Trying the Eversense implanted CGM

I am starting on an Eversense CGM today and will post occasional observations about this exciting new experience. The 90 day sensor was “implanted” yesterday. The first thing I learned is there is an initial 24 hour warmup, followed by a 6+ hour calibration (4 BG readings 2+ hours apart) in order to start using the CGM. Right now I am 1 hour into the calibrations.

An Eversense sales rep and trainer were present and seemed very knowledgeable. I have no hesitancy giving the whole insertion process a positive review. The only downside was the time commitment to go to the endo office (and pay) for the insertion.

Implanting the sensor (the Eversense people call it “insertion”) was a painless procedure involving an endo numbing my upper arm, making a smallish incision with a scalpel, and using a special tool to insert the sensor into my flesh through the incision. It was entirely painless and was patched up with Steri strips and Tegaderm. Unfortunately I am not a contortionist so was unable to get a photo of the bloody incision, etc. Here is the patched up arm about 6 hours later. After noticing the bleeding I added a large bandaid over the Tegaderm and played hockey for 2 hours last night, with no pain or issues.

Here is a picture of the transmitter installed over the implanted sensor. The signal is fine even with the extra gauze covering the sensor (Bandaid plus Tegaderm). The transmitter needs to be charged for roughly 15 minutes once daily, followed by carefully aligning it over the sensor using special Eversense double sided tape patches. The tape only needs to last 24 hours, and seems fine so far. I added a Grif Grip for peace of mind.

Initial impressions:

  1. After inserting the sensor, starting up the CGM requires about 1 1/2 days before you can use it as a CGM. Not a problem for me but still was a bit of a surprise.

  2. The transmitter is larger than a Dexcom G5 but more rounded off around the edges. Mine was placed on the backside of my upper arm and I doubt the size will bother me with it back there. However, I have to use a mirror for alignment, installing Grif Grip, etc. Alignment is aided by the app (which reports signal strength as you fine tune your placement before taping it down) but is sensitive enough where I would not want to try to rush it.

  3. The transmitter must be turned on to adjust the settings on the app. There are multiple settings available for alerts, etc. Notably, you will set your twice daily calibration times. (example 7 AM and 8PM). My understanding is the calibrations must occur within a window of the preset scheduled calibration time or …(? I can’t remember what they told me will happen if you miss a calibration window). It’s almost guaranteed that I will miss a calibration sooner or later, so I hope this will not be a major deal.

My overall impression is that I will need to relearn some of the habits I developed as a long time Dexcom G5 user. I was almost going on autopilot for the Dexcom insertion, taping, initial calibrations, Etc. These steps are all new and different for Eversense.


@John58 this is great! Really looking forward to your insights. I find this technology intriguing.


Eversense seems like a really interesting solution for anyone who might need to remove the device from their skin every now and then. With other technologies, you can’t just remove the sensor and reattach it later. How big is the implanted sensor? Would you say that it seems sensitive, or will it be able to take bit of a beating?

I’m looking forward to hearing about your experiences.

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Look forward to hearing all about it!

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Here is some info from their literature:

I am already regretting not having a view of the insertion…next time I will bring my own mirror. The literature has a picture of the sensor in somebody’s fingertips:


I played hockey last night with the sensor in my arm, freshly bandaged and did not feel any sensitivity. There is none of that pokey pain you sometimes will get with a G5 sensor that is inadvertently installed in a bad spot. The endo purposely felt around and found a nice soft zone towards the backside of my bicep. (Time to start lifting weights, ha). I am pretty confident that once the incision heals over it will be able to take a beating. According to the literature they install it pretty shallow beneath your skin (3-5mm).


Thanks for sharing @John58

I am very interested to hear your updates!

First update, morning of Day 3:
Sensor was installed Monday 4/1 mid morning. Day 1 was Monday, 24 hour warmup period with no BG data.
Day 2 was spent with 4 initial calibrations, minimum 2 hours apart. Tech support calls this “initialization”. I finished this by about 5:15, using lots of test strips to make sure they were good flatline-ish calibrations.

After the second initialization was entered, I started seeing BG values on the iPhone. These were too far off the Dexcom and fingersticks to pay attention to. My last (4th) initialization was at about 5:15 PM, and coincided with a G5 sensor restart (Day 7 of my G5 sensor, Day 104 of my G5 transmitter).

