Thursday, March 28, 2013

Dexcom G4 Review

 I've been wearing my new Dexcom G4 Continuous Glucose Monitor for several moths now, so I decided it was time to write a review.  Also, I haven't posted on this blog in AGES, so it's about time it became active again! Sheesh!

So, here's the lo-down on the new G4!

1. Aesthetics

  •  Design! It actually has some! Someone actually took a few minutes to make this thing approach sexy.  Granted, it's not iPod or smart phone sexy, yet. But compared to the Dexcom 7+ and the Medtronic weirdo shell shaped thing, the new receiver design is actually pretty pleasing to the eye.  As one who has been known to purchase a computer solely because the box it came in was very sexy, you can trust me when I say, this CGM is probably the sexiest one out there at the moment. 
  • Color screen- The screen on the receiver is color now. The background is black and all the data is in different colors. White, red, blue. It's beautiful, and much easier to see in the sunlight. Also, the colors correspond to the action you should be taking (i.e. "red" means something you should deal with immediately, etc.). So the color scheme is pretty intuitive for anyone that's grown up in a culture where red means "STOP" or "DANGER".  
2. Accuracy
  • Calibration- Compared to the Seven+ it feels like this little device has a super smart brain that is constantly thinking and adjusting based on the calibrations you're giving it. With the Seven+ it sometimes felt like it didn't give a crap about the calibration you just entered and just decided willy nilly how it was going to report your blood sugar. Not so with the G4!
  • Accuracy- This thing is SUPER accurate in the "in range" levels and is a rock star in the "low" range. 
3. Range-The ranger on the G4 is way better than the Seven+. It is officially listed as 20 feet, and I've never had it loose signal on me once. I live in a two bedroom,  two story town house with a basement (so technically three stories that I regularly use), and I can set it in the living room and wander all around and up and down my house and never lose the signal. And, I've never once lost signal during sleep, which the Seven+ was notorious for doing, even if it was sitting right next to me on the night stand. This little transmitter can transmit through a mattress! Woot!

4. Dexcom Customer Service-I can't say enough good things about this company. They are not paying me to say this, and I'm sure other people have had different experiences. But, they have literally bent over backwards to help me out, and as anyone who's had to deal with a chronic illness knows, that kind of service is rare in the health care world. When I have to call Dexcom up for something, I almost look forward to it because I know they'll be helpful and they won't give me the runaround. 


1. Accuracy- While being super accurate for lows and "in range" readings, it still has a little bit of trouble when you're high. And it can still lag a little bit when you're either rising or falling fast, but I do think it does a better job at keeping up with speedy changes than the Seven+. Additionally, I think a lot of that has to do with the fact that it uses interstitial fluid to measure glucose, which (as all CGM users should know by now), has about a 10 minute lag time compared to a finger stick. 

2. Insertion- Insertion is not painful, and is exactly the same as the Seven+, but the insertion device still looks like an instrument of torture, and I'm sure that the intimidation factor on that thing has got to be keeping people from trying it. Maybe someone can get a designer working on that for the next generation? 

3. Physical Specs
  • The battery life on the transmitter is only 6 months now. I suspect the reason for this is two fold.  First, while the Seven+ touted a year long battery life, I think many people found that it pooped out on them slightly early than that, especially if they used it all the time. Second, the G4 transmitter is MUCH more powerful (longer range) and I think that the shorter battery life has something to do with that. 
  • The profile of the transmitter is slightly higher than the Seven+,which is kind of a bummer. It looks exactly the same, but it's a little thicker now, probably because of the more powerful battery.  The sleek profile of the transmitter against my skin was one of the things I loved about the Seven+, especially compared to the alternative "shell" from Medtronic, so I was slightly sad when I saw  how high the profile of the G4 was. But, it's still way better than the shell, and all the other lovely things it offers make up for it.
So, there you have it. I highly recommend this CGM, without any reservations, to anyone who is thinking about using CGM as part of their diabetes management. It gives me so much peace of mind to know that I can actually TRUST this little machine to do its job, and that in addition to giving me all sorts of helpful information about how my blood sugar reacts to food or life events, the G4 will keep me SAFE.  Here, here, little CGM! Right ho!

*Post script* Since writing this review, I have seen a number of other G4 users have issues with their receiver having parts of the keypad fall off or the cover to the USB charger fall off.  I haven't experienced this at all. I keep mine in the case that came with it and it's usually in my purse near me, not on my person, so I think I'm probably a lot easier on the receiver than people who wear it on their person all day. Just wanted to throw that out there.  I do think Dexcom has been good about replacing them because they realize it's a problem with their design, since the same thing is happening to lots of people.  If I'm wrong about that, someone please correct me. :) 


  1. Thank you for posting this! How high is your blood sugar when you start noticing inaccuracies? Does it at least trend so you know you're going up, or does it just 'miss' it?

    thanks again!

