Continuous Glucose Monitor

Not sure how many of you have tried a CGM, got my doctor to prescribe a FreeStyle Libre 2. I just installed it and will post my results on Rapa day and others. Definitely feel like a lab rat :slight_smile:


The freestyle libre is pretty inaccurate, so my friend who is diabetic and gives me some of his extra sensors has told me to get a device like this below to check in the morning how far the Libre is off - so you know what is really going on. You can’t adjust/calibrate the Libre 2 directly. In my experience the Libre is typically 15 to 30 points higher than the finger prick glucose measure.


Thank you @RapAdmin. I may do some backup testing. I have a good friend who has a daughter with type 1 she uses the Dexacom g6 as her daily driver but has used the Libre 2 before and found it okay. He suggested I use it for value and since I am only looking for directional readings. I am not taking insulin after all.

I have taken a few ratings thus far. 101, 92, 106. All pretty low.

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I have tried the Dexcom G6 and more recently the G7. The G7 did fall off, but Dexcom sent another. I will run a Dexcom session again soon, but I want to plan things around that.

generally carb tolerance goes way down on rapa days

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Interesting drop post Rapa and exercise to 60s. Fun to watch this.


One important thing to know about the Libre2: the current “reading” and trend line for the last 20 minutes is a model. It takes 20 minutes for the sensor to finalize a reading, so when your glucose is changing, I find it tends to over shoot.

You’ll notice that the next time you go to scan the last 20 minutes of the previous scan will be gone.

I also highly recommend upgrading to the Libre3, as it does not require scanning. It streams to the phone and is smaller.

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Is that something you have personally experienced by measuring it?

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yes, when wearing a monitor, I saw much larger then normal spikes in the 48 hours post rapa (7 mg at the time of rapamune)

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Interesting. Thanks for the info.

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Interesting research… suggesting that supplements may impact the readings on your blood glucose monitor and make them inaccurate…

Glucose meter users should be alerted that some of these devices might produce spurious glucose results not only in patients on vitamin C therapy but also in those being administered other antioxidants. As discussed herein, the clinical relevance of the data is immediate in view of the current use of antioxidant therapies for disorders such as the metabolic syndrome, diabetes, cardiovascular diseases, and coronavirus disease 2019.


Can anyone recommend a good place to buy a CGM? I’d like to buy one, but here in Hong Kong they really overcharge. I can have it shipped to the USA and pick it up during my travels. Thanks.

Can you not just order Dexcom online?

Here in the states you need a prescription from a Dr to get a CGM. Mine had no issue prescribing but made a point to indicate it wasn’t for a health issue so insurance wouldn’t help pay for it. We can debate proactive versus reactive costs but that is the current policy. At least for BCBS one of the largest US private insurers.

Do you have a doctor in the US (or Dr. friend who can write a prescription)… Costco is probably the cheapest. But if you need to get a doctor and a prescription… perhaps agelessRX?

You need a prescription for a CGM? That’s ridiculous. Over here you can just buy one. If you want to monitor your own blood glucose, anyone is allowed to do it. Crazy.


In the UK you can just buy the CGM. If you want a state subsidised one you need a prescription, however. How much does dexcom cost in HK?

The trouble in USA is that manufacturers of expensive drugs or medical devices want them to require a prescription, otherwise most medical insurance in USA will not cover it. Sometimes they can create 2 types of product, one OTC and one by prescription only, but they have to be different for insurance to cover the prescription version, so this only works for drugs where the prescription version will have a high dose.

By law in USA, basic types of insulin must be available without a prescription, so patients can get them in a hurry, otherwise it is up to the manufacturer for patented drugs or medical devices to apply to the FDA to permit OTC sales (without prescription).

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The Dexcom G7 12 month intensive package costs just under $3,000 USD. That’s a bit much for a CGM IMHO.

Yes, but unless you are actually diabetic you don’t need it all the time. I bought 3 sessions last year and three sessions this year. A session lasts 10 days. In fact I have two sessions I have not used as yet. I plan when I want to run a session to see what happens in terms of inputs and outputs. I can assume that the pattern will otherwise remain the same.