Nexplanon is FDA-approved to prevent pregnancy for up to five years, and the labeling states it must be removed no later than the end of that fifth year. If you keep it in longer, two things change: the hormone level drops low enough that pregnancy becomes possible, and the implant can become harder to remove as tissue grows around it. Neither of these changes happens overnight, but both are worth understanding if your implant is approaching or past its expiration.
How the Hormone Level Drops Over Time
Nexplanon works by steadily releasing a synthetic hormone called etonogestrel into your bloodstream. That release isn’t constant. In the first several weeks after insertion, the implant puts out 60 to 75 micrograms per day. By the end of the first year, that drops to roughly 40 to 50 micrograms per day. By the end of year five, it’s down to about 15 to 20 micrograms per day.
This declining curve is what sets the clock on the implant’s usefulness. The hormone works primarily by stopping ovulation, and as the daily dose shrinks, your body gets closer and closer to resuming its normal cycle. Once the implant passes its approved lifespan, hormone output continues to taper, and at some point it simply isn’t releasing enough to reliably prevent pregnancy.
Pregnancy Risk Beyond Five Years
The reassuring news is that the transition from “protected” to “unprotected” isn’t a sharp cliff. A large study tracking implant users beyond the labeled duration found zero pregnancies among 223 women who used their implants into the fourth year and zero pregnancies among 102 women who continued into the fifth year, published in Global Health: Science and Practice. At the five-year mark, the cumulative pregnancy rate was just 0.6 per 100 users.
But those numbers come from a study population, not a guarantee for any individual. The hormone threshold needed to suppress ovulation varies from person to person. One commonly cited figure is a blood concentration of 90 picograms per milliliter, but more recent laboratory analysis found that over half of implant users ovulated even when their levels were above that number. In other words, the “safe” hormone level isn’t as predictable as researchers once thought. The further you go past year five, the less certainty anyone can offer about whether your implant is still working.
Changes to Your Period and Symptoms
Many people notice their bleeding patterns shift as the implant ages. In the first couple of years, irregular spotting or absent periods are common because hormone levels are high enough to keep the uterine lining thin. As etonogestrel output decreases, your body’s own hormonal cycle starts to reassert itself. You may notice more regular monthly bleeding, heavier periods, or a return of symptoms like cramping and breast tenderness that you hadn’t experienced while the implant was at full strength.
These changes can actually serve as a signal. If you’ve had years of light or absent periods on Nexplanon and suddenly start bleeding more regularly, that’s your body telling you ovulation may be resuming. It doesn’t mean you’re definitely unprotected, but it’s a practical heads-up that the implant’s hormonal effect is waning.
Why Removal Gets Harder Over Time
This is the risk people tend to overlook. The implant sits just under the skin of your upper arm, and over time your body forms a thin capsule of fibrous tissue around it. The longer the implant stays in place, the thicker and tougher that capsule can become. In straightforward cases, removal takes a few minutes with a small incision and local numbing. When fibrous tissue is dense, the procedure becomes more involved.
In some cases, the implant also migrates from its original position. One documented case involved a woman whose implant had been in place for four years. By the time she sought removal, the rod had shifted toward her armpit and was encased in a fibrotic capsule that required a 5-centimeter incision, general anesthesia, and a surgical team that included a vascular surgeon. That’s an extreme scenario, but it illustrates why waiting years past the recommended timeline adds a real, physical complication that has nothing to do with pregnancy risk.
Even without migration, a deeply encapsulated implant can be difficult to feel through the skin. If your provider can’t locate the rod by touch, imaging (usually ultrasound or, less commonly, an MRI) is needed before removal can be attempted. This turns what should be a quick office visit into a multi-step process.
What to Do if Yours Is Overdue
If your Nexplanon has been in longer than five years and you don’t want to become pregnant, use a backup method like condoms until you can get it replaced. There’s no emergency, but the sooner you schedule removal, the simpler the procedure is likely to be.
If you’re hoping to get pregnant, you can have the implant removed at any point. Fertility typically returns quickly once the rod is out, often within a few weeks, because the residual hormone levels at that stage are already quite low.
If you want to continue using an implant, your provider can remove the old one and insert a new one during the same visit. The new implant starts working immediately when placed on the same day, so there’s no gap in protection. The key is not to treat the five-year mark as a suggestion. The implant doesn’t become dangerous if left in place a few months past its date, but every additional month increases both the pregnancy risk and the chance that removal will be more complicated than it needs to be.