I partially knocked the transmitter off my arm bumping into a door jamb. The app includes a placement/alignment tool that is very easy to use (left handed in front of a mirror) to reset the transmitter with fresh special tape and a fresh Grifgrip. Abandoned the band aid, which seemed to contribute to the shaky attachment enabling the transmitter to break loose under a pretty mellow collision with a door jamb.

Initial use of the Eversense Day 2 evening and overnight did not correlate well with either the Dexcom or fingersticks. Jumpy values similar to the first day of a Dexcom sensor. I did not bother to plot those because they were all over the board. Tech support says this is to be expected while the sensor settles into the healing flesh at the insertion site.

Overnight: I tried out the vibratory alerts on my arm overnight. I enabled the “predicted low glucose alert” and left my iPhone in a different room, also used the G5 receiver at night for Dexcom. There were multiple alerts overnight that did not wake me up, I slept right through them. These alerts were caused by a 3AM low (Eversense BG 59, which G5 recorded as BG 96). I did not wake up to check with fingersticks, etc. and doubt that this was a valid BG reading.


Because the sensor is so much bigger, I would guess it could be 3-4 days before things “settle in” and the initial inflammation dies down, but should be good after that. So, from the info you have described, you still need to fingerstick at least twice a day, is that correct?

Btw - great writeups, thank you for sharing.


Is there a way to also get audible alerts on a phone?

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Chris, Yes, the Eversense requires 2 calibrations per day. Between those and the extra strips used to double check CGM values I figure I’ll use a few more daily than I had on G5. G5 allows skipping calibrations but Eversense will not allow skipping any. In fact, the calibrations are “pre scheduled” within a 3 hour window using the app. I will surely miss one of those windows some day and will see what happens!

So far so good this morning, getting some BG data that seems more reliable.


Aaron, Yes the iPhone will make noise alerts if within range of transmitter (range seems pretty good, mfr quotes about 25 feet). There also is a ping on my Apple watch for alerts. I might try those at night after my G5 transmitter dies. My preference is vibratory because my wife is a light sleeper. Maybe I can acclimate myself to the vibration and learn to wake up for those? Time will tell.


Sheesh this is getting mind boggling! The Dexcom and Eversense seem to be tracking general trends OK but Eversense is definitely a lot slower to recognize a rising BG. Guessing my Day 3 sensor is still acclimating…

15 min after the pictures were taken Contour Next says 105, Dexcom says 87 and level, Eversense says 81 straight up.


I was expecting the Eversense to have much better results.

How is the insertion site? does there seem to be unusual pain or tenderness? I am wondering if there could be inflammation or infection or anything like that which is impacting the readings?


I am thinking around the same lines here - For me, a a Dexcom G5 insertion where there is lots of blood takes a lot longer for the readings to stabilize than for a clean insertion.

So I am wondering if the trauma of the insertion needs to heal before the readings will stabilize.

@John58 - thanks for the screen captures on the eversense App

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The insertion site feels fine and does not seem to be infected. And Eversense seems to eventually catch up to a straightline…it’s just lagging behind fingersticks by longer than I expected.

I am thinking along those lines too. With a rise or fall in BG, I’m seeing a pattern of a longer lag time for Eversense readings compared to typical Dexcom lag time and it seems too early to say if that pattern will continue. A half hour before that screen shot I was reading 59 on the Contour Next and 79 straightline on the Eversense…which then trended lower for about 30 minutes after Dexcom says I started climbing back out of the low.

I’ll assess the accuracy for another week before I panic if it does not improve. One of the tech support people told me he’s heard of 10 days max from some users for the sensor to acclimate.


10 days is a long time to wait for stability, though I suppose it might be worth it if it’s followed by 80 days of reliable values with no sensor change.

Apparently there’s a version called Eversense XL that is supposed to last 180 days, which would mean sensor changes only twice a year. It’s available in Sweden, but I don’t know anyone using it. Maybe you can get an upgrade when it’s approved by the FDA :slight_smile:


My understanding is everybody using the Eversense in Europe has now been upgraded to the XL such that there are no remaining active users of the 90-day version in Europe.

The 180-day version is undergoing a clinical study in the USA which is required for the FDA submission. I think it is the intention of Senseonics management to submit the 180-day device (XL) for approval to the FDA towards the end of this year.


This is kind of blowing my mind :exploding_head: I wonder if there’s variability in sensor accuracy depending on each sensor. Like if one of my dexcom sensors is way off, o well, at least it’ll get replaced in a few days… but if one of the eversense XLs is off…


Good point. I suppose that might be one reason to have the twice a day calibration requirement. It would probably be pretty hard to create a factory-calibrated 180 day sensor.