The Ultimate Guide to IUDs - Allbodies

The Ultimate Guide to IUDs

The Ultimate Guide to IUDs

Thinking about an IUD? You’ve come to the right place. This guide will provide the lowdown on everything you’ve ever wanted to know IUDs - the good, the bad, and the bloody.


The IUD, or intrauterine device, is a form of birth control belonging to a class of contraceptive methods known as LARCs, or Long-Acting Reversible Contraceptives. In the U.S, all IUDs are T-shaped (and much smaller than you’d think!), though in the UK and other places around the globe, they are available in different shapes and sizes! T-shaped IUDs sit in the uterus to prevent pregnancy.  

There are two types of IUDs- hormonal and nonhormonal. Both types are made of a body-safe plastic. The nonhormonal also has a thin copper wire coating. IUDs are super effective at preventing pregnancy, over 99%! (1), and you get to avoid the hassle of remembering to take a daily pill/apply a patch/etc.

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In the U.S. hormonal IUDs go by the following brand names: Mirena, Liletta, Skyla, and Kyleena.  (Apparently, IUDs are Disney Princesses)

How Do They Work?

Hormonal IUDs all function in a similar way, by releasing a low-and-slow dose of Progestin into the endometrium AKA the lining of the uterus. Progestin is the synthetic version of progesterone, which is a hormone your body makes naturally. Progestin does a few things to prevent pregnancy (2):

  • Lowers the likelihood of monthly ovulation. Low chance of ovulation means low chance of fertilization and subsequently, low chance of pregnancy.
  • Thins endometrial tissue (uterine lining), so on the off chance that an egg did get fertilized, it’s unlikely it would be able to implant there.
  • Thickens cervical mucus, creating a barrier for all but the most ambitious sperm to get through.
How Effective Is It?

While getting pregnant on the hormonal IUD is possible, these three factors work in conjunction for extremely effective pregnancy prevention (99.7%). This means that out of 100 people, one (and maybe not even one) may get pregnant with a hormonal IUD in place. (2) 

V. IMPORTANT NOTE ALERT! It can take about a week after IUD insertion to become fully effective. So using a backup method, like condoms, is essential if you choose to have sex within seven days of getting one.
Hormonal IUD Options

Some main points to consider when deciding between hormonal IUDs are: 1) How much hormone is in it,  2) how long it’s effective, and, 3) your personal history. We made you a helpful chart!


Hormonal IUDs retail for anywhere from $75-1300, so it’s a big range. Luckily, almost all public insurance programs will cover 100% of the cost, meaning you pay $0. Private insurers have their own rules, so check with your insurance to know how much you may have to pay out of pocket.

Effects on Menstruation

You will still bleed while on hormonal IUDs, though generally speaking, it tends to be shorter and lighter than a typical period. You may also have some spotting outside of a monthly bleed, especially in the first 3-6 months (pantyliners, people!)

At around the one-year mark, 20% of Mirena users have no bleeding at all. (3) Mirena is also FDA-approved to treat dysmenorrhea – heavy, painful, crampy periods. Although not FDA approved to do so, Liletta will also likely help with those things as well (4). Bleeding and spotting are more likely to continue on Skyla and Kyleena – so if it’s important to you to keep having a cycle, those may be a more attractive option.  

Effects on Sex

For some people, having a hormonal IUD can be helpful for libido because they feel more relaxed knowing they are protected from pregnancy.

For others, it can decrease libido (5). Some find that their libido returns once their body gets adjusted to the hormonal IUD. If your sex drive feels impacted in an undesirable way, talk to your provider about other options! And check out some tips for increasing libido here.

Some couples also report being able to feel the IUD strings during sex. Over time, the strings tend to soften and curl up around the cervix, becoming less noticeable, but, if they are bothering you, you can always request that your doctor give ‘em a little trim.

Effects on Fertility

Because IUDs deposit hormones locally into the uterus (as opposed to systemically, e.g into the bloodstream), return to fertility is quicker than with other methods. If you have your IUD removed, you could theoretically ovulate and become pregnant the next day – although it may not happen that quickly (4). Most people will become fertile again in 2-3 months (2), but that doesn’t mean it’s easy for everyone to get pregnant that quickly. Remember, the consistency of your cervical fluid changed from the IUD and fertile fluid is necessary to help those sperm swim, so if pregnancy is your goal, be patient with yourself and give your bod some time to adjust.

If you remove your IUD and don’t want to become pregnant, make sure you’re using something else for birth control.

And, see below on Pelvic Inflammatory Disease (PID).

