The big CGM review 2026

I've ordered five CGMs that are currently available in the UK (as of February 2026) to test them against each other in a real world situation. Which is best will depend on your personal requirements and budget, so I'll outline different price points, accuracy, delivery choices and usability.

Limitations of standard blood glucose meters

Standard blood glucose meters involve pricking your finger with a small lancet and supplying a drop of blood to a glucose testing strip that will draw the blood in via a capilliary-like tube. The strip detects the glucose level in the blood and the glucose meter device will give you a glucose reading (in mmol/L in the UK). Around 3.8-7.8 mmol/L is considered to be within normal range. If you have type 2 diabetes, your medical team will most likely suggest a slightly higher target range. If you're used to higher glucose levels you may experience hypo symptoms at slightly higher levels than those without diabetes.

The benefits of a continuous glucose monitor

On 4th November 2024 I received panicked voice messages from my GP surgery as my HbA1c had crept up to 131 mmol/mol which is dangerously high. I had been considering trying a CGM for a few years but I wasn't sure how to get hold of them, which ones to get, or how they worked. I said to my GP that I had been considering getting one and was abruptly told "You don't need one of those." as though I was a naughty child asking for an undeserved gift. It was at this point I decided to take charge of my own health because everything I had been advised to do was clearly not working and I defiantly ordered my first CGM.

The main benefit of a CGM is you can see the overall blood glucose pattern for a whole day so you can very easily see which foods and drinks are causing greater spikes. With a single point in time sample, you have no idea if your glucose is at baseline, half-way up, going down, or at the top of a peak. With a CGM you can log food, drinks and exercise throughout the day and patterns become much more obvious.

The other benefit is that it's much easier to keep well documented readings. Finger pricks are painful which makes doing even three a day a very unpleasant and surprisingly time consuming chore. With a CGM, you have a reading every few minutes automatically logged via an app without you even having to remember to check. You can manually log food/drink/exercise events as much or as little as you like.

CGMs measure glucose in interstitial fluid (the fluid between your skin and muscles/veins etc.). This means that there is a 5-15 minutes lag between rises and falls in blood glucose levels and what your CGM can detect from the interstitial fluid. If you're ever worried or need to measure insulin doses it's always safest to check with a finger prick test using a blood glucose meter.

The CGMs I'm testing

I'm primarily looking at CGMs for managing type 2 diabetes for those who need to self-fund them. For type 1 diabetes, accuracy is more important for insulin dosing so please be aware of that context if you are taking insulin and of course discuss monitoring options with your doctor. Currently, the NHS will only fund CGMs for people with type 1 diabetes or insulin-dependent type 2 and other forms of diabetes. I think this is a real shame because having a CGM can help guide people to type 2 remission which will ultimately save the NHS a lot of money that would otherwise be spent on drugs and hospitalisations from the eventual long term health implications. If you don't have diabetes but want to lose weight then a CGM can be a very helpful tool because seeing what gives you higher glucose responses will be an approximate indicator of how much insulin your pancreas is releasing. Insulin is an anabolic i.e. fat-storage hormone so it becomes an issue if it is chronically elevated. You cannot lose weight if your insulin is always high. I don't think CGMs are a good idea if you have an eating disorder, struggle with anxiety issues, or if you're under weight. It's important to remember that glucose increases are a normal and healthy physiological response and the aim is not to avoid any increases altogether.

Manufacturers quote MARD (mean absolute relative difference) as a statistical measure of CGM accuracy. This is a percentage of how far away the sensor's readings are from laboratory tested blood glucose levels so a lower MARD figure suggests higher levels of accuracy.

If you decide to buy a CGM make sure to check that your mobile phone is compatible with the corresponding app. Most of them will use NFC to activate the sensor so if you don't have that feature you'll need a newer phone first. When ordering there is usually a statement that you have to fill in to get the VAT discounted if you're using the sensor for a medical condition so the prices I've listed are exclusive of VAT.

Abbott FreeStyle Libre 2 Plus

Upfront cost: £51.74

Delivery cost and time: Free 3 day delivery but no tracking.

