LARC stands for long-acting reversible contraception, a category of birth control that includes IUDs and the arm implant. These methods are more than 99% effective at preventing pregnancy, making them the most reliable forms of reversible birth control available. Once placed by a provider, they work continuously for years without requiring you to remember a daily pill, replace a patch, or use anything before sex.
Why LARCs Are So Effective
LARCs are roughly 20 times more effective than birth control pills, the patch, or the vaginal ring. The reason is simple: they remove the possibility of user error. A pill only works if you take it every day at roughly the same time. A ring only works if you replace it on schedule. An IUD or implant, once in place, just works. There’s nothing to forget, refill, or track.
With typical, real-world use, fewer than 1 in 100 people using a LARC will become pregnant in a given year. That failure rate is virtually identical to the “perfect use” rate because there’s no gap between using the method correctly and using it at all.
Types of LARCs
There are two broad categories: IUDs, which sit inside the uterus, and the implant, which goes in the upper arm. Within the IUD category, you can choose between hormonal and non-hormonal (copper) options.
Hormonal IUDs
A hormonal IUD is a small, T-shaped plastic device placed inside the uterus. It releases a tiny, steady amount of a progestin hormone that thins the uterine lining and thickens cervical mucus, making it difficult for sperm to reach an egg. Most people who use one continue to ovulate, but menstrual bleeding becomes lighter over time, and some people stop getting periods altogether.
Four hormonal IUDs are currently available, and they differ mainly in how long they last:
- Mirena: up to 8 years
- Liletta: up to 8 years
- Kyleena: up to 5 years
- Skyla: up to 3 years
Because only a small amount of hormone is released locally, systemic side effects are less common than with pills or the patch. Some people do experience headaches, breast tenderness, mood changes, nausea, or temporary ovarian cysts, but these tend to be mild.
Copper IUD
The copper IUD (ParaGard) is the only hormone-free LARC option. It’s a T-shaped plastic frame wrapped in copper wire. The copper changes the uterine environment in a way that impairs sperm function and movement, preventing sperm from reaching and fertilizing an egg. It lasts up to 10 years.
The trade-off for going hormone-free is that periods often become heavier and crampier, especially in the first several months. For people who want long-term protection without any hormonal effects, though, it’s the only device in this category.
The Implant
The contraceptive implant (Nexplanon) is a flexible plastic rod about the size of a matchstick. A provider inserts it just under the skin of your upper arm, where it releases a steady dose of a progestin hormone. It works primarily by stopping ovulation, while also thickening cervical mucus and altering the uterine lining as backup mechanisms. It lasts up to 3 years.
Changes in bleeding patterns are the most common side effect. Some people experience lighter or absent periods, while others have irregular, prolonged, or more frequent bleeding. Headaches, breast pain, and digestive discomfort are also reported but generally not severe.
What Insertion and Removal Feel Like
IUD insertion is an in-office procedure that typically takes just a few minutes. A provider uses a speculum, measures the uterus, and places the device through the cervical opening. The sensation ranges from a pinch to strong cramping, and it’s over quickly. Pain management options should be discussed beforehand. Approaches vary from patient to patient, and your provider can help you decide what’s appropriate. Some people feel fine immediately afterward, while others have cramping for a few hours or days.
Implant insertion is even simpler. After numbing a small area on the inner upper arm, the provider uses a special applicator to slide the rod just beneath the skin. The whole process takes about a minute. You may have bruising or soreness at the site for a few days.
Removal for both devices is generally quicker and less uncomfortable than insertion. An IUD is removed by gently pulling the strings that hang through the cervix. The implant is removed through a tiny incision after the area is numbed. Either procedure can be done during a routine office visit.
How Quickly Fertility Returns
One of the key advantages of LARCs is that fertility bounces back fast after removal. Research from Boston University found that people who used IUDs or implants returned to fertility in an average of about two menstrual cycles. That was the shortest wait among all contraceptive methods studied. If you’re planning a pregnancy, you don’t need to stop using a LARC months in advance to “clear your system.” Ovulation can resume within days to weeks of removal.
Possible Complications
Serious complications with IUDs are uncommon. The most notable risk is expulsion, where the device partially or fully slips out of position. This happens in roughly 2% to 10% of users during the first year. You can check for proper placement by feeling for the IUD strings periodically. If the strings seem shorter, longer, or missing, contact your provider.
Uterine perforation, where the device pushes through the uterine wall during insertion, is rare. Infection risk is also low and is mainly limited to the first few weeks after placement. The implant carries even fewer procedural risks since it sits in the arm rather than the uterus, though migration of the rod is a rare possibility.
Cost and Insurance Coverage
The upfront cost of a LARC can be several hundred to over a thousand dollars without insurance. However, most health insurance plans in the U.S. are required to cover FDA-approved contraceptive methods, including IUDs and implants, with no copay, coinsurance, or deductible when you use an in-network provider. This applies to plans sold through the Health Insurance Marketplace and most employer-sponsored plans.
The main exception is plans sponsored by certain religious employers, such as churches, which may be exempt from the contraceptive coverage requirement. Some non-profit religious organizations have a workaround where a third-party administrator covers contraceptive costs separately, so you still get access without out-of-pocket expense.
When you spread the cost over years of use, LARCs are among the most affordable contraceptive options available, even at full price. A device that lasts 8 to 10 years costs far less per month than a prescription refilled every 30 days.
Who Can Use a LARC
LARCs are considered safe for a wide range of people, including teenagers and those who have never been pregnant. The CDC publishes medical eligibility guidelines to help providers determine which contraceptive methods are appropriate for people with specific health conditions, but the overall goal of those guidelines is to remove unnecessary barriers to access. Very few medical conditions rule out LARC use entirely. Your provider can review your health history and help you choose between a hormonal or copper option based on your preferences and any relevant conditions.