Glysens

Last Updated on October 15, 2025

GlySens is pursuing a fully implanted continuous glucose monitor (CGM) that eliminates the day-to-day hassles of adhesive by placing the sensor completely under the skin. Early feasibility studies are underway, but the system is not yet FDA-cleared. For an implantable option available today, see Senseonics’ Eversense implantable CGMs (six-month E3 and one-year 365).

What is GlySens, and why does a fully implanted CGM matter?

GlySens is a San Diego–based developer working on the Eclipse ICGM, a CGM designed to live entirely under the skin and transmit glucose data without any on-skin transmitter. The concept aims to reduce adhesive issues, accidental knock-offs, and frequent sensor swaps associated with short-wear CGMs. Company and third-party summaries describe a long-duration goal (multi-month to longer) and smartphone connectivity.

What evidence exists for GlySens today?

An ANZCTR-listed feasibility study of the third-generation Eclipse-3 design evaluates tolerance, safety, wound healing, and sensor performance in a small cohort, noting a ~40% smaller sensor versus prior versions and a planned implant period of roughly 4.5–8 months. These are early, investigational data—no U.S. marketing clearance has been announced.

Peer-review and review-style summaries also place GlySens within the broader field of implantable glucose sensing, contrasting entirely with subcutaneous approaches and systems that require an external transmitter.

How does GlySens compare with Eversense implantable CGMs?

For people who want an implantable option today, Senseonics’ Eversense systems are commercially available in the U.S. The Eversense 365 received FDA clearance on September 17, 2024, as an iCGM with up to one-year wear and a reduced calibration schedule; the six-month Eversense E3 previously demonstrated sustained accuracy in the 180-day PROMISE study. For features, insertion, and practical details, see our Eversense page.

• Wear time: Eversense offers 12 months (365) or 6 months (E3) today; GlySens targets multi-month wear but remains in feasibility.
• On-body experience: Eversense requires a small skin-worn transmitter over the implanted sensor; GlySens’ design goal removes on-skin components.
• Calibration: Eversense 365 moves to weekly calibration after initialization; E3 typically uses daily calibration after day 21. GlySens calibration details for any marketed product are not yet established.
• Accuracy: E3 accuracy in PROMISE reported MARD in the high 8% range; 365 inherits the platform with labeling that supports iCGM pathways. GlySens has not published or marketed performance claims.
• Regulatory status: Eversense systems are FDA-cleared; GlySens is investigational with feasibility listings and no FDA clearance to date.

What do major guidelines say about CGM use?

The ADA’s 2025 Standards of Care (Diabetes Technology) recommend CGM for most insulin-treated individuals and support broader, earlier CGM adoption. The 2025 updates also emphasize consistent reporting across CGM and connected devices, which will matter as new implantable systems evolve.

Who might consider an implantable CGM—and what should they ask?

If the idea of fewer adhesive issues, a longer-wear sensor, and vibration alerts appeals to you, explore the currently available Eversense systems while GlySens advances through studies. Discuss with your clinician:

• Insertion/removal workflows and clinic availability (Eversense is placed and removed in-office).
• Calibration frequency and early-phase requirements (e.g., weekly after initialization for Eversense 365).
• Insurance coverage, Medicare considerations, and data-sharing for care teams.

Key takeaways

• GlySens is developing a fully implanted, no-on-skin CGM with multi-month wear goals—currently in feasibility studies.
• Eversense is the only implantable CGM available today in the U.S.: 6-month E3 and 1-year 365 (iCGM) with reduced calibration.
• Guidelines support CGM broadly for insulin-treated individuals; device choice should consider insertion logistics, calibration, and coverage.

Explore Eversense details

For indications, insertion, calibration, and accuracy data, visit our dedicated page: Eversense Implantable CGMs.

References (selected)

1. Garg SK, et al. PROMISE study—accuracy and safety of a 180-day implantable CGM. PubMed; full text.
2. Senseonics. Eversense 365 FDA clearance (iCGM).
3. FDA 510(k) K241335. Eversense 365 App—weekly calibration details.
4. ANZCTR. Eclipse-3 feasibility trial.
5. ADA. 2025 Diabetes Technology—Standards of Care.

Other Resources (high-authority outbound links)

• ADA Standards of Care portal (overview and updates).
• Senseonics press release—Eversense 365 iCGM.
• FDA 510(k) summary—Eversense 365 App.
• ANZCTR—Eclipse-3 feasibility.
• PROMISE study full text (Eversense E3 accuracy).

Editor’s note: This page will be updated as peer-reviewed results and regulatory milestones for GlySens become available.