Dexcom Seven horrible experience

I have had a horrible experience with the dexcom seven and I feel the company could care less. I never really felt the system worked. I had sensor failing problems and constant calibration problems from the very first session. My calls to customer service were brushed off and the onus was always put back on me - send us your data; calibrate more often; don’t sleep on your stomach. I used the system only a few times because it was so much of a hassle and the benefits were next to none as the system was horribly inaccurate. Jump ahead six months and I find myself preggo (only lasted a few weeks :frowning: ). So I get back on the system with as much aggravation as ever. At the Dr.'s office I complain about the dexcom and he is surprised that I have so many complaints. We try to download the info and it doesn’t work. Oh, and I should mention that this is all out of pocket for me - $400 receiver, $60 sensors and $.67 test strips. He urges me to call and try to get a new one. I play by all the rules and do all of the suggestions and still no resolutions. My Dr. lends me one from his office and it actually works! I was amazed - I really just thought dexcom had bribed to FDA to get approval. I give my system one last shot and it is a total and utter mess. I get tough with dexcom and they brush me off with a “sorry you are out of warranty.” I am so frustrated!!! How do they expect to make money? I would have happily shelled out $3000+ per year for a functioning system. I don’t really understand how not replacing my nonfunctioning receiver can make any business sense.
I would love to hear if anyone has had any luck with getting something done at dexcom. One of the reasons I am out of warranty is because they gave me the run around for months and my warranty expired during this time. If anyone has any suggestions I am all ears.

Crap. Are you saying it was your receiver that caused the issues? I’m having similar problems with a lot of failed sensors, etc. So far with me, they have been really great about doing whatever they can. They’ve replaced my transmitter once and practically offered to do it again, but I was hesitant b/c I don’t think that’s the issue. Are you convinced that your issue was really with the receiver? I have good sessions sometimes. It’s just rare right now. So, do you think it might have just been a good (or lucky) sensor when you used the one from your doctor? If you think your issue was really with the receiver, I might try to get my receiver replaced. (I’m still under warranty.) I don’t have much advice for you except to say maybe try again (only they’re $600 now) and follow up more closely during the initial months until it is really working. :-/

I have always had a good experience with Dexcom Customer server, except for lately, but that’s not about an equipment issue.

Anyway, in any customer complaint situation DO NOT RELY ON THE PHONE. Rely on the written word. Document everything. To the extent you can write down the dates of your calls to customer service and your memory of what happened. As you make more phone calls write this stuff down. Follow up every phone call with a letter. Maybe not every phone call, but don’t let more than three go by without sending a letter confirming everything that’s been said in the phone calls since the last letter.

Start a writing campaign immediately focusing on two things. First - begin each letter by telling them exactly what you want. e.g. I am writing to request a new receiver - replacement system - honor my warranty. Whatever. Second - hammer away on the point that you are only out of warranty because the customer service reps kept putting you off. Third - remind them that you’re not looking for special treatment or a bargain or a discount or a freebie- you just want what you paid for. Remind them how much you paid.

Tips: Always be polite and reasonable. Praise the company or its reps where appropriate. Make them want to keep you as a customer rather than want to get rid of you. I don’t mean to roll over, just don’t be a complete ahole. DO NOT call them aholes, incompetents, thieves and the like, even if you want to. You want to be a pest, not a jerk.

DO NOT WRITE TO THE CUSTOMER REP or the SUPPORT DEPARTMENT. Their job is to put you off. Go right over their heads and write to the president of the company. Research will help you find out who that is. (Hint: He does not want to hear from you about bad stuff. He will pass your letter on to someone who can ‘take care of it.’ Do not write to anyone else until you are contacted by a person from the company who is not in the customer complaint department.

DO mention that you have ‘unfortunately had to complain’ about your treatment at a popular diabetes web site and that you regret that you had to do that.

Terrance H. Gregg
President and CEO

Steven R. Pacelli
Senior Vice President of Corporate Affairs

Dexcom, Inc.
6340 Sequence Drive
San Diego, CA 92121

Agent for Service of Process: (copy these guys on correspondence. This tell the company you know where to go if you’re going to sue them.)

