Editor’s Note: On June 21, 2018, the FDA announced the approval of the implantable EverSense CGM device. Read the statement here.



The Eversense Continuous Glucose Monitoring (CGM) system feels like something out of the future.

You have a tiny sensor under the skin in your arm that broadcasts your glucose levels in real-time. You get an accurate reading without the hassle of inserting sensors into your skin every week. No more skin rashes, no more site changes. Just easy access to the information that you want.

Eversense is currently available in Europe and awaiting approval in the USA. Below is a look at the current technology, availability, pricing and the development plans.

How Does Eversense Work?

Eversense is an implantable sensor about the size of a headphone connector. The sensor has a membrane that absorbs glucose and a little blue LED light. By measuring how much light passes through the membrane, it can tell your glucose levels.

In studies, the sensor is as accurate as Dexcom G5 and more accurate than Medtronic Enlite and FreesStyle Libre Pro sensors. Its MARD, a measure of accuracy, is 8.8% compared to 9%, 9.6% and 12% respectively for the others.

The sensor itself is contains no battery. It gets its power wirelessly from a small transmitter that you tape to your skin. It uses the same near-field communication (NFC) technology that powers and communicates with credit card chips.

Implanting the Sensor

The procedure to insert is similar to that used for the birth control implant or the upcoming Intarcia micropump. The health care provider numbs the skin, makes a tiny incision (about 8-10mm), and uses a special tool to insert the sensor directly under the skin. The skin is taped up and heals quickly. The whole procedure just takes a few minutes. Even as someone with no medical training, I was able to successfully insert and remove a sensor on a dummy on the first try.

During the first day, the sensor is getting calibrated and is not usable. Starting on day two, you can calibrate it by taking four blood sugars at least two hours apart and entering them into the system. Going forward, it requires two calibrations every day.

The removal procedure is basically the same. You make a tiny incision and it pops out. Tape up the incision and you are ready to go.

The Transmitter

I wore a transmitter for an afternoon and was struck by how comfortable it is. All of the other technology on the market uses acrylic adhesives that are strong but can cause skin irritation. Their adhesive is made from non-allergenic silicone because it only needs to last a single day. (The adhesive doesn’t need to hold a sensor on for an entire week or more, so it doesn’t need to be as aggressive.).

You can easily remove the Eversense transmitter without pulling out your hair (very convenient for a guy!). Because the sensor is implanted, you don’t waste one when you remove the transmitter. Though it’s not approved for reuse, I found it easy to put the transmitter back on with the same sticker. So is seems that you can remove it for a shower and put it right back on.

The battery on the transmitter is rechargeable and recharges in about 15 minutes. It last for 36 hours on a single charge.

The transmitter gets real-time sensor readings and transfers them to your phone by Bluetooth.

The sensor itself is able to vibrate to give alarms. Those that have slept through a continuous glucose meter alarm will appreciate how nice it is for the transmitter taped to your skin to vibrate. No more sleeping through lows.

The App

You access your glucose data through an iOS or Android app. You can send your health care provider a copy of your glucose data in a few taps.

The app shows you your current sensor reading and whether you are trending up or down:

It allows you to track when you eat meals, take insulin, exercise or take other actions:

It has a simple summary chart that lets you see how you have been doing in the last day, week, month or quarter:

Pricing & Availability

The Eversense CGM System is Europe, including: Sweden, Germany, Norway, Italy, Netherlands, Austria, Belgium, Switzerland, Spain, Finland, South Africa, Denmark, and Poland. They submitted the product to the FDA for Pre-Market Approval in October 2016 and anticipate approval in 2018.

Senseonics is planning on pricing the 90-day sensor competitively with Dexcom and Medtronic (about $7-$8 per day) All three of these systems are more expensive than the FreeStyle Libre (about $4-5 per day) which does not have a wearable transmitter and cannot do real-time alerts.

Recently, Senseonics received CE mark for the 180-day extended life sensor called Eversense XL. That twice-a-year sensor has now been introduced in the UK and they anticipate introducing to rest of Europe in 2018. As Senseonics moves to 180-day sensors and beyond, the price will drop significantly, according to CEO Tim Goodnow. A single sensor will last twice as long while the cost of building and implanting it stays the same. This will enable them to eventually compete against the FreeStyle Libre on price per day.

Long-Term Plans

Senseonics is working on continuously improving the life of the sensor. Their goal is to eventually have it last a full year. At the same time, they are working on removing the need to wear a transmitter. Instead, you could wave your phone over the sensor and quickly get a reading.

Want to Try It?

Would you try an implantable sensor? Let us know what you think in the comments!

Read more about Android, continuous glucose monitor (CGM), Dexcom, eversense, exercise, freestyle, insulin, Intensive management, iOS, libre, mean absolute relative difference (MARD), Medtronic, sensenoics, Senseonics, U.S. Food & Drug Administration (FDA).