  2. Hi there Patrick. I notice that I start finding the G4 inaccurate around the 140 mg/dl range. And especially if my blood sugar is rising quickly. It definitely picks up the rising trend, but it usually tells me that I'm a lot higher than my blood sugar actually is. So, it doesn't miss it, it's just not as accurate about what my actual blood sugar is as it is when I'm in range or low. Sometimes it is a good 20-40 points higher than what my meter is testing. Hope that answers your questions!

  3. Erin, I am pregnant and my doctor recommends I try this to get my highs under control. My belly is pretty round by now, and I am concerned about what will happen overnight, when I would be unavoidably lying on top of the sensor. What do you think? Thanks! Nellie

    1. Hi Nellie,
      Sorry it's taken so long to reply, I've been out of town! I lie on top of my sensor all the time and it doesn't hurt, and the receiver has no problem picking up the signal from the sensor. Personally, I feel like having the dexcom has helped me maintain much better control during my pregnancy (currently pregnant--21 wks along), and I'm pretty sure it's saved my life a few times from lows I would've slept right through. You might see if a dexcom rep will set you up with a trial for a few days if your nervous about buying one without trying it out first. Whatever you decide, good luck with your pregnancy!

  4. Hi Erin,
    I am 18 years old and I'm getting the Dexcom soon to give me peace of mind for overnight. I was wondering how noticeable it is with clothing and everything? I'm in college and I don't really like when people point out that they can notice some weird device on me.

    1. I don't think it's very noticeable at all. There are two parts, the transmitter (which is attached to your body) and the reciever, which is about the size of a smaller cell phone. The transmitter would only be noticable under your clothes if the clothes you were wearing were pretty tight, but even then, it's such a small little square, that it might be hard for people to notice. The reciever I just carry around in my purse, which is usually close enough to me at all times that it can easily communicate with the transmitter without losing it's signal. The range is pretty good. I highly recommend trying it out. I wish I would've had this in college, it would have given me a lot of peace of mind, especially overnight or when I was by myself. Hope that answers your questions!

  5. Not worth it the customer service is TERRIBLE! I had issues with mine and they said I had to pay for a new one. I have only had it 3 months. I would not recommend them at all.

  6. please do not use or purchase this product in australia from Animas
    the customer support is poor ,once they have your money no one cares
    in 1 year i have gone thru 2 $600.00 batteries plus every 7 days you are up for $120.00

    apart from this if you have an issue animas company who is the only austrlian distributor wipe their hands of you
    it isnt correct in readings plus many other issues
    i would suggest go metronic
    be very aware before you pick dexcom or animas

  7. I am just setting mine up, but cannot believe the narrow band they have for the low alerts. The company should have allowed the customer to enter any low level they feel comfortable with as many diabetics would be unconscious before the default low would ever go off. A simple fix that hopefully they will consider. And monopolies on medical devices should never be allowed.

    1. I'm not sure I understand your comment, as I am able to set my low alert to whatever I want. I have mine set to alert me when my BS drops below 70, and I know that even if you don't set an alarm, it always alarms when your BS drops below 55. Am I missing something, or have they changed this feature? (Not trying to argue with you at all, I truly want to understand what your complaint is, I have't bought a new Dexcom in a few years and are wondering if they changed this . . . )

  8. No Erin, they have not changed it. I just received mine yesterday and it is exactly the same as what you explained.

  9. Has anyone received the letter about receivers which lose the beeper sound and only vibrate? This has happened to me twice and one replacement was shutting off constantly and had to be restarted using a paper clip inserted into the tiny hole on the back. Then it totally died. I have had to wait on the phone for a minimum of a half hour to get tech support. I have had my G4 for over a year and it is a life saver, but when I am low in the middle of the night and nothing warns me, that is scary.

    1. Hi Jack. I haven't received a letter like that. Is that for the G4? I haven't upgraded to the G5 yet so if it's specific for that, I don't have any experience with those. That sounds scary! I personally haven't had that experience, but will definitely be looking into that! Let me know if you find out anything more about it, too! Thanks for commenting!

  10. I just tried the Dexcom 4 Pro for the last week and my opinion is mixed. I love the fact that I know roughly where my BS is but the receiver I had was constantly beeping. This beeping was caused by an error message that would not go away (ERR67) and lead to some very uncomfortable situations. Specifically, while in meetings and it would get three beeps and four buzzes making a very load noise. People thought it was my phone and when it kept happening about every 20-30 min I had to explain that I have T1 and this was a sensor malfunction. This was very embarrassing to have to admit to perfect strangers being T1 just because the receiver was broke. The next thing I am going to try is the Medcom CGM and see if this one is better.