Hormonal vs Copper IUD: Key Differences Explained

How do hormonal and copper IUDs prevent pregnancy?

Hormonal IUDs release a small amount of levonorgestrel, a progestin, directly into the uterus. The hormone thickens cervical mucus (making it harder for sperm to reach an egg), thins the uterine lining, and in some users suppresses ovulation partially. The systemic hormone level is very low — much lower than oral contraceptive pills — because the release is local 1Ref 1American College of Obstetricians and Gynecologists (2019).ACOG Practice Bulletin No. 206: Use of Hormonal Contraception in Women With Coexisting Medical Conditions.IUD use regardless of childbirth history; therapeutic use of hormonal IUD for heavy bleeding and endometriosis.

The copper IUD contains no hormones. Copper ions are toxic to sperm, impairing motility and fertilization. The copper IUD also affects the uterine environment in ways that prevent fertilization. It does not prevent ovulation. Because it works immediately upon insertion, it is also highly effective as emergency contraception when inserted within five days of unprotected sex — with a pregnancy rate of less than 0.1% across pooled data from 42 studies 2Ref 2Goldstuck ND, Wildemeersch D (2015).Practical Advice for Emergency IUD Contraception in Young Women.Copper IUD as emergency contraception: systematic review of 42 studies shows pregnancy rate of 0.09% when inserted within 5 days of unprotected intercourse; unaffected by BMI or timing within the 5-day window.

How do they compare on periods?

This is often the most practically important difference:

Hormonal IUDs: Most people experience lighter periods, and many see periods stop entirely within several months of insertion. This is often welcome, especially for those with heavy or painful periods. Irregular spotting is common in the first three to six months while the body adjusts.

Copper IUD (Paragard): Periods typically become heavier, longer, and crampier — especially in the first several months after insertion. For people who already have heavy periods, this can be a meaningful concern. For others with normal or light periods, the increase in flow may be manageable. The effect on flow tends to lessen somewhat after the first year.

How long does each type last?

Hormonal IUDs vary by brand and hormone dose: - Mirena: approved for up to 8 years - Kyleena: up to 5 years - Liletta: up to 8 years - Skyla: up to 3 years (smallest, designed for people who have not had children)

Copper IUD (Paragard): Approved for up to 10 years, though studies support effective use for longer — sometimes cited as 12 or more years in research settings.

All IUDs are reversible: fertility returns promptly after removal for all types.

Who might prefer a hormonal IUD?

A hormonal IUD may suit you well if: - You want lighter periods or period elimination - You have endometriosis or painful, heavy periods — hormonal IUDs are used therapeutically for both and are considered a first-line treatment option 1Ref 1American College of Obstetricians and Gynecologists (2019).ACOG Practice Bulletin No. 206: Use of Hormonal Contraception in Women With Coexisting Medical Conditions.IUD use regardless of childbirth history; therapeutic use of hormonal IUD for heavy bleeding and endometriosis3Ref 3American College of Obstetricians and Gynecologists (2019).Screening and Management of Bleeding Disorders in Adolescents With Heavy Menstrual Bleeding: ACOG Committee Opinion, Number 785.Levonorgestrel-releasing IUD (hormonal IUD) as an effective first-line treatment for heavy menstrual bleeding, including in adolescents - You want long-acting but reversible contraception with minimal hormonal side effects compared to pills - You prefer something you do not have to think about daily

Some people do experience progestin-related side effects — mood changes, acne, or headaches — though systemic absorption is low and these are less common than with pills.

Who might prefer a copper IUD?

A copper IUD may suit you well if: - You want completely hormone-free contraception - You have had side effects from hormonal contraceptives and want to avoid them entirely - You are using it as emergency contraception (it must be inserted within 5 days of unprotected sex) - You are breastfeeding (both types are safe during breastfeeding, but some prefer hormone-free options) - You have certain health conditions that make estrogen-containing contraceptives inadvisable (the copper IUD contains no hormones at all)

The key practical consideration is whether heavier periods are acceptable.

What is IUD insertion like?

Insertion is an in-office procedure that takes a few minutes. Most people experience cramping during and after insertion, ranging from mild to significant. The discomfort typically resolves within a few hours to a day. Over-the-counter pain medication taken beforehand can help. Some providers offer additional options for discomfort management.

IUDs can be inserted regardless of whether you have had children — guidelines no longer restrict IUD use based on childbirth history 1Ref 1American College of Obstetricians and Gynecologists (2019).ACOG Practice Bulletin No. 206: Use of Hormonal Contraception in Women With Coexisting Medical Conditions.IUD use regardless of childbirth history; therapeutic use of hormonal IUD for heavy bleeding and endometriosis.