Best Implantable CGM in 2026: Eversense E3 vs 365 Reviewed

Implantable continuous glucose monitors represent a fundamentally different approach to glucose sensing. Instead of an adhesive patch that must be replaced every 7 to 15 days, an implantable CGM uses a fluorescence-based sensor inserted under the skin by a healthcare provider during a brief in-office procedure. Senseonics is the sole manufacturer of implantable CGMs, producing the Eversense E3 (6-month sensor life) and the Eversense 365 (1-year sensor life). Both devices eliminate adhesive skin reactions, frequent sensor changes, and the insertion discomfort that some patients experience with patch-based systems.

The Eversense platform uses a proprietary fluorescence-based sensor technology that differs from the electrochemical glucose oxidase sensors used by Dexcom, Abbott, and Medtronic. The fluorescence approach measures glucose by detecting changes in light emission from a glucose-sensitive polymer coating, which does not consume glucose during measurement. This non-consumptive reaction contributes to the sensor longevity — up to 365 days for the Eversense 365. Both Eversense models feature on-body vibration alerts, a unique capability that notifies users of high and low glucose events directly through the transmitter worn on the arm, even when the smartphone is not nearby. The trade-offs include twice-daily fingerstick calibration, a 24-hour warmup period after implantation, and a higher upfront cost that must be amortized across the sensor lifecycle.

The Eversense 365 is the superior implantable CGM for patients committed to long-term implantable monitoring because it halves the number of insertion procedures (1 per year vs 2) and reduces the amortized daily cost. The Eversense E3 is the better choice for patients who want to trial the implantable format for a shorter 6-month commitment before committing to a full year.