I had Libre 2 for 12+ months from Feb '21. Over 50% failed within the 14 day period; none fell off. Some read consistently very high, some consistently very low, some started high and became very low. Some just stopped. All in all this period was really challenging (stressful) - yet having unreliable CGMs was still much better than my previous 12 months with no CGM. Each failed Libre 2 was replaced by Abbott - time consuming for me making phone calls and sometimes leaving me with no CGM, because of the 2 only per month rule and my having no buffer stock.
My CGM was on prescription. In 2021 there was no viable CGM alternative. My GP wrote the prescription but the authorisation came from a Hospital Consultant. In spring '22 NICE updated their Guidelines (NG17 & NG28) making prescribing available to GPs without needing a Consultant's approval AND widening the choices. Now there is officially sanctioned recognition that some patients find their prescribed tech is incompatible with their bodies.
I am an example of someone incompatible with Libre 2; my Consultant agreed.
I was changed to Dexcom One, the 2 part system with sensor and transmitter being clipped onto each other, providing a 90 day system, rather than the 14 day Libre 2. Dex One was much more consistent and reliable, but not perfect.
After 9 months, as a trial I self-funded Dexcom G7. Suddenly I had an exceptionally reliable CGM. The difference was amazing. G7 worked for me. My single problem occurred when I was in France and the "clever, new to G7, geolocator tech" decided I was wearing a CGM in a country where it was not licenced and froze my app. I finished my trip by reverting to finger pricks. Dexcom said this "couldn't happen" but provided me with their hand held Receiver for free, plus 2x sensors, marketed by them at £250. They never admitted liability; the geolocator problem has happened twice more in France and Germany, but not a problem for me because the Receiver works completely independently of the app.
My Consultant accepted that my self-funding of G7 had proved that G7 was right for me and the Hospital took over my contract. Huge financial relief for me. G7 is in the higher tier of funding costs for the NHS. So GPs can't authorise G7 unilaterally, whereas they can prescribe Libre 2 or Dexcom One+, without any reference to a Consultant.
I found Dexcom One good, but not brilliant. G7 is simply brilliant, for me. Accurate, reliable (apart from the geolocation issue when overseas) and has been a life changer for my BG management.
The G7 Alerts (equivalent to Libre's Alarms) are comprehensively superior to Libre, providing a wide choice of sounds and far better Alert choices. Vitally the upper low limit for G7 is 8.3 mmol/L, versus Libre's 5.6. If your BG is routinely stable this might seem an insignificant matter. I can crash from mid 7s to low 4s very quickly, particularly after a lot of exercise. The G7 report on the phone app are not as comprehensive as Libre, but are all available from their Web based Clarity. G7 on my phone allows me to rotate my graph form portrait to landscape view; another modest bonus with the usability of G7 data.
Yesterday evening my low Alert told me I was dropping below 6.5 and an extra Alert told me I was dropping very rapidly. I intercepted this rapid fall turning it back up at 4.2 on the sensor, confirmed by fp. Looking back on my graph I could see this crash started when I was mid 7s; unless I'd been watching my phone app, I would not have seen that first tumble downwards on Libre with its unhelpful alarm at 5.6 and would inevitably have gone hypo. After a rigorous gardening spurt between 5-8pm, then supper, I had 5 BG rapid falls between 9pm and midnight. Each intercepted successfully, finally stabilising a little higher than I would have liked at 12, but while I slept that was gently recovered and I woke at 7am at 6+mol/L. A very satisfactory BG management period, caused by my stone crushing and path making work in the garden and adequately managed thanks to G7 - allowing me to have a normal(ish) day, despite my diabetes brittleness.
The Integrated sensor and transmitter of Dexcom One+ is very helpful, in relation to the 2 part (90day) Dexcom One. If your current CGM is prescribed by your GP you should be able to request a switch to Dex One+, as a trial, with minimal admin fuss. Dex G7 is only prescribed by Consultants since it's in the higher tier cost bracket for the NHS. Because G7 is a 10 day, then throwaway, system you could consider self- funding G7 for a month (ie 3sensors) and then compare for yourself the pros and cons. Check your phone is compatible with G7, visit the Dex G7 site. My sensorscare sticky, but bio oil makes that a non-problem.
