender men who still have their uterus, vagina, and ovaries.
Are you curious about other methods to protect yourself from an unwanted pregnancy? Read about other birth control options here!
This article is pending medical review.
Written by Juliëtte Gossens
Reviewed by Sophie Oppelt and Selina Voßen
Edited by Juliëtte Gossens
McFarlane I (ed.). Seeing the unseen: The case for action in the neglected crisis of unintended pregnancy. United Nations Population Fund. 2022. Available from: https://www.unfpa.org/sites/default/files/pub-pdf/EN_SWP22%20report_0.pdf
Hacker NF, Gambone JC, Hobel CJ (eds.). Hacker & Moore’s Essentials of Obstetrics & Gynecology. 6th ed. Philadelphia: Elsevier; 2016.
Hoffman BL, Schorge JO, Halvorson LM, Hamid CA, Corton MM, Schaffer JI (eds.). William’s Gynecology. 4th ed. New York: McGraw-Hill Education; 2020.
Centers for Disease Control and Prevention. The United States Medical Eligibility Criteria for Contraceptive Use, 2016 (US MEC). Available from: https://www.cdc.gov/reproductivehealth/contraception/mmwr/mec/summary.html
Centers for Disease Control and Prevention. 2016 U.S. Selected Practice Recommendations for Contraceptive Use (U.S. SPR). Available from: https://www.cdc.gov/reproductivehealth/contraception/mmwr/spr/summary.html
Long J, Schreiber C, Creinin M, Kaneshiro B, Nanda K, Blithe D. Menstrual Cup Use and Intrauterine Device Expulsion in a Copper Intrauterine Device Contraceptive Efficacy Trial [OP01-1B]. Obstetrics & Gynecology. 2020;135(5 [Supplement]):15. DOI: 10.1097/01.AOG.0000662872.89062.83
Girum T, Wasie A. Return of fertility after discontinuation of contraception: a systematic review and meta-analysis. Contraception and Reproductive Medicine. 2018;3:9. DOI: 10.1186/s40834-018-0064-y
Please note: the information we provide to you here is for educational purposes only. If you’re experiencing any discomfort or have any complaints or questions about your health, please contact your doctor or other relevant health professional. We don’t provide medical advice.