Duration: 15 days

Effective daily cost: £3.45

Effective annual cost: £1,259.87

MARD: 9.2%

I initially started on the FreeStyle Libre 3 as I was concerned about having to tap my phone on the sensor every time I wanted to check my readings but I think this was only required on much older versions of the Libre 2. In twelve months I've only had one that needed tapping every time I wanted to check so I think this one had a faulty transmitter or low powered battery. I have heard that Abbott are very good at sending replacements if you have any issues with inaccurate readings or if the sensor falls off but I haven't had the need to contact them about any faults yet. They can have slightly unusual readings when you first apply them. Applying them the day before you switch over without immediately activating them will help to alleviate this accuracy issue. The FreeStyle Libre 2 is also thought to have accuracy issues at lower glucose levels. This isn't really a problem for me in managing type 2 diabetes as my goal has generally been to keep higher readings in check. This might be an issue if you're measuring insulin doses for type 1 diabetes or have regular issues with hypos.

The Libre 2 insists you disconnect the old sensor at the time you connect the new one. The new sensor takes an hour to warm up so you always lose at least an hour of data.

The LibreLink app has everything you need to see your last 90 days of data in a variety of helpful graphs. The only issues with it is that the logbook lags badly if you tap on the date to select a specific date. I generally find it quicker to use the left and right arrows to cycle through day by day. The other thing is that the 'Order New Sensors' button doesn't take you directly to the sensor product page and you have to guess the right combinations of web clicks to get to the right product. You can customise your target glucose range and it will give you an estimated HbA1c which I find a helpful guide during the long periods between standard blood tests. I've found that reading is usually within one or two points of my blood test results.

What I didn't realise for several months was that you can access all of your data in more detail using the LibreView website. It shows beyond the 90 days of data limit on the mobile app and also provides more detailed reports. You can also export your glucose data. The one thing I've not managed to be able to do is to produce an export of daily glucose averages which is the only missing feature I find frustrating.

Dexcom ONE+

Upfront cost: £35.00

Delivery cost and time: £4.99 economy 2-5 days with tracking and a 1 hour delivery window.

Duration: 10 days (plus additional 12 hour grace period)

Effective daily cost: £2.60 with 90 day quarterly subscription pack

Effective annual cost: £949.61

MARD:

I have only just looked into the Dexcom range of products as I've always assumed they were more focussed on higher end sensors such as the G6 which is often used by people with type 1 diabetes as it generally considered to be more accurate and can be connected to an insulin pump. The ONE+ has been available for over two years now and saving over £300 per year when compared to the Libre sensors, it's worth trying out. The main disadvantage is going to be the shorter duration time of 10 days. It's not a huge task to change over your sensor but it could be a hassle if you have a busy work and/or family schedule. The 12 hour grace period is going to be beneficial as sometimes you get a gap in data if you happen to be busy or asleep when your sensor runs out. The warm up time is 30 minutes which is an improvement on Libre's one hour.

Dexcom also have a receiver device for £59.99 that might be helpful if you have an older mobile phone that isn't compatible with the software.

Yuwell Anytime CT3

Upfront cost: £88.99 (includes transmitter)

Delivery cost and time: £4.99 Royal Mail 48 hour tracked

Duration: sensor 14 days, transmitter up to 2 years

Effective daily cost: £3.10

Effective annual cost: £1,130.96

MARD: 6.9%

The 12-week starter pack is currently on sale at £150 which includes the transmitter and 6 sensors so that's much cheaper than the £240 price for the standard 12-week 6-sensor pack. That works out at £1.85 per day for 84 days so it will be the cheapest option as long as that sale price remains available. I do think their standard pricing is set too high which negates the advantage of the separate transmitter so hopefully they will lower the standard price point in the future.

Dexcom G7

Upfront cost: £51.25

Delivery cost and time: £4.99 economy 2-5 days with tracking and a 1 hour delivery window.

Duration: 10 days (plus additional 12 hour grace period)

Effective daily cost: £4.60 with 90 day quarterly subscription pack

Effective annual cost: £1,680.11

MARD: 8.0-9.5%

The Dexcom G series of sensors have long been popular with people with type 1 diabetes. They are generally thought of as being more accurate than the cheaper sensor options and provide more detailed data reporting. The previous G6 has the option to be paired with an insulin pump which can help to avoid the need for regular insulin injections. The newer G7 has only recently been able to be paired up with insulin pumps so there may be limited connectivity options.

