An intrauterine device (IUD) is a small, T-shaped piece of plastic that’s placed inside the uterus to prevent pregnancy. As one of the most effective forms of long-acting reversible contraception (LARC), an IUD can protect against pregnancy for several years—without daily maintenance or effort.

There are two main types of IUDs: hormonal and copper. Both sit inside the uterus, but they prevent pregnancy in different ways.

The hormonal IUD, available under brand names like Mirena, Liletta, Kyleena, and Skyla, releases progestin, a synthetic version of the hormone progesterone. This thickens cervical mucus, making it harder for sperm to reach the egg.

The copper IUD (Paragard) contains no hormones. Instead, it releases small amounts of copper into the uterus, creating an environment that is toxic to sperm and prevents both fertilization and implantation.

If you’re planning to get an IUD or simply want to know what the process involves, here’s a detailed look at how the insertion works, what pain or side effects you might experience, and what to expect afterward.

How An IUD Is Inserted

IUD insertion is a brief procedure performed by a healthcare professional—usually an OB-GYN or nurse practitioner—at a clinic or doctor’s office. The process typically takes less than 10 minutes.

timing the insertion
Your provider may recommend inserting the IUD during your period. During menstruation, the cervix naturally opens slightly, making insertion easier and minimizing the chance of being pregnant.

preparation before the procedure
Before placing the device, your healthcare provider may:

  • Perform a pelvic exam to check your uterus and cervix.

  • Order a pregnancy test to confirm you’re not pregnant.

  • Test for sexually transmitted infections (STIs) to ensure there’s no existing infection before insertion.

You should not have an IUD inserted if you are pregnant, might be pregnant, or currently have a pelvic or vaginal infection.

Step-By-Step IUD Insertion Procedure

1. Cleaning the cervix
Your healthcare provider will use an antiseptic solution to clean your cervix and vagina to minimize infection risk.

2. Inserting the IUD
A thin, flexible plastic tube called an inserter is gently passed through your cervix into your uterus. The IUD, folded inside the tube, is then guided into position.

3. Placement of the IUD
Once in place, the IUD’s arms open into the familiar “T” shape to fit snugly within your uterus. The provider will remove the inserter and make sure the device is correctly positioned.

4. Trimming the strings
The IUD comes with two thin plastic strings attached to its base. These strings extend through the cervix into the upper vagina. They allow you (and your healthcare provider) to check that the IUD remains in place and are also used for removal later.

Most people don’t feel these threads, and sexual partners typically can’t detect them. However, if you do find them uncomfortable, you can ask your provider to trim them shorter.

How Painful Is IUD Insertion?

Pain and discomfort during IUD insertion vary widely from person to person. Many people describe the sensation as cramping similar to menstrual pain, while others experience mild to moderate discomfort.

Common symptoms during or right after insertion include:

  • Cramping or lower abdominal pain

  • Dizziness or lightheadedness

  • Mild nausea

These sensations usually subside within a few minutes after the procedure.

managing discomfort
Taking an over-the-counter pain reliever such as ibuprofen (Advil) or acetaminophen (Tylenol) before your appointment can help reduce pain. Some providers may also use a local anesthetic, called a paracervical block, to numb the cervix. This involves injecting a small amount of numbing medication near the nerves that supply the cervix, reducing cramping and discomfort.

what studies show about pain levels
Research suggests that most people find the pain of IUD insertion less intense than expected. In one study, those who had never given birth vaginally rated their discomfort as moderate but manageable. Participants who had given birth before reported significantly less pain than they anticipated.

What To Expect After IUD Insertion

Following your IUD placement, you may experience mild side effects as your body adjusts. These are normal and temporary.

common short-term symptoms

  • Cramping or pelvic discomfort for 1–2 days

  • Light bleeding or spotting between periods

  • Feeling tired or lightheaded right after the procedure

You can use OTC pain medication for relief. Cramping usually eases after a few days, though some people may experience intermittent cramps for a few weeks.

period changes

  • Copper IUDs may cause heavier or longer periods, especially during the first few months.

  • Hormonal IUDs often lead to lighter periods, less cramping, or even amenorrhea (no periods) after several months.

Possible Side Effects And Risks

Most people use IUDs safely without major issues. However, some side effects and rare complications can occur.

mild side effects (first few months)

  • Spotting or irregular bleeding

  • Breast tenderness

  • Mood swings

  • Nausea or mild headaches

These effects usually resolve as your body adjusts to the IUD’s presence and, for hormonal types, its hormones.

rare but serious risks

  • Infection: Bacteria introduced during insertion can cause a pelvic infection.

  • Uterine perforation: The IUD may rarely puncture the uterine wall during insertion.

  • Ectopic pregnancy: If pregnancy occurs with an IUD in place, it’s more likely to be ectopic (outside the uterus).

  • Expulsion: In very rare cases, the IUD can slip out of position or fall out completely.

If you experience fever, severe cramps, foul-smelling discharge, or unusual bleeding, contact your healthcare provider immediately.

When Does An IUD Start Working?

Copper IUDs start preventing pregnancy immediately after insertion.

Hormonal IUDs take about seven days to become fully effective. During this initial week, it’s essential to use a backup form of contraception, such as condoms.

Once active, both types of IUDs offer more than 99% effectiveness in preventing pregnancy.

How Long Can You Keep An IUD?

IUDs provide long-term protection and can be removed at any time if you decide to become pregnant or switch methods.

duration by type:

  • Hormonal IUDs: Effective for 3–8 years, depending on the brand.

  • Copper IUDs: Effective for up to 10 years.

Your provider can safely remove the device whenever you wish—it’s a quick, simple procedure that restores fertility almost immediately.

When To Contact Your Healthcare Provider

You should schedule a follow-up visit about 2–4 weeks after insertion to ensure the IUD is properly positioned.

In addition, contact your provider if you notice:

  • Severe or persistent cramping

  • Heavy or unusual bleeding

  • Discharge with a bad odor

  • Pain during sex

  • The IUD strings feel longer, shorter, or are missing

  • You suspect you’re pregnant

These signs could indicate displacement, infection, or other complications that need medical attention.

A Quick Overview

An IUD is a small, flexible device placed inside the uterus to prevent pregnancy for years at a time. The hormonal IUD releases progestin to thicken cervical mucus and thin the uterine lining, while the copper IUD prevents fertilization by releasing copper ions that are toxic to sperm.

Insertion is a quick, in-office procedure performed by a healthcare provider. Mild pain, cramping, or light bleeding afterward is normal and temporary. Once settled, IUDs offer highly effective, reversible birth control—allowing you to plan your reproductive future with confidence and convenience.