CGMs, Help! compare

I was DXd as Type 2 about 10 years ago and have been insulin dependent for about 5 years. I am totally fed up with 6 to 8 finger sticks a day and am very interested in CGMs. Have been on Medicare for 10 years.
I need advice.

Both Dexcom and Freestyle Libre are now covered by Medicare. My limited research indicates that both work pretty well, but that Freestyle is simpler, less invasive, easier to use and does not require nearly as many finger sticks to keep calibrated.

I would appreciate any advice form those who have experience with CGMs as to which is better.

I have a doc’s appointment on Jan 29 and hope to have it taken care of then.
Thanks in advance for any help you can give.
Denver, CO

FYI - There are many reports on these forums of people actually getting Dexcom systems through Medicare. This is done direct through the Dexcom company - ie, NOT 3rd party distributors AFAIK.

I would be quite interested to hear a verified report of anybody getting a Freestyle Libre through Medicare.

I’ve been using a Dexcom, and now Medtronic Guardian 3 CGM for about 5 years. From what I’ve read, the Freestyle only gives a reading when you pass a “wand” device over it. This is not the same as a continuous glucose monitor, which is sampling every 5 minutes and outputting a graph that shows, not just where your BG is at a given moment, but which way it’s trending. Hence the term “Flash Glucose Monitoring” (FGM) being used to describe the Libre, as opposed to CGM. To my mind, this means the Libre is closer to a standard meter in that it gives you a snapshot rather than a dynamic picture of what your BG is doing. In practice, a true CGM makes it a lot easier and safer to do things like aggressive pre-bolusing to prevent spikes, and because it’s sampling all the time it can warn you when you’re drifting low or high. That’s going to be harder to do with an FGM unless you’re wanding the thing all the time (good luck with that overnight). But it definitely seems like a step up from fingersticking, and I gather they’re cheaper, smaller, and require less fuss to run.

Happy to stand corrected, but as far as I can tell, you could maybe get the same effect by just wanding the thing every 5 minutes

I have the Freestyle Libre and I love it . It’s very affordable, accurate and it does give you a graph with trending arrows like the Dexcom. The only thing it doesn’t do is give you alarms and since I’m aware of hypos I don’t have a lot of use for that feature ( the reason it doesn’t give alarms is because it doesn’t have a bluetooth chip) but you can buy an add on device called the Nightrider for about $100 that will make it into a full CGM with alarms. I do scan it frequently and I don’t find it a hassle. One of the things to be aware of about the Libre is it isn’t accurate for the fist 24 hours it’s inserted into your arm ( from what I understand Dexcom has the same issue) so make sure to insert it and just let it sit there without activating it for about 12 hours so that you don’t waste any of the 10 days waiting for it to acclimate to your body. I hardly ever prick my fingers anymore probably only once every 2 days.
It does however have 1 big con and that is the 12 hour warmup after you’ve started the sensor. I haven’t figured out a practical way around that yet but I am doing some research.


As of Jan. 2018:

Thanks for the correction regarding graphing trends. I’m curious about the 12-hr warmup. Does it not give you any data for that long, or is it just that you have to take what it tells you with the proverbial grain of salt? Dexcom and Guardian both warn that the first 24 hours can be unreliable, but they’re still useable in that period. Personally, the only times I’ve seen erratic readings in that period were when I’d hit a blood vessel inserting the sensor.

I’ve been using the Dexcom systems since 2009. I would not willingly choose to live without it. I find it invaluable in helping me to time meals, insulin doses, and carb corrections. I live alone. Dexcom’s ability to independently speak up at any time of the day or night is an endearing feature. But it can also be a nuisance and you do have to defend against alarm fatigue.

While I have not worn the Freestyle Libre, I’ve read many comments online. I think it’s way better than finger-sticking, when accurate. I think the Libre is like Amazon’s personal electronic assistant, Alexa. She will not speak unless you make a request. That is both good and bad. On the good side, you will not suffer any alarm fatigue, as Libre raises no alarms. On the bad side, Libre will hold its tongue while you crash into a hypo mess.

If money is the determinative factor with you, then I’d go with the Libre. If you can afford it, I would recommend the Dexcom. Dexcom allows customizing almost all the alerts and warnings so you can manage or prevent alarm fatigue.

Both of these devices will teach you, if you pay attention, how your glucose metabolism works. This is a huge benefit as you can learn all the tactics to not only make yourself healthier but also safer. In any case, if you make a poor choice for yourself now, you can always get the other system later. Sometimes you just have to try it to know what you can live with. Good luck!


Tim 35, Here are the Medicare requirements, re the Freestyle Libre.

Thanks for the info!

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No data for 12 hours which is why it’s such a hassle, like I said I’m looking into it. The European Libres only have a 1 hour warmup but I think since it’s not accurate for awhile the FDA or someone in the company decided not to trust us Americans to be able to figure out a way around that for ourselves.

Just as FYI, I have read quite a bit about this however the source documents go back to Abbott.

Perhaps call me skeptical, but until I see an announcement from CMS and/or verified reports from people who are actually getting the Freestyle Libre system through Medicare than I take this all with a grain of salt.

It is just who I am. I doubt everything. No disrespect intended.

I have been using the European Libres for over a year now. I have never had bad readings after the 1 hour warm up. I bolus using it and have had great control. I really love how easy it is to use. I am a bit hesitant to switch to the US version with it’s longer warm up and 10 day use vs 14 days.

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Hi Richard- I can only give you my experience & my thoughts. Please keep in my what I like and need may not be what you want and need.
First type 1for 47 years, MDI for about 20 years taking 5 injections a day before switching to a pump 27 years ago. I used a Medtronic/ MiniMed CGM on and off for a few years but just hated it. Switched to Dexcom about 5 years ago. Main reason was knowledge during the times I wasn’t testing and I have hypo unawareness. I love my Dexcom especially due to alarms for lows and highs. They help me stay in range. Testing was never an issue for me. After all those years of urine testing, blood sugar testing was the answer I needed. Before Dexcom it was 8-12 a day ( more if driving) so that was never a driving force for me. With Dexcom, I still test about 6 times a day. It is not as accurate as many people get but I love my alarms and trend arrows.
I did a clinical trial for the Libre a few years ago. The sensor you wear if a lot smaller than the Dexcom. And keep in mind it was a trial so I didn’t get any info from it. But it was easy to swipe the meter over the sensor.
It really comes down to what you are looking for. I suggest going to both websites and check out the many YouTube videos about both product. Have your questions ready when you see your doctor and together you can make a decision on which would work best for you. Good luck and I have found knowledge is power!

As someone who has had Type 1 for over 41 years, I would choose Dexcom over the Libre every time because I am hypo unaware and depend on the alerts. The alerts drive me crazy at times but they have been life-changing because I get alerted before I get incapacitated.

If I had Type 2 and was just wanting to avoid fingersticks while learning a lot about how my blood sugar reacts to food and life, I would choose the Libre. It is easier and wouldn’t bug me when I didn’t want information.


Some people are like that. actually, I’m a bit like that myself. But I have no reason to doubt the reports. I will find out soon enough.

I certainly understand your position. I just think it would be easier for me to manage my glucose level by checking it 30 or forty times a day by “wanding” the whatchacallit, than a finger stick 6 or 7 times a day.


Certainly I wish you the best in whatever choice you make.

Excellent advice all the way around. Thanks.

I have been using dexcom for over 10 years. This week I started a free trial of Libre sensor while using dexcom at same time. Alarms are important for me, so will likely stay with Dexcom, but there are some nice things about Libre.

Here is link to my comments and others related to Libre.


Thanks for the help everyone. I really appreciate it.