Side Effects to Look Out For

Hormonal IUDs interact with your unique body chemistry and genetics, which means that side effects may vary a lot between individuals. Not everyone will experience side effects, and those who do may experience them differently. It’s tough to predict which, if any, side effects you may experience, so it is important to check in and see how you feel along the way. Side effects do tend to lessen the longer your IUD is in, but that doesn’t mean you need to suffer if something feels off to you. Trust your gut.

Some of the most common side effects are:

  • Changes to your period, like irregular bleeding and spotting
  • Mood changes
  • Hormonal acne, especially along the jawline.
  • Breast/chest tenderness
  • Headaches

The following complications from the hormonal IUD are much rarer, but also much more serious, and can even be life-threatening in extreme cases. If you experience any of the complications listed below, get to your local ER ASAP:

  • Severe, sudden headache
  • Severe abdominal pain or leg pain
  • Fever
  • Vision changes


“There is some evidence to suggest that having a pre-existing condition like depression may increase your risk of worsening the condition when it comes to hormonal IUDs. Therefore the recommendation is that it is not the first line of contraception (that would be the copper IUD instead). This finding isn’t absolute though, so if a hormonal IUD still feels like the best fit for you, you can definitely still use it!”


In the U.S, Paragard, is the only nonhormonal, or “copper IUD” option available. As the name suggests, it contains no hormones, and lasts for up to 12 years – longer than any other reversible birth control method. It’s a good option for someone who wants a hormone-free method that is still highly effective at preventing pregnancy (99.2%). Costs vary between $800-$1100 retail, but most insurance plans cover 100% of the cost (thanks, ACA!).

How Does It Work?

The non-hormonal IUD, Paragard, works a bit differently. It’s efficacy is based on the presence of copper, which wraps around the IUD in a coil and is toxic to sperm. The copper also causes a moderate inflammatory response in the endometrium, which makes it a very unfriendly environment for a pregnancy to thrive. (8)

Effects on Fertility?

There are no long-term effects on fertility with Paragard. Because it’s essentially just a little piece of copper in your uterus, once it’s in, it’s working, and once it’s out, pregnancy becomes possible right away. This being said, for those trying to get pregnant, a copper-less uterus is still something your body will need to adjust to, so pregnancy certainly may not happen right away.  Be patient with yourself and let your body do its thing while you adjust to post-Paragard life.

And, see below on Pelvic Inflammatory Disease (PID).

Effects on Sex?

Because it’s non-hormonal, Paragard shouldn’t affect your sex drive. Bonus: It takes effect instantly, so once it’s placed, you’re protected from pregnancy.

Effects on Menstruation?

Paragard users will still ovulate and have a regular cycle. However, periods may become heavier, longer, and crampy-er with Paragard. This is because the copper in Paragard creates an inflammatory response in the lining of the uterus, as well as a decrease in the amount of prostaglandins your uterus metabolizes. Prostaglandins increase cramping, and with the copper IUD you don’t process them as efficiently- which may lead to increased cramping (9). In short, it makes your uterus very cranky. The good news is that for most people, this effect lessens the longer Paragard is in place.

How Effective Is it?

The copper IUD is 99.2% effective at preventing pregnancy, which, considering it’s essentially a chunk of copper in your uterus, is pretty darn impressive (8). Unlike hormonal IUDs, the copper IUD takes effect instantly to prevent pregnancy. This also makes it a very effective option for emergency contraception (99% effective when inserted up to 5 days after unprotected sex). Read our article on Emergency Contraception (LINK) for more info on this.

Side Effects To Look Out For?

Like with any medical device, the copper IUD carries small risks. Things like infection or perforation are unlikely, but possible. The copper IUD also carries a slightly higher risk of bacterial vaginosis (BV) infection – probably due to the fact that you have a heavier, longer cycle with the copper IUD and that may put your vaginal microflora out of balance (10).

If you develop any dizziness, lightheadedness or extreme exhaustion, let your doctor know right away. Same goes for if you develop a fever, have severe abdominal or pelvic pain, or pain during sex.

V. IMPORTANT NOTE ALERT! CHECK YOUR STRINGS! While IUDs are super low maintenance, it’s good practice to check your IUD strings once a month (with clean fingers) to ensure that it is still in place. Generally, IUDs stay put once they are placed. Rarely an IUD will expel, meaning the uterus contracts hard enough to partially or completely push it out through the cervix. If you are ever unable to feel your IUD strings with your fingers, or you feel hard plastic where your soft strings should be, call your doctor right away and let them know. If you are under 25 years old, your risk of expulsion is higher, so remember to check!


