Intrauterine devices are small T-shaped tools placed in the uterus by a trained clinician. Hormonal IUDs release progestin locally, often lightening periods. Copper IUDs provide hormone-free contraception for up to ten years.

Insertion may cause brief cramping; over-the-counter pain relief and rest help. Expulsion is uncommon but possible—check strings as instructed and report missing threads.

IUDs are safe for most nulliparous (never pregnant) individuals and adolescents. They can be removed anytime fertility is desired.

Partner sensation of strings usually diminishes over time. IUDs do not protect against STIs.

Hormonal versus copper

Both IUDs are among the most effective reversible contraceptives available. Hormonal IUDs release a small amount of progestin locally, often making periods lighter or absent and reducing cramps, and last several years depending on the type. The copper IUD is hormone-free, works by making the environment hostile to sperm, can last a decade or more, and doubles as emergency contraception—though it may make periods heavier, particularly at first.

Insertion, adjustment, and aftercare

Insertion is a brief in-office procedure that can cause cramping; discussing pain relief beforehand is reasonable. Irregular spotting for the first few months is common with both types as the body adjusts. Once settled, IUDs require little maintenance beyond an occasional check that the strings are in place.

When to seek care

Severe pain, fever, unusual discharge, or a suspicion that the device has moved should prompt evaluation. An IUD does not protect against STIs, so barrier methods remain important with new partners.

The Structural Difference Between Hormonal and Copper IUDs

Both types of intrauterine device are small T-shaped frames placed inside the uterine cavity by a trained clinician, but their mechanisms diverge completely. Hormonal IUDs — the Mirena, Kyleena, Liletta, and Skyla brands are the most widely available — release a synthetic progestogen (levonorgestrel) locally into the uterus. The primary effect is thickening cervical mucus to a degree that is virtually impermeable to sperm, alongside thinning of the endometrial lining. Ovulation is suppressed partially in about 50 % of users, particularly with higher-dose devices.

The copper IUD contains no hormones at all. Copper ions released by the device are toxic to sperm, impairing motility and viability so effectively that fertilisation rarely occurs. The copper IUD also creates a mild inflammatory response in the uterine environment that is inhospitable to both sperm and eggs. This makes it the most effective form of emergency contraception as well as a highly effective ongoing method — over 99 % effective in both cases.

Duration, Replacement, and Cost Considerations

Copper IUDs last 5–10 years depending on the specific device; some evidence supports extended use of certain models beyond the licensed duration. Hormonal IUDs vary: the Mirena is licensed for five years (and evidence supports up to eight years for contraceptive use); the Kyleena for five years; the Skyla for three years. All can be removed earlier if the user wishes to conceive or switch methods — fertility returns to its baseline within the first ovulatory cycle after removal.

The upfront cost of insertion is higher than monthly contraceptives, but when spread over the device's lifespan, IUDs are among the most cost-effective methods available. In many national healthcare systems, IUDs are fully covered. For uninsured users weighing options, a five-year hormonal IUD amortises to less than a pack of pills per month.

Insertion: What the Experience Is Like

Insertion takes five to ten minutes in most cases. The clinician first measures uterine depth with a thin probe (the 'sound'), then passes the folded IUD through the cervical canal using an insertion tube. A speculum holds the vagina open during the procedure. Most people experience moderate cramping — similar to strong period pain — during and immediately after insertion. Taking an over-the-counter NSAID such as ibuprofen one hour before the appointment can help. Severe pain, fainting, or pain that worsens significantly after leaving the clinic should be reported promptly.

IUDs can be inserted at any point in the menstrual cycle, though many clinicians prefer insertion during or just after menstruation when the cervix is slightly more open. Insertion immediately after childbirth (within 48 hours) or during a caesarean section is safe and has low expulsion rates. After a first-trimester miscarriage or abortion, immediate insertion is appropriate and recommended by the WHO. Contrary to historic guidance, IUDs are safe and suitable for people who have never been pregnant.

