The Short Answer
Both types of IUD are over 99% effective, last for years, and require no daily effort. The key difference is hormones. The hormonal IUD (Mirena, Kyleena, Liletta, Skyla) releases progestin locally, which typically makes periods lighter or stops them. The copper IUD (Paragard) is completely hormone-free but often makes periods heavier and cramps stronger. Choose based on whether you want hormonal benefits (lighter periods, fewer cramps) or prefer to avoid hormones entirely.
Key Points:
- Both are 99%+ effective with no daily action required
- Hormonal IUD: lighter or absent periods, local progestin, lasts 3-8 years
- Copper IUD: no hormones, heavier periods possible, lasts 10-12 years
- Insertion procedure is the same for both
- Copper IUD can double as emergency contraception (within 5 days)
Comparison Table
| Factor | Hormonal IUD | Copper IUD |
|---|---|---|
| Brands | Mirena, Kyleena, Liletta, Skyla | Paragard |
| Effectiveness | 99.8% | 99.2% |
| Hormones | Progestin (local) | None |
| Duration | 3-8 years (varies by brand) | 10-12 years |
| Effect on periods | Lighter or absent | Often heavier, stronger cramps |
| Insertion pain | Moderate (brief) | Moderate (brief) |
| Emergency contraception | No | Yes (within 5 days) |
| Cost (without insurance) | $0-1,300 | $0-1,300 |
How the Hormonal IUD Works
The hormonal IUD sits in the uterus and releases a small amount of levonorgestrel (a type of progestin) directly into the uterine lining. This thins the uterine lining (reducing menstrual bleeding), thickens cervical mucus (blocking sperm), and may partially suppress ovulation (varies by brand).
Because the hormone is delivered locally, blood levels of progestin are much lower than with pills or the shot. Most users still ovulate normally.
- Mirena: up to 8 years (highest progestin dose)
- Liletta: up to 8 years
- Kyleena: up to 5 years (lower dose, smaller frame)
- Skyla: up to 3 years (lowest dose, smallest frame)
How the Copper IUD Works
The copper IUD is wrapped in copper wire. Copper ions create an inflammatory response in the uterus that is toxic to sperm, preventing fertilization. No hormones are involved at any point. It starts working immediately after insertion and can also be used as emergency contraception if inserted within 5 days of unprotected sex.
Period Changes - The Biggest Difference
Hormonal IUD
- First 3-6 months: irregular spotting and light bleeding are common
- After 6 months: periods typically become very light
- After 1 year: about 20% of Mirena users stop getting periods entirely
- Reduced cramps for most users
Copper IUD
- First 3-6 months: periods are often heavier and longer, cramps may be stronger
- After 6 months: flow usually decreases but may remain heavier than your pre-IUD baseline
- Periods continue at their natural cycle length
- Cramps may remain stronger than before insertion
If heavy or painful periods are already an issue for you, the copper IUD may not be the best fit. Conversely, if you want to keep having regular periods as a monthly reassurance, the copper IUD preserves that signal.
Who Should Consider the Hormonal IUD
- You want lighter periods or no periods
- You have heavy or painful periods and want relief
- You are open to a small amount of local hormone
- You want long-term, low-maintenance contraception
- You have endometriosis (hormonal IUDs can help manage symptoms)
Who Should Consider the Copper IUD
- You want to avoid hormones completely
- You have had negative reactions to hormonal birth control
- You want the longest-lasting option (10-12 years)
- You want a method that can also serve as emergency contraception
- You have naturally light periods and are not concerned about increased flow
Insertion and Removal
The procedure is identical for both types:
- Takes about 5-10 minutes in a provider's office
- A speculum is used to visualize the cervix; the IUD is inserted through the cervical canal
- Brief cramping during insertion (most intense for a few seconds)
- Pain management options: OTC pain relievers before the appointment, cervical numbing, or in some cases sedation
- Removal is usually faster and less uncomfortable than insertion
Frequently Asked Questions
Can I feel the IUD during sex?
The IUD itself sits inside the uterus and cannot be felt. The strings hang slightly through the cervix. Occasionally a partner may feel the strings, but your provider can trim them shorter if this is an issue.
What if I want it removed early?
Both types can be removed at any time by a provider. Fertility returns quickly - you can get pregnant in the same cycle after removal.
Can I use a menstrual cup with an IUD?
Generally yes, but break the suction seal before removing the cup to avoid pulling on the IUD strings. Some providers recommend waiting 1-2 cycles after insertion before using a cup.
Does the copper IUD cause copper toxicity?
No. The amount of copper released is very small and well within safe levels. Blood copper levels in copper IUD users are within the normal range.