  • Am I okay with a heavier and longer period, with potentially more cramping?
  • Am I currently anemic or prone to anemia?
  • Am I at risk for my body being sensitive to copper?
  • Can I tolerate a pelvic exam and some discomfort with insertion? It’s quick, but may involve some intense cramping.
  • How do I feel about introducing hormones into my body?
  • Do I have or have I ever had liver disease?
  • Am I OK with inconsistent and unpredictable bleeding?
  • Am I OK with not bleeding at all?
  • Am I already prone to yeast infections or BV?
  • Am I at risk for STIs? Have I been tested for STIs recently?


Unlike the birth control pill, patch, and ring that contain estrogen, the hormonal IUD only contains Progestin (2). Estrogen may raise health risks for people who are smokers over 35, get migraines with aura, have a history of stroke, DVT (blood clot), or breast cancer. Because of this, IUDs are often a safer choice for people who have these health issues. It’s also nice that you don’t have to remember to do all that much with your IUD- no prescription refills, daily alarms, etc.


Pelvic Inflammatory Disease (PID) is an infection in the reproductive organs that can affect your fertility. There are multiple ways you can PID and if you search the interwebs you will see mixed results on whether an IUD can cause it. Bedsider claims that IUDs do not cause PID.  Literature reviews like this one say they aren’t sure, but also the funding from this review came from a board member of Bayer who makes IUDs (womp womp). The CDC does list the IUD as a possible cause, stating the small increased risk is mostly limited to the first three weeks after the IUD is placed (11). While the risk is very small- 1% in the first month, 0.1% after that (12)- PID is serious. So if you experience any of the following symptoms with an IUD in place, check in with your provider just in case (11):

  • Pain in your lower abdomen;
  • Fever;
  • An unusual discharge with a bad odor from your vagina;
  • Pain and/or bleeding when you have sex;
  • Burning sensation when you urinate


We’re not gonna lie… it can be unpleasant! However, the level of discomfort you may actually experience varies based on several factors, including where you are in your cycle*, the size and depth of your cervix and uterus, any pre-medication you receive, whether you’ve given birth before, and your personal pain tolerance. Most people who get an IUD liken the process to several strong, sharp cramps, not unlike intense period cramps. The experience of getting an IUD can also be triggering for some, especially survivors of sexual trauma. It’s okay to let your provider know ahead of time, and bring a support person along.

The process from end-to-end goes a little like this:

  1. You arrive and get checked in. The medical assistant or nurse will take your temperature, blood pressure, and ask you some general health questions.
  2. You will get a urine pregnancy test, usually. This is just to make sure you’re not pregnant at the time of IUD insertion.
  3. You get undressed from the waist down and lie back on the exam table. Your healthcare provider will insert a speculum into your vagina and prep your cervix with a betadine swab. This may feel like some pressure and a weird kind of tickle, but it should not be painful. They may also do a quick chlamydia/gonorrhea test at this point, unless they took a urine test already. This will be in the form of another vaginal swab.
  4. After prepping and cleaning your cervix, your doctor will stabilize it using a clipping instrument. This holds your cervix steady while they insert the IUD. This may feel like a small pinch.
  5. Once stabilized, your healthcare provider will measure your uterus using a sounding device. Kind of like using a dipstick to check the oil in your car, the sound tells the doctor the depth of your uterus so they know how far back to place the IUD. This generally feels like a strong cramp that lasts a few seconds.
  6. After sounding, you are ready for the IUD. Your provider will take the IUD, which comes in a tube that looks like a thin straw, and gently push the tube into your cervix. Once the tube is far enough back in your uterus, they will release the IUD and it will “pop” out of the tube and into place. They will hold it there for a few seconds, allowing the IUD arms to fully expand, then remove the tube leaving the IUD in place. They will then trim the strings to a couple centimeters, remove the speculum, and you’re done! You may feel another strong cramp or two during this last part. Some people also experience some temporary nausea or dizziness due to their vaso-vagal nerve being stimulated.
  7. After insertion, your provider will generally give you a couple minutes alone to recover. Take your time and make sure you feel steady before getting up.
V. IMPORTANT NOTE ALERT! Try to schedule your IUD insertion during your period, as your cervix will be already be slightly dilated then and insertion might be less painful. Don’t worry about the blood- we guarantee your healthcare provider is used to it.


Removal is generally quicker and less painful than insertion. Your healthcare provider will have you lie back on the exam table and place the speculum in your vagina. Using a ring forceps, they will grasp the IUD strings and gently tug to remove it. A little bit of cramping is common, but it shouldn’t be as intense as insertion.

Written by: Caitlin O’Connor, Birth control/family planning counselor at UCLA OBGYN

All content found on this Website, including: text, images, audio, or other formats, was created for informational purposes only. The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. 

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Contributions and Research by: Caitlin O’Connor