Libre 2 Initial Thoughts

First and foremost, I haven’t started using my Libre 2 sensors, yet. I’m using up the last of my Dexcom G6 sensors (2 left, plus the one on my leg now, as of this post). I’ve been working on figuring out how best to transition to the Libre 2 while receiving as equivalent experience as possible.

As I noted in my previous post , getting the data is going to be a bit of a problem. Abbott, makers of the Freestyle Libre systems, seems to work against users who want to manage their diabetes on their own terms, putting a lot of effort to keep their users within their software and data ecosystem. This differs from Dexcom, which provided a way to share the data to other apps and services. This data sharing is how I was able to use an app called Sugarmate to manage my diabetes, and to share the data to my Home Assistant Dexcom integration, and ultimately log the data into InfluxDB from there. There’s no such data share on the Libre side of things.

But motivated people get creative with solutions.

Sugarmate doesn’t support Libre sensors of any version. It supports getting data from Dexcom or Nightscout. There are Nightscout uploaders for Libre sensors, but using them on iOS is a pain and requires a lot of work to maintain, which goes completely against my goals in all of this. It’s the same reason I won’t be using xdrip4ios or Diabox.

There’s a few apps that do support the Libre sensors in the app store. There’s Tomato, which is built to be used with miaomiao transmitters, then there’s Diabeto, and then there’s Shuggah. From what I can tell, the version of Tomato in the app store is very old and has features gated behind a subscription that the app won’t let you set up because it’s broken. Diabeto just has a really terrible UI/UX. I tried using it for a bit and just got frustrated with it.

Shuggah looks to be the closest I can get to what I want. Reportedly, it’s a fork of xdrip4ios, though their Dexcom support is broken so I couldn’t immediately switch to it. Shuggah supports Libre 2 sensors in 2 ways: Direct scan (so that it functions like the Libre apps) and through transmitter devices like miaomiao.

Let’s touch on that for a moment. I’ve mentioned miaomiao twice, now, so what is it?

Dexcom works as a 2 piece system, where there’s a sensor and a transmitter. The sensors are actually super simple devices with no electronics, as the electronics are entirely in the transmitter. Essentially, the sensor is just the filament probe and a way to hold it in place, as well as carry the transmitter and keep it connected to the probe.

Libre, Libre 14 day, and Libre 2, on the other hand, only have a sensor that acts as a transmitter, but not in a constant fashion like Dexcom, requiring NFC scans to get readings. This tends to get referred to as a “flash” CGM, or I’ve even seen it called a FGM (flash glucose monitor). It does continuously monitor your glucose, though. It also has bluetooth. But it only uses bluetooth to communicate highs and lows that need action. So it doesn’t maintain communication with your reading device. Attempting to do so would apparently cause the battery to fail before the rated 14 days of usage.

A handful of companies developed addon transmitters for Libre sensors. They handle the bluetooth side of things and read from the sensor via NFC. They attach to the outside of the sensor so that they can read it. Supposedly, because they use NFC to read the data from the sensor, they don’t drain the battery excessively.

The sensors are already bigger than the Dexcom setup, so you can imagine these add to the bulk. It’s not ideal.

Dexcom transmitters last about 90 days or so. They’re not rechargeable. Once it’s done, you toss it. These addon Libre transmitters are rechargeable.

I went with miaomiao because it seems to be well regarded, though the Tomato app is a problem, as I mentioend. But other apps can use it. I chose it because it has the charging contacts on the top of the device rather than the under side. All of these devices need recharging about every 2 weeks so if the battery drains too much with the contacts underneath, that means it has to come off to recharge. The miaomiao, on the other hand, can be recharged while still attached to me.

So while Abbott would prefer you use their app to manage what they probably consider to be their data (really, it should be your data), there’s ways around that.

As I mentioned at the start, I haven’t made the switch yet. I’ve settled on using miaomiao with Shuggah, but I still don’t know how it all works together yet. I haven’t received my miaomiao device yet so I’m still waiting on that and will get all the instructions going once I’m able to.

Unfortunately, the future looks bleak. Dexcom G7 and Freestyle Libre 3 are due to release this year and you might think that’s a good thing. They’re very similar devices. Libre 3 becomes a fully capable CGM, as in it now maintains a connection with the reading device similar to Dexcom.

The problem comes in that getting the data may become impossible. Well, at least for a while. Sugarmate didn’t read data from the Dexcom transmitter. It got the data from Dexcom as part of an API for data sharing. Abbott provides no such capabilities. I could, potentially, be stuck using the Libre 3 app.

You might suggest maybe going back to Dexcom with the G7 since they are simplifying the system. Both companies have stated the price of their next generation systems will not change. My suspicion is Dexcom G7, as a system, may be cheaper than G6, as a system, but from what info I can find, it’s still only approved for use for 10 days, not the 14 days the Libre system is rated for, and not the 15 days they have applied for. At retail price, Libre 2, and likely Libre 3 sensors are around $120 each, with various places pricing around $78, and with discounts, $75 for 2 sensors. Dexcom G6 sensors are around $160-180 each, with some discounts bringing them closer to $100 each. I would expect G7 sensors to also be around that price, but no longer needing to buy a separate $300 transmitter every few months. So the per sensor cost is still higher than Libre. However, per month, you’d need 3 G7 sensors versus Libre 3’s 2 sensors.

So I’m still priced out of the Dexcom G7. I’d rather deal with the data walled garden than spend 3-4 times the cost.

I really like Dexcom, but they need to work on their cost. With insurance companies changing policies on covering CGMs, making it so much harder to get approved, people are going to migrate to their competition. Exactly as I’m doing now. Abbott wins and has no motivation to change their data policy.