Managing Side Effects: Bleeding and Cramping Patterns

The copper IUD commonly causes heavier, longer, and more painful periods, particularly in the first three to six months. For many users the pattern settles thereafter, but for some it remains heavier than pre-insertion baseline. NSAIDs taken during menstruation reduce both blood loss and pain. People with pre-existing heavy periods, fibroids, or severe dysmenorrhoea may find the copper IUD worsens symptoms significantly; a hormonal IUD is often the better choice in these cases.

Hormonal IUDs do the opposite: most users experience lighter periods, shorter periods, or no periods at all after the first few months. Irregular spotting in the first three to six months is normal and almost universal. Communicating this to users before insertion dramatically improves satisfaction, since unplanned spotting is the primary reason people request early removal. The absence of periods on a hormonal IUD does not indicate pregnancy — it is a direct result of endometrial thinning.

Expulsion, Perforation, and Infection Risks

Expulsion — the IUD being partially or fully pushed out by uterine contractions — occurs in approximately 2–10 % of users, most commonly in the first year and most often in nulliparous people and those who had insertion within the first 48 hours postpartum (delayed from 48 hours to four weeks). Checking for the device's retrieval strings monthly (or after each period) allows users to detect expulsion early. Perforation during insertion is rare — approximately 1 in 1,000 insertions — and is more likely when performed by less experienced clinicians.

IUDs do not increase long-term infection risk in people who are not at elevated STI risk. The small elevation in pelvic inflammatory disease risk occurs in the first 20 days after insertion and is thought to be related to introducing bacteria from the cervix into the uterus during the procedure, not ongoing IUD presence. Screening for chlamydia and gonorrhoea before or at insertion is standard practice in most settings.

Who Benefits Most from Each Type

The copper IUD is an excellent choice for anyone who prefers to avoid hormones entirely — whether due to personal preference, hormone-sensitive conditions, migraine with aura, cardiovascular risk factors, or breastfeeding. It is also the clear choice when emergency contraception is needed within five days of unprotected sex. The hormonal IUD is often preferred by people with heavy, painful periods, endometriosis, or adenomyosis, since it reduces bleeding and pain substantially.

Myths Worth Dispelling

Myth: IUDs cause infertility. This has been thoroughly disproven. Fertility returns to pre-IUD baseline within the first cycle after removal. Myth: IUDs are only for people who have given birth. Guidelines from the American College of Obstetricians and Gynecologists, the Faculty of Sexual and Reproductive Healthcare in the UK, and the WHO all affirm that IUDs are appropriate for adolescents and nulliparous individuals. Myth: You can feel the IUD during sex. The device sits inside the uterus; neither partner should feel it. Partners occasionally notice the retrieval strings, which can be trimmed by the clinician.

Frequently Asked Questions

Q: Can I use tampons or a menstrual cup with an IUD? A: Tampons are fine. Menstrual cups can be used but require extra care when removing — pulling the cup out without first breaking the suction could theoretically dislodge an IUD. Check strings after each use.

Q: Will I know if my IUD has moved? A: Not always. Some dislocations are silent. Checking strings monthly is important. If strings feel longer, shorter, absent, or if you feel the hard plastic of the device at the cervix, see a clinician promptly and use backup contraception in the meantime.

Q: Does the hormonal IUD affect mood? A: Systemic levonorgestrel levels with a hormonal IUD are very low — roughly a tenth of those from the combined pill. Large studies have not found a significant causal link between hormonal IUDs and depression or mood disorders, though individual responses vary. If mood changes emerge after insertion and no other explanation is found, removal is a reasonable option.

Q: Can an IUD be used during perimenopause? A: Yes. The Mirena is licensed in several countries for endometrial protection in women using oestrogen HRT during perimenopause or menopause. The copper IUD inserted at 40 or older can remain in place until menopause is confirmed.

Hormonal and Copper IUDs Compared