Thanks for this information, Terry.

I had a similar feeling/experience with the Medtronic CGMS, but the customer service at Medtronic was fantastic.

I had major issues when I started using the sensor and just never felt it useful or truly got use to or saw it’s benefits, but others swear by it.

Customer Service at Medtronics has always been great for me, but I still have six sensors I have never used.


If you’ve had good results from your MD’s system, then it’s not a problem with your site selection. The MD’s system working well, combined with large number of Sensors which you’ve used with YOUR set, all with pretty much the same “garbage results”, inidcate that it’s not the Sensors.

If the Receiver is showing any data at all, then it’s not the receiver-- and that leaves the Transmitter. It’s the Transmitter’s job to measure the voltage/current, and then send it wirelessly. Your description sounds like the wireless communications in both directions is just fine (please clarify if it isn’t). So I think that the Transmitter in your kit is just incapable of measuring correctly-- due to some loose connection inside, or some unwanted short circuit, or a “failed” logic chip-- it just isn’t dependable.

So here’s what to try first: Since the MD’s kit works for you, try borrowing it for another week. Although all that you really need to have is the Transmitter. Re-code your “maybe bad” receiver to communicate with MD’s Transmitter, put in a new Sensor, and clip it in carefully, and see what happens.

If it works, then you’ve got a “smoking gun” against the Transmitter. And, since there’s this long record of failure combined with current proof that your technique and site choice and usage and everything ELSE is rock-solid, they should give you a new T. (You complained promptly, WITHIN the warranty, and have no created manifest evidence that it’s a product defect-- with no help from their “support”.)

Announce that you’ll tell the FDA of Dexcom’s shipping broken equipment if they don’t handle the problem by sending you a new one immediately. That threat will make them JUMP, probably-- Dexcom doesn’t want a long and slow and expensive FDA investigation of their “possibly defective” Manufacturing/QA process.

Please post right away if this proves it to have been the Transmitter, or if you’ve still got bugz.

I would raise this issue to the company president, Terence Gregg, with all the documentation and dates you can. I tried to get a demo of the unit and I was so frustrated I contacted him and he got back to me. His email should be, I tried to find his email to me to get the actual address for you, but I must have deleted it. They use first initial, last name for their email addresses and this should work.

With the economy the way it is, Dexcom should be protecting their reputation.
Good luck!

I don’t know why I never considered the problem could be with the transmitter, but I guess that could make sense. Dexcom CS certainly never suggested it either.

I have been very cordial with the company and with the people I have been in contact with. I mostly use email as a form of correspondence and therefore am able to keep documentation on file. I basically was shrugged off until I sent an email stating that I felt compelled to share my experience with the company here, on Yahoo cgms groups and with the FDA. I received two calls from very concerned parties at dexcom. I waited a day until my anger subsided a bit a returned the call to the woman who trained me. Basically it came down to this: she felt she could help me work out the problem and get a new system if I wanted/needed one, but I ultimately came to the point where I needed to rid my life of Dexcom. I have had nothing but negative experiences with it from my very first session and after being so let down and angered by CS I just couldn’t go back. It isn’t a pleasant to be attached to the system even if it is working, and it’s one more thing to manage and carry around - negatives even if it is supplying good data. I guess it’s kind of like getting food poisoning at a mediocre restaurant - why the heck would I ever go back. I just have such a bad taste in my mouth I want nothing to do with Dexcom. So I told her there was nothing she could do to get me to buy anymore supplies from that company - I’m done. I will be filing a complaint with the FDA because I truly feel the system did not work properly and Dexcom did not sufficiently attempt to fix the problem. But that will have to wait until I have more time in January. Thanks for all of your comments and suggestions. I really hope none of you have the same experience I did with dexcom.

