The copper IUD and the Mirena IUD are two of the most common contraceptive methods today, as they have a high rate of effectiveness, and after placement they can be used for several years, becoming one of the cheapest available. Thus, it is convenient to make a comparison between both types of IUDs to choose the one that is best for you. While they both look similar and share some features, there are differences in how they work that you should be aware of. Both are small T-shaped devices that are placed inside the uterus, leaving a few threads that serve to check if the IUD has moved and remove it if necessary.

The Similarities and Differences between IUD Types

  • However, the main difference between the two is that while the copper IUD has a purely mechanical function, the Mirena IUD has a hormonal component. For this reason, although many women can choose one or the other interchangeably, there is an ideal profile of a woman for each type of IUD.
  • The copper IUD, since it does not contain hormones, is the ideal type of IUD for women who are sensitive to hormonal imbalances, and it is also very common during lactation. It regulates the menstrual cycle and usually has serious side effects, although it is important to check that you are not allergic to copper and keep in mind that this method increases the duration and abundance of menstruation, so it is not recommended for women with hypermenorrhea.
  • By contrast, the Mirena IUD is a hormonal contraceptive. This means that, in addition to the physical block that it exerts like the copper IUD, it complements its action by releasing progesterone. Some women are very sensitive to its side effects, especially during the first months, so it is advisable to be well informed about the differences between the hormonal IUD and the copper one so that you can make the most appropriate decision for your situation.
## Choosing the right IUD: clinical decision-making and patient scenarios Choosing between a copper IUD and a levonorgestrel-releasing IUD (Mirena and similar brands) should be individualized. Below I describe practical decision points, contraindications, and examples from clinical practice to illustrate how I make recommendations. - Key decision factors to review with patients: - Desire for future fertility and planned timing of pregnancy (both IUDs have rapid return of fertility after removal). - Menstrual history: heavy or painful periods versus light or absent bleeding. - Sensitivity or contraindications to hormones (e.g., current or recent breast cancer, history of hormone-sensitive conditions). - Breastfeeding status (hormonal systemic exposure is low with levonorgestrel IUDs; both are acceptable in most breastfeeding patients). - Allergy to copper or known Wilson disease (a copper IUD is contraindicated). - STI risk and recent pelvic infections. - Tolerance for potential side effects (initial irregular bleeding vs heavier menses). - Preference for emergency contraception capability (copper IUD can be used as emergency contraception). Real-world examples: - Example 1 — Heavy periods and anemia: A 38-year-old woman presents with heavy, painful bleeding and iron-deficiency anemia. She wants contraception and to reduce bleeding. I recommended a levonorgestrel IUD (Mirena). Within 3 months she reported lighter menses and, by 6–12 months, near-amenorrhea with improved hemoglobin. Clinical point: **Mirena is the preferred option for menorrhagia** when the patient wants contraception and reduction of bleeding. - Example 2 — Breastfeeding, immediate contraception: A 30-year-old postpartum patient who is exclusively breastfeeding at 6 weeks postpartum wants long-term contraception and prefers a hormone-free option. After counseling, she chose a copper IUD. She tolerated insertion and remained amenorrheic while breastfeeding, but was counseled that once lactation decreased she could experience heavier periods. Clinical point: **Both IUDs are options while breastfeeding, but the copper IUD is sometimes chosen to avoid any hormonal exposure.** - Example 3 — Intolerance to systemic hormones: A 26-year-old with migraine with aura (contraindication to combined estrogen contraception) sought a non-estrogen option. We discussed Mirena (progestin-only) and copper; she preferred Mirena for its reduction in bleeding and lower cramping long-term. Clinical point: **Levonorgestrel IUDs are suitable for those who cannot use estrogen.** Contraindications summarised (important to review before insertion): - Suspected or active pregnancy. - Current pelvic inflammatory disease (PID) or untreated cervicitis. - Known current breast cancer (for levonorgestrel IUD). - Known copper allergy or Wilson disease (for copper IUD). - Abnormal uterine anatomy preventing device placement (e.g., significant distortion from fibroids). For more on managing heavy periods and other menstrual issues, see [related topic](/blog). ## Insertion, follow-up and troubleshooting: step-by-step guidance Insertion and follow-up processes are where patient experience and outcomes can be optimized. Below are evidence-based, actionable steps I use in practice. Preparation before insertion: - Confirm no pregnancy (pregnancy test if menses timing unclear). - Screen