Which do you like better Dexon G5 or the G4?

My doctor wants me on a CGM but I have issues with bulky items on my body. I want to know how long the needless are and how much of it stays inside your body? I have suffered with skin irritation with my pump and want to know if The CGM is known to cause skin irritation. If you guys have a Link where I can do reaserch too that be great I was told of Dexcom.com but all I find is that new app thing they created.

The G5 and G4 use the same sensors. It is only the transmitter that is different, so in terms of skin irritation or adverse reactions there shouldn’t be a difference.

There have been some discussions on here about skin irritation problems - try to search the archives. The vast majority of users seem to have no problems although a small number report irritation from the adhesive. There are barriers that can be applied, check the archives. The sensors are incredibly fine (much finer than an cannula) and because there is no insulin delivery (and the main cause of site problems is reactions to insulin/the preservatives used therein) nobody seems to report problems due to the sensor probe, even when users re-start the same sensor several times so the same sensor can be inserted for more than 3 weeks.

If you do decide to go with Dexcom, check out the archives also for hints and tips as to how to get the best out of them. Most people use extra tape and skin adhesives to prolong sensor life and stop them becoming detached.

This is true. However, the transmitter on the G5 is slightly “taller”/bulkier than the G4 due to them having reworked it so that you don’t necessarily need to have the receiver. Both still snap into the same sensor and have the same footprint as far as how much skin space they take up, though. A side-by-side picture can be found here..

According to diabetescare.net “the DexCom G4 uses a 26-gauge needle for inserting the sensor. The sensor length is 12mm, with a 45-degree angle insertion at a depth of placement of approximately 8mm into the adipose tissue.” 12mm seems long, but that length is accounting for having to go through the sensor unit itself on the way to deploy. I honestly don’t feel the needle that much, even at 26-gauge, as long as I pinch up firmly. The part that actually remains under your skin is very, very fine (remember, it has to fit inside that 26-gauge needle, after all). It looks almost like a fiber-optic filament.

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Dexcom is working to reduce the size of the G5 transmitter so I would not base my decision on transmitter size. For most of us it is s non-issue anyway.

IMO there are three things to consider when making a decision between G4 and G5.

  1. Do you want the ability to use an iPhone as the receiver and not carry the Dex receiver? If you do, you must go with G5. Note that the G4 Share will also link to your iPhone, but you must also carry the receiver.

  2. Do you have good insurance coverage for CGMS? The G4 transmitters are warrantied for 6 months, but can last for a year or longer. The G5 transmitters have drop-dead dates after approximately 100 days of use. You get two G5 transmitters for the price of one G4 transmitter, but you lose the chance of extended life.

  3. Do you want the ability to use an insulin pump as a receiver? If so, both Animas and t:slim have pumps that integrate with the Dexcom G4. Please note that the software in those pumps is currently locked and is not the latest version of Dexcom software. Eventually there may be pumps released that integrate with G5 (Omnipod, Animas, other).


This is my breakdown… all about preference.



I don’t have an Iphone. I don’t want to carry one either. I have the T:Slim G4 so I use that. I do have problems with the adhesive of the Dexcom so I use IV3000 before putting the sensor on, making sure to cut out a hole so the needle can get into the skin. If I don’t use the IV3000 I cannot use the Dexcom.

We most definitely prefer G5 bc it’s one less thing that Caleb has to carry around and deal with.

Caleb had some pretty severe skin irritation with Dexcom years ago. He has never had it with his pump. After a period of months and various trouble shooting strategies, the issue resolved itself and it has not recurred. It’s been five years for him (knock wood).

It’s possible they have changed their adhesive, or perhaps it was just a temporary situation with Caleb.


Many iPhone users enjoy having to carry 1 fewer device. Both work well and the G4 is less technologically challenged. Making it work is easier and the old Dexcom software is still better (even though Clarity has improved). If you are friends with your iPhone and technology the G5 works well and you can use Blip Notes to send your data to Tidepool. This is a big plus that sidesteps dealing with Clarity.

The recent DiaMonD study indicates that adding a CGM before a pump could be a good choice as well for those on MDI. 'Profound' Finding on Continuous Glucose Monitoring

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