Nexplanon remains highly effective beyond its 3-year FDA-approved lifespan. In the largest study to date on extended use, over 200 women used the etonogestrel implant for a full 5 years, and zero pregnancies occurred during years 4 and 5. The hormone levels that prevent pregnancy decline gradually but stay well above the threshold needed to block ovulation for most users through year 5.
What the Research Shows for Years 4 and 5
The FDA approved Nexplanon for 3 years of use, but clinical evidence tells a more complete story. A large, geographically diverse study followed women who kept their implants in place for up to 5 years. The implant showed 100% efficacy in years 4 and 5, with no pregnancies recorded during that extended period. Over the full 5 years, the cumulative pregnancy rate was just 0.6 per 100 women, a number statistically equivalent to the 5-year levonorgestrel implant (Jadelle) that was already approved for that longer duration.
These findings aren’t from a single small trial. Researchers specifically noted that this study had the highest number of participants completing at least 5 years of use compared to previous efforts, and the results lined up with earlier evidence showing strong efficacy through year 4.
Why It Still Works: Hormone Levels Over Time
Nexplanon prevents pregnancy primarily by releasing a steady stream of a synthetic hormone (etonogestrel) that suppresses ovulation. The key question for extended use is whether enough hormone remains in the rod to keep doing its job. The answer, based on blood-level measurements, is yes for the vast majority of users.
The minimum blood concentration needed to reliably suppress ovulation is about 90 pg/mL. At year 3, the median level in users was 207.7 pg/mL, more than double the threshold. At year 4, it was 166.1 pg/mL. At year 5, it was still 153.0 pg/mL. So while hormone release does taper over time, the median user at year 5 still has nearly 70% more hormone circulating than the minimum required.
That said, there’s a range. Some individual measurements dipped below 90 pg/mL at years 3 and 4 (the lowest recorded was 63.8 pg/mL at year 3 and 25.0 pg/mL at year 4). This means a small number of users may have reduced protection, even though no pregnancies were observed in the study population. Ultrasound studies have detected occasional ovulation in implant users starting around 30 months, though ovulation alone doesn’t guarantee pregnancy since the implant also thickens cervical mucus and thins the uterine lining.
Does Body Weight Affect Extended Efficacy?
This is a reasonable concern, since a higher body mass could theoretically dilute the hormone’s effect as levels decline. Pharmacokinetic studies have found numerically lower hormone concentrations in women with a BMI of 30 or above. However, a systematic review of the available evidence concluded that the implant’s effectiveness in women with overweight and obesity “falls within the range of published data across all implant users regardless of weight status.” In other words, no study has demonstrated that higher BMI actually reduces the implant’s real-world pregnancy prevention during the approved 3-year window.
For extended use specifically, one study reported a Pearl Index (the standard measure of contraceptive failure rate) of 0 per 100 woman-years at both year 4 and year 5. Blood measurements also confirmed that median hormone levels stayed above the 90 pg/mL ovulation threshold across all BMI categories. Still, data on extended use in higher-weight individuals is limited, and this is an area where the evidence is thinnest.
FDA Labeling vs. Clinical Evidence
The 3-year label on Nexplanon reflects what the manufacturer submitted to the FDA for approval, not a hard cutoff where the device stops working. Regulatory approval requires specific clinical trial data, and the original trials were designed around 3 years. Extending the label requires additional regulatory submissions, which is a commercial and bureaucratic process as much as a scientific one.
The clinical data supporting 5-year use is strong enough that researchers have explicitly stated the findings “provide valuable information for policy makers, family planning programmers and clinicians that the ENG-releasing subdermal implant is still highly effective up to 5 years after insertion.” Some clinicians and reproductive health organizations already incorporate this evidence into their guidance, though your provider may still follow the FDA label.
What This Means If Your Implant Is Expiring
If you’re approaching or have passed the 3-year mark, you’re not suddenly unprotected. The transition from “highly effective” to “less effective” is gradual, not a cliff. The hormone doesn’t run out on day 1,096. Based on current evidence, the implant continues to provide strong contraceptive protection through at least year 4, and likely through year 5 for most users.
If you want to keep using an implant and your current one is past 3 years, the replacement procedure is straightforward. The single-rod design of Nexplanon allows removal in about a minute on average. A new implant can typically be inserted during the same visit. If you’re considering keeping your current implant beyond 3 years, that’s a conversation worth having with your provider, armed with the knowledge that the evidence for extended use is considerably more reassuring than the label alone might suggest.