for STIs if high risk or presence of symptoms (chlamydia/gonorrhea). If positive, treat before inserting or treat promptly and discuss risks. - Discuss pain control options: pre-medicate with ibuprofen 400–600 mg one hour before insertion (unless contraindicated). Some patients benefit from a single dose of oral analgesic; others may need local anesthesia or conscious sedation in rare cases. - Provide counseling on what to expect during and after the procedure, potential side effects, expulsion signs, and when to seek care. Insertion technique (practical points to reduce discomfort and complications): - Position the patient in lithotomy, perform a pelvic exam to assess uterus size and position. - Use a speculum and cleanse cervix. A tenaculum is applied to stabilize the cervix (local anesthetic can be used at the clinician’s discretion). - Sound the uterus to measure depth—this step reduces risk of perforation. - Load and insert the device per manufacturer instructions, then trim the threads to ~3 cm beyond the cervix. - Observe the patient for 10–15 minutes; many centers recommend monitoring for a short time for vasovagal reactions. Expected immediate side effects and management: - Cramping and light spotting are common. Recommend NSAIDs (ibuprofen or naproxen) and a heating pad. Most symptoms settle within 24–72 hours. - Heavy bleeding or severe pain soon after insertion may indicate perforation or expulsion—seek urgent evaluation. Follow-up schedule and self-checks: - Routine follow-up at 4–12 weeks is typical, though not always mandatory. Many patients can be advised to check threads monthly after menses. - Instruction to feel for the threads: Wash hands, insert a clean finger into the vagina and feel towards the cervix. You should feel thin threads; if you feel the device itself (hard plastic) or cannot feel threads at all, see your clinician. - Long-term annual checks with routine gynecologic care, or sooner if problems occur. Troubleshooting common problems — practical steps: - Partial expulsion: If part of the device is visible in the cervix or vagina, the IUD should be removed and replaced if contraception is still desired. - Suspected pregnancy with IUD in place: Evaluate urgently. If pregnancy is intrauterine and strings visible, remove the IUD if the patient desires to continue pregnancy, as removal reduces infection risk and miscarriage risk later. If removed and pregnancy continues, close follow-up is needed. - Infection after insertion: Early post-insertion PID is uncommon but treat promptly with appropriate antibiotics. Consider device removal only if infection does not respond to therapy. - Perforation: Rare (~1 per 1,000 insertions). If suspected (severe pain at insertion, inability to find threads, or device not seen on ultrasound), obtain imaging and consult gynecology for removal. If you later need supplies or products to help with menstrual care while using an IUD, visit our [shop](/shop). ## How each IUD works, effectiveness and side-effect profiles Mechanism and effectiveness: - Copper IUD (e.g., ParaGard): - Mechanism: copper is spermicidal and creates a local inflammatory environment toxic to sperm and oocytes. It does not rely on hormones. - Effectiveness: Typical first-year failure rate is approximately 0.6–0.8% (less than 1%). - Duration: Up to 10–12 years depending on the specific device. - Levonorgestrel IUD (e.g., Mirena, Kyleena, Skyla — Mirena typically refers to 52 mg levonorgestrel device): - Mechanism: releases levonorgestrel locally, thickening cervical mucus, reducing sperm motility and function, and thinning the endometrium. - Effectiveness: First-year failure rate ~0.1–0.5% (very low). - Duration: Mirena is FDA-approved for 5–8 years depending on indication; other LNG devices vary (3–5 years). Common side effects and timeline: - Copper IUD: - Short-term: cramping and spotting in the first 1–3 months. - Long-term: heavier, longer periods and increased cramps; may worsen menorrhagia — not ideal for people with existing heavy bleeding. - Levonorgestrel IUD: - Short-term: irregular spotting/bleeding in first 3–6 months, occasional mood changes, breast tenderness for some. - Long-term: many users experience lighter periods or amenorrhea. Often used therapeutically for heavy bleeding and as part of endometrial protection. Risks: - Perforation: rare (~0.1–1 per 1,000). - Expulsion: risk highest within the first 3 months; rates vary by age and postpartum status (2–10% overall). - Infection: small increase in PID risk in the 20 days following insertion if an STI is present at insertion; long-term infection risk is not increased. - Hormonal side effects with levonorgestrel IUD are typically localized (lower systemic exposure than oral progestins) but can include mood changes, acne, breast tenderness, and weight concerns (weight gain is not consistently associated with LNG IUDs in clinical data). ## Practical advice for patients — what I tell my patients in clinic - Pain management: Take ibuprofen 400–600 mg about one hour before insertion (unless contraindicated). Consider an antacid if NSAIDs upset your stomach. A heating pad after insertion helps cramping. - Resume sexual activity when comfortable; no required delay after IUD