Dexcom claim the G7 has a MARD rate of 8.0-9.5 compared to around 10-11% for the G6. It's worth noting that this rating might not necessarily reflect accuracy at the points where it matters. For example, Dan Heller has written an interesting review comparing the G6 and G7 and pointed out that the highs and low readings seem more erratic on the G7 which makes insulin dosing more difficult.

The G6 is quite a bulky CGM and at £200 for just 90 days, the separate transmitter is prohibitively expensive if you aren't able to get it on prescription. Dexcom have announced that they are planning to discontinue the G6 so it wouldn't make much sense to start with this if you are just starting out on a CGM journey.

As with the ONE+ the 30 minute warm up time and 12 day grace period is going to be a benefit. There are no free trial options for the Dexcom G series.

The RIZZ ring by Ambrosia Systems

Upfront cost: $499

Delivery cost: $24-59

I paid $59 for UPS Express 2-5 days but this didn't mean I got it much quicker. However, as this is a high value item I did appreciate the tracking when they sent the ring. You also have the issue of waiting for the sizing kit which is sent by standard USPS shipping which lost tracking once it left the US. Other delivery options are First Class(16-29 Days) at $24.00 or Priority(6-9Days) at $39.00

Duration: unlimited

Effective daily cost: Effectively £0 after the first four months.

There is a subscription element to some of the more advanced features which I need to investigate but I don't think you need that for the glucose monitoring.

Effective annual cost: $523 for the first year and then free (£388.11)

MARD: TBC

US-based Ambrosia Systems claim this to be "The World’s First Non-Invasive CGM Ring" and I haven't seen anything like this before they launched this product at the end of 2025. I have recently since seen adverts for similar things but I'm not convinced of how legitimate the alternatives are.

I have always been interested in getting some wearable tech that would monitor my HRV (heart rate variability) as this is another good marker for metabolic health and should be improving with my walking and resistance training routine. I've always put off the idea of getting a smart ring such as the Oura because it just lacked the one massive feature that I really need to make the upfront cost worth it - glucose monitoring.

The RIZZ claims to track:

• glucose
• sleep
• stress
• heart rate and HRV
• activity
• oxygen levels
• skin temperature

The RIZZ ring is currently listed at an eye-watering $499 (around £370 at the time of writing) but I'm looking at this as a potential replacement for my Libre 2 sensors so even at that price it has the potential to pay for itself within four months. Ambrosia are having real problems getting the units shipped at the moment so you will have to be patient. I waited for over three months to get mine and you do need to keep chasing to get your ring shipped. Hopefully their production line will be able to build up as more orders come in.

Another reason for the delay in getting your ring is waiting for the sizing kit to be delivered and no matter which shipping option you pick this seems to be sent via the basic shipping option. If you already know what size you want then you can skip the wait time for the sizing kit and just email them with the size and colour you want. The instructions recommend using the index finger on your non-dominant hand as that will usually provide the most accuracy. You can also use the middle or ring finger. The one thing I didn't really think about with using my index finger is it's more externally facing so easy to catch on things like walls so I'm wary of scratching the ring.

Does it work?

That's the big question I'm going to look to answer over the first two weeks of March 2026 by comparing the glucose readings of these different CGMs and measuring their accuracy against a blood glucose meter. After a few days of using the RIZZ I can tell it's not as accurate as my Libre 2 but I still need to work on the calibration, which does seem to be improving its accuracy. So despite the marketing claims, it does indirectly require needles if you want to use the glucose monitoring functionality as you'll need to do some finger prick tests to do the calibration. You could try using a standard CGM but I wouldn't advise this as it will likely introduce errors into the calibration. Ultimately, I don't need it to be super-accurate, I just want the reassurance that I'm staying within my healthy glucose range as it is so easy to just assume everything is fine when you have no feedback and bad food choices start to creep in. My CGM helps me notice when I'm just unusually high for a day and that feedback allows me to adjust my food and drink choices accordingly. It's also a good reminder to go for a walk! If the RIZZ ring works it will free me from the £100 bill every 4 weeks.

