There’s no single “best” IUD for everyone. The right choice depends on whether you want hormone-free contraception, lighter periods, or the longest possible protection. All five IUDs available in the U.S. are over 99% effective at preventing pregnancy, so the real differences come down to hormone dose, device size, how long they last, and how they affect your period.
Five IUDs are currently on the market: four hormonal options (Mirena, Liletta, Kyleena, and Skyla) and one copper option (Paragard). Here’s how they compare and what actually matters when choosing between them.
How Hormonal and Copper IUDs Work Differently
Hormonal IUDs are T-shaped plastic devices that release a small, steady amount of a synthetic hormone called levonorgestrel directly into the uterus. This thins the uterine lining and thickens cervical mucus, making it difficult for sperm to reach an egg or for a fertilized egg to implant. The hormone stays mostly local, so the amount circulating through your bloodstream is far lower than with birth control pills or patches.
The copper IUD (Paragard) contains no hormones at all. Instead, copper wire wrapped around the plastic frame releases copper ions that are toxic to sperm. It’s the only hormone-free IUD available and the only option for people who want to avoid hormonal contraception entirely.
The Four Hormonal IUDs Compared
The hormonal IUDs differ mainly in how much hormone they contain, how large they are, and how long they’re approved to work.
Mirena carries the highest hormone reservoir at 52 mg and releases about 20 micrograms per day initially, tapering to around 10 micrograms after five years. It measures 32mm by 32mm. Mirena is FDA-approved for up to 8 years of use and is the only IUD with a specific FDA indication for treating heavy menstrual bleeding, making it a strong choice if heavy periods are a major concern for you.
Liletta is nearly identical to Mirena in size (32mm by 32mm) and hormone load (52 mg reservoir, releasing about 18.6 micrograms per day initially). It’s also approved for up to 8 years. Liletta was designed as a lower-cost alternative and is commonly stocked at public health clinics and Title X programs, so it tends to be the most accessible option if cost is a factor.
Kyleena is physically smaller (28mm by 30mm) and contains a lower hormone reservoir of 19.5 mg, releasing about 17.5 micrograms per day at first and dropping to 7.4 micrograms after five years. It’s approved for up to 5 years. The smaller frame can make insertion more comfortable, particularly for people with a smaller uterus.
Skyla is the smallest hormonal IUD, also measuring 28mm by 30mm, with the lowest hormone dose of all: a 13.5 mg reservoir releasing about 14 micrograms per day, decreasing to 5 micrograms after three years. It’s only approved for 3 years, giving it the shortest lifespan of any IUD on the market.
Paragard: The Hormone-Free Option
Paragard is the largest IUD at 32mm by 36mm and is approved for up to 10 years, the longest duration of any IUD. Because it’s entirely hormone-free, it won’t cause hormone-related side effects like mood changes, acne, or nausea. Your natural menstrual cycle continues unchanged in terms of hormonal patterns.
The tradeoff is that Paragard commonly makes periods heavier and cramps more intense, especially in the first several months. For people who already have heavy or painful periods, this can be a dealbreaker. But for those who want long-term, set-it-and-forget-it contraception without any hormones, it’s the only IUD that fits that description.
How Each IUD Affects Your Period
This is often the deciding factor. Hormonal IUDs generally make periods lighter over time, and many users eventually stop getting a period altogether. The higher the hormone dose, the more likely this is. Mirena and Liletta, with their 52 mg reservoirs, have the highest rates of causing periods to stop completely. Kyleena and Skyla, with lower doses, tend to lighten periods but are less likely to eliminate them.
Paragard does the opposite. Heavier menstrual bleeding is a well-documented effect of copper IUDs. If lighter periods or no periods sound appealing, a hormonal IUD is the better fit. If you’d rather keep a regular cycle and avoid hormones, Paragard is worth the adjustment period.
Who Can Get an IUD
All five IUDs are safe and effective for people who haven’t had children. This is a common misconception that dates back to older labeling. Mirena’s prescribing information still recommends it for people who have had at least one child, but that recommendation isn’t reflected in the other brands’ labels or in current clinical guidelines. Professional medical organizations recommend IUDs routinely for people of all parities.
Kyleena and Skyla, with their smaller frames, were specifically designed to fit more easily in a smaller uterus. That said, clinical evidence hasn’t shown that smaller devices actually work better or cause fewer problems in people who haven’t given birth. The choice between a smaller and larger IUD is reasonable to discuss with your provider, but don’t assume you need a small one just because you haven’t been pregnant.
Risks and Complications
IUDs are among the safest forms of contraception, but they do carry some risks. The two main complications are expulsion (the device partially or fully slipping out) and perforation (the device pushing through the uterine wall).
Expulsion happens in about 2.3% of users within the first year and roughly 4.5% to 4.8% within five years. The rates are essentially the same for hormonal and copper IUDs. You can check for expulsion by feeling for the IUD’s strings, which hang through the cervix. If the strings feel longer or shorter than usual, or you can feel the hard plastic of the device itself, contact your provider.
Perforation is much rarer. Within the first year, it occurs in about 0.2% of IUD users. By five years, the cumulative rate is around 0.6%. Hormonal IUDs carry a slightly higher perforation risk than copper IUDs, though both rates are very low. Pain and infection can occur with either type at similar rates.
Because hormonal IUDs release a small amount of hormone, some users experience side effects like acne, nausea, mood changes, or weight fluctuations. These tend to be milder than with systemic hormonal methods like the pill, since the hormone is released locally rather than throughout the body.
What Insertion Feels Like
IUD insertion is a quick procedure, typically taking just a few minutes. Most people experience cramping that ranges from mild to sharp during placement, with discomfort that usually fades within a day or two. Current CDC guidelines note that a local anesthetic (lidocaine, either injected near the cervix or applied topically) can help reduce pain during insertion. Routine use of cervical-softening medication before insertion is not recommended, though it may be offered if a previous insertion attempt failed.
Cramping and spotting in the days and weeks after insertion are normal. Most providers schedule a follow-up visit to confirm the device is properly positioned.
Cost and Insurance Coverage
IUD prices range from $0 to $1,800 for the device alone, not including the provider visits for insertion, follow-up, and eventual removal. Under the Affordable Care Act, most private insurance plans cover IUDs with no cost-sharing. About 69% of privately insured women pay nothing out of pocket for IUD insertion. Among those who do pay, the average cost-sharing is around $41.
Without insurance, copper IUDs tend to cost less than hormonal ones. Over a five-year span, a copper IUD including all related visits typically runs less than any hormonal option. Liletta is generally the most affordable hormonal IUD, as it was specifically developed for broader access through public health programs.
Choosing the Right IUD for You
If you want the longest protection with no hormones, Paragard lasts up to 10 years and keeps your natural cycle intact, though periods will likely be heavier. If you want lighter periods or have heavy menstrual bleeding, Mirena or Liletta offer the highest hormone dose, the best chance of stopping periods, and up to 8 years of use. If you prefer a lower hormone dose or a smaller device, Kyleena provides 5 years of protection. Skyla delivers the lowest hormone exposure but only lasts 3 years, making it the least cost-effective option per year of use.
All five are over 99% effective. The “best” IUD is the one that matches your priorities: hormone-free versus lighter periods, device size, how many years you want coverage, and what you can access at a price that works for you.