The implant is a tiny, flexible plastic rod placed just under the skin of your upper arm that releases a low, steady dose of a progestin hormone to prevent pregnancy. Sold under the brand name Nexplanon, it’s one of the most effective birth control methods available, with a failure rate near zero in clinical trials. The rod is about 4 centimeters long and 2 millimeters wide, roughly the size of a matchstick, and it works continuously for up to three years.
How the Implant Prevents Pregnancy
The implant contains 68 mg of a synthetic progestin hormone that slowly releases into your bloodstream over time. Its primary job is stopping ovulation, so your ovaries don’t release an egg each month. Without an egg, pregnancy can’t happen.
It also thickens cervical mucus, creating a barrier that makes it much harder for sperm to reach an egg in the unlikely event ovulation does occur. These two mechanisms working together are what make the implant so reliable.
How Effective It Is
The implant is over 99% effective. In a systematic review of published clinical trials, the failure rate was 0.00 per 100 women-years of use. In a large real-world study, researchers observed just one unintended pregnancy among 1,377 women-years of implant use. That makes it one of the most effective contraceptives on the market, comparable to sterilization but fully reversible.
Unlike the pill or patch, there’s no daily or weekly routine to remember, which means there’s essentially no gap between “perfect use” and “typical use” effectiveness. Body weight doesn’t appear to reduce how well it works either. Research from the Contraceptive CHOICE Project found that three-year failure rates did not vary by BMI.
How Long It Lasts
The implant is approved for three years. At the end of that period, hormone levels in the blood are still above the threshold needed for effective contraception, but the standard recommendation is replacement at the three-year mark.
Some clinical data suggests it may remain effective beyond that window. In one multi-center trial, over 200 women used the implant for at least five years with no pregnancies during years four and five. The Contraceptive CHOICE study similarly reported zero pregnancies among 123 women who completed four years of use and 34 who reached five years. That said, extended use beyond three years is not yet part of the official labeling, so your provider would need to discuss this option with you individually.
Getting It Inserted
A trained healthcare professional places the implant on the inner side of your non-dominant upper arm using a special applicator. The area is numbed with a local anesthetic first, and the actual insertion takes about 30 seconds on average. You won’t need stitches. Afterward, the site gets covered with two bandages: the outer one stays on for 24 hours, and the smaller one underneath should stay clean and dry for three to five days.
You can usually feel the implant under your skin with your fingertips once it’s in place. It also contains a small amount of material that makes it visible on X-ray, so if there’s ever a question about its location, imaging can find it easily.
What Removal Looks Like
Removal is also a quick in-office procedure. Your provider numbs the area, makes a small incision, and slides the rod out. Removal costs range from $0 to $300, depending on your insurance. If you want to continue using the implant, a new one can be placed in the same visit.
Bleeding Pattern Changes
The most common side effect is a change in your menstrual bleeding pattern, and this is the number one reason people decide to have the implant removed early. A pooled analysis of 11 clinical trials found that among implant users:
- 22% stopped getting periods entirely
- 34% had only infrequent spotting
- 18% experienced prolonged bleeding episodes
- 7% had more frequent bleeding than before
There’s no reliable way to predict which pattern you’ll fall into beforehand. For more than half of users, bleeding decreases or disappears altogether. But for roughly one in four, bleeding becomes longer or more frequent, which can be frustrating. These changes are most unpredictable in the first six to twelve months and often settle into a more stable pattern over time.
Who Shouldn’t Use the Implant
The implant isn’t appropriate for everyone. Conditions that may rule it out include a history of serious blood clots, heart attack, or stroke; liver tumors or liver disease; a history of breast cancer or suspected breast cancer; and unexplained vaginal bleeding that hasn’t been evaluated. If you’re allergic to local anesthetics or antiseptics, insertion and removal could also be problematic since both are used during the procedure.
Certain medications can lower the hormone levels in your blood enough to reduce the implant’s effectiveness. These include some seizure medications, certain HIV treatments, some sedatives, and the herbal supplement St. John’s wort. If you take any of these, a non-hormonal method or one that isn’t affected by these interactions may be a better fit.
Fertility After Removal
One of the implant’s advantages is how quickly fertility returns once it’s removed. A study analyzing data from nearly 18,000 women found that those who had used implants or IUDs conceived the fastest, waiting an average of just two menstrual cycles. That’s faster than the pill or ring (three cycles), the patch (four cycles), or hormonal shots (five to eight cycles). The implant does not have any lasting effect on your ability to get pregnant.
Cost
The total cost of the implant, including the device and the insertion visit, ranges from $0 to $2,300. Most private insurance plans and Medicaid cover it fully under the Affordable Care Act’s contraceptive coverage mandate, bringing the out-of-pocket cost to zero. Without insurance, the upfront price is steep, but spread over three years it often works out cheaper per month than pills, patches, or rings. Clinics like Planned Parenthood and community health centers may offer sliding-scale pricing if you’re uninsured or underinsured.