insertion for contraception efficacy (immediately effective for copper IUD if inserted >7 days after ovulation; LNG-IUD is effective immediately if inserted within the first 7 days of the menstrual cycle, otherwise backup contraception for 7 days). - Check your threads monthly after menses. If you cannot feel threads or feel the device itself, contact your clinician. - If you have unprotected intercourse and have risk of pregnancy, remember the copper IUD can be used as emergency contraception if inserted within 5 days (120 hours) — it's the most effective emergency option and prevents future pregnancies for years. - Plan removal proactively: If you want to conceive, removal is immediate and fertility returns quickly. Book removal ahead of time if planning pregnancy. Real patient scenario — expulsion and next steps: - A 21-year-old athlete had a copper IUD placed. Two months later she felt increased cramping and noted heavier bleeding; on exam we found partial expulsion. We removed the device, discussed reinsertion versus alternative contraception, and she opted for reinsertion with extra counseling on spotting and activity modifications. Clinical point: vigorous physical activity, very heavy menses, and younger age are associated with higher expulsion rates. ## Special situations and my recommendations - Adolescents and nulliparous patients: Both types of IUDs are appropriate. Counseling should emphasize expulsion risks and follow-up. Many guidelines support IUDs as first-line long-acting reversible contraception for adolescents. - Postpartum timing: - Immediate postpartum insertion (within 10 minutes of delivery) is possible, but expulsion risk is higher. - Delayed insertion at 6 weeks postpartum is commonly performed; for breastfeeding patients, both devices are acceptable. - Women with heavy menstrual bleeding or fibroids: - Mirena often reduces bleeding and is first-line medical therapy for heavy menstrual bleeding and for protection of the endometrium in those taking systemic estrogen. - Copper IUD may worsen bleeding and is usually avoided when menorrhagia is present. - Women with history of PID: IUDs are not recommended for women with current PID. If treated and infection resolved, IUD insertion can be offered. - Copper allergy / Wilson disease: avoid copper IUD. ## When to call your clinician — red flags - Severe, persistent abdominal pain after insertion (possible perforation). - Fever, chills, abnormal vaginal discharge consistent with infection. - Sudden heavy bleeding or passage of IUD pieces (expulsion). - Symptoms of pregnancy or a positive pregnancy test. - Inability to feel IUD strings or feeling the hard plastic device. ## FAQ ### Can I get pregnant with an IUD? Yes, though both the copper and levonorgestrel IUDs are among the most effective reversible contraceptives. The levonorgestrel IUD has a first-year failure rate of roughly 0.1–0.5%, and the copper IUD about 0.6–0.8% in the first year. If pregnancy occurs with an IUD in place, seek evaluation immediately — the risk of ectopic pregnancy is low overall but if pregnancy occurs it has a higher relative chance of being ectopic. If the strings are visible and you desire to continue the pregnancy, removal of the IUD reduces the risk of adverse outcomes. ### Which IUD is best if I have heavy periods? A levonorgestrel IUD (Mirena) is typically the best choice for heavy menstrual bleeding. It thins the uterine lining and often reduces bleeding substantially; many users have significantly lighter periods or become amenorrheic. The copper IUD is usually not recommended for women with heavy bleeding because it can increase bleeding and cramping. ### Is an IUD safe while breastfeeding? Yes. Both copper and levonorgestrel IUDs are considered safe for breastfeeding women. Levonorgestrel released by a Mirena is mostly local with minimal systemic absorption and is not known to adversely affect milk production or infant growth. If you prefer to avoid any hormone exposure, a copper IUD is hormone-free and appropriate while breastfeeding. ### Can the IUD come out during sex or exercise? Partial expulsion can occur, most commonly within the first 3 months after insertion. In many cases partners do not feel the IUD during sex, and the threads are generally soft and not bothersome. If you or your partner feel a hard plastic sensation, or if you note increased cramping or unusual bleeding after sex or exercise, check the threads and see your clinician. If the device has partially or completely expelled, you will need removal and discussion of replacement. ### Will my fertility return after I have an IUD removed? Yes. Fertility returns rapidly after removal of either type of IUD. Conception can occur in the first menstrual cycle after removal. If you plan pregnancy, schedule removal when convenient and expect normal return to fertility unless other fertility issues exist. --- If you want further reading on contraceptive comparisons and long-acting reversible contraception (LARC), see our extended resources in [related topic](/blog). If you need supplies related to menstrual health or post-insertion care, check our [shop](/shop). Category: Health Issues Topic: Types of IUD: characteristics of each contraceptive method