I can't vouch for how good this is yet but if you're keen to try one, Ambrosia are currently offering $150 off the price of the RIZZ as a thank you for your patience while waiting a few weeks on shipping using the discount code D032026.

Honourable mentions

Abbott FreeStyle Libre 3

This is pretty much the same as the Libre 2 but is much smaller and slightly more accurate with a MARD of 8.2%. It's also more expensive so it's worth considering if you have any anxiety about the visibility of your sensor as you will be able to place it in more discrete areas. It could also be helpful if you have any minor skin reactions to the CGM adhesive as it will affect a smaller area. I can't figure out how to buy them directly from Abbott's website (they do like to make it difficult to give them money) but you can buy them on Amazon for around £80.

Abbott Lingo

This is a really innovative product and I loved the idea of the Lingo points being calculated based on the area under the curve. This means it's aiming to measure your overall blood glucose load over time rather than just the height of a spike. I tried Lingo for a couple of weeks but I found it frustrating because it didn't seem to follow any logic in counting up Lingo points for what were considerably high glucose spikes. It is aimed at the wellness market rather than being intended for diabetes management and they are very clear in their marketing about this. It could be a fun way to track glucose levels if you're not dealing with diabetes and are just interested in monitoring your reactions to exercise and foods but I just didn't feel I could trust the readings from it.

SiBio KS3

The KS3 is a continuous ketone monitor (CKM). I haven't tried one of these yet but I am interested in monitoring ketone levels as part of my near-ketogenic diet. Being in nutritional ketosis means that you're metabolising fat efficiently and using ketones as a primary fuel instead of glucose. Diabetic ketoacidosis is a dangerous medical condition which can affect people with poorly controlled diabetes so it's reassuring to know that your ketone levels aren't going too high.

Blood Glucose Meters

The most cost effective and accurate way to check your blood glucose levels is with a blood glucose meter. Also known as a finger prick test - you need to load one of the lancets into the applicator pen and remove the small round cap from the lancet to expose a small needle. The applicator pen usually has a depth setting from 0 to 5 with 0.5 increments so start at 0 and work your way up to the point where you'll get a decent enough size finger prick to be able to slowly squeeze out a few drops of blood. Yes it stings, and that's part of the reason I used to 'forget' to do it regularly. A log book or notepad is handy but for long term use it's best to get an app to log your glucose levels over time so you can see graphs etc. MyNetDiary has an option to log blood glucose with different labels but they all seem to go on the same graph so you can't separate a 7-day average from fasting, before/after meals etc. and it groups all the readings into a single day so there might be a better app for logging several readings per day. More expensive glucose meters may come with bluetooth options to log your readings to an app.

Exactive EQ Impulse

Currently available on Amazon for just £12.59, I've had an Exactive EQ for five years and it's never let me down. I think I replaced the battery in it twice. It comes with 25 strips and 25 lancets and additional packs of 100 of each are currently available at £21.99. If you did three tests per day that would work out at about 65p per day and £236.57 per year in replacement strips and lancets so you can see how much cheaper this option is than a CGM.

KETO-MOJO GKI

I bought a Keto-Mojo last summer because I wanted to check where I was up to with my ketogenic diet and whether I was in nutritional ketosis. I was a bit worried when one of my Ketostix was dark purple so wanted to make sure I wasn't straying into ketoacidosis. Ketostix are urine test strips that test for ketones. They are a cheap and easy way to see if you're in ketosis but they don't show you exact levels.

The Keto-Mojo test strips are £60 on Amazon but they are a bit more reasonable if you buy them through the app at £53.48 for a pack of 60 ketone strips and £19.88 for a pack of 60 glucose strips. If you did three readings of just glucose per day that would work out at £1 per day. Luckily you can use the cheaper lancets with the applicator pen as it seems to be a standard size.

The Keto-Mojo can use Bluetooth to log both glucose and ketone readings to the MyMojoHealth app and you can filter the graphs to show the last 24 hours, several days, several weeks or the last 12 months so it has good visibility for you to be able to look back at patterns. It also has an option to export readings. You don't need to use the app and I've only just got around to installing it so I'll feedback more on the features shortly.