One example of how off my numbers were: I woke one morning not felling very well and my receiver was showing numbers in the 290s. I checked my sugar and my meter gave me 55 mg/dl. I emailed the company that morning and I was told that I should not sleep on my stomach or on the side where the sensor is. Not only is that not helpful but it is just plain dangerous. I mean really what is the point of wearing something that uncomfortable and expensive if it is going to give me information like that? It was unusual for my numbers to be this off but I frequently saw my numbers off by 50 to 100 points.

Good luck to all of you and thank you for letting me share my experience and vent.

Excellent advice, Rick.

I also had a transmitter problem, but unlike Dwyer’s case, it was Dexcom and the rep who identified the issue and promptly switched out the transmitter.

Get this evidence, Dwyer, especially the proof that you complained within the warranty period and go get 'em.


Thanks, Dwyer, for coming back with the feelings this whole experience with their support has caused, “like getting food poisoning at a mediocre restaurant”. Good Vent! Like Terry, above, I’m appalled the Dexcom “support” never thought to try this quick, simple isolation procedure.

If “support” is gonna be clueless bozos reading from a script, this NEEDS TO BE IN THE SCRIPT. When someone explains “I always get great results from my MD’s loaner,” their usage is not wrong. Dexcom should have either (a) swapped EVERYTHING and re-verified the in-question components in San Diego, to find which part is busted; or (b) take advantage of the already local “demo system” and proceed as I described. When mere users like me are better than “support”, that’s not good.

Dwyer, be sure to give Dexcom the URL address of this Thread, so that they can see all of this. I would actually encourage you to hold off on the FDA attack dogs until after they see all this: it creates a nightmare which I feel Dexcom should have one more chance to avoid-- by refunding all of your payments (start up kit; sensors; shipping charges; everything), with a letter promising to change, and describing they changes they will make.

Otherwise, THEN, let fly-- they’ll probably get to write the same letter to the FDA (about changes they will make), but with vastly more detail required, and excruciating costs incurred.

What a horror story, and I am in the process of appealing my Ins. rejection (Medicare Plus Blue) located in Michigan
I’m going for the Navigator.
I research the Internet almost daily. Lots of negative remarks, but even more positive remarks. Its no surprise Ins. Co’s. reject CGMS. I guess I would also.
I was so confused when I began learning about CGMS, but now that I have become informed, I find myself just as confused.
I have very serious problem with sleep time hypos. They are getting worse.
Any suggestions?

Same here. I’ve had major problems with this device. After five to six months of wearing the dexcom receiver started giving me false information. After 2 months of being told it worked just fine when my blood sugars would go to 24 and 29 while the receiver read 129 -150 I finally became so angry that I demanded a replacement. The tech person told me she couldn’t send a replacement but then went and asked her manager who finally said she would send one. Unfortunately it was a used receiver with gauges and slashes on it. So I told my diabetic trainer and she became upset with the company and they sent me a different receiver which was another used product and did not work properly. Somebody elses problem again. I then requested a brand new receiver and they again wanted to test the one they sent me but I do not have time to deal with this anymore so I told them to ship me a brand new receiver and just believe me, the customer, that the receiver did not work. Every single time I get on the phone with these people it takes at least a half hour and I cannot take time to deal with them anymore. I became infuriated when she wanted to take more of my time to figure this out. I am the customer and the company sells medical equipment that I have already lost 4 months on my warranty. They send out used equipment to replace the equipment that does not work. What kind of idiots work at this company? They still need to honor their warranty and they don’t seem to get that part of the deal. Unbelievable!

I just found this on the Web while Google searching for complaints about the DexCom. I just got one. I’m on my second one. The first one I got, which was a trial one lent to me by a DexCom representative, kept losing its signal and after 3 days, the needle was poking me and I had to remove the sensor. I was going to just forget about the whole thing but then they offered me a month’s free trial (personally I think they are desperate to sell these despite the problems). As I sit here typing this, my DexCom receiver is giving me the ??? again and this is the fourth time today. The needle is in properly, and the signal is strong but it’s still not working. Personally, I really cannot see forking over $325 (I think it is) for this system. My insurance will cover 80 percent of the cost of it, but if I still have to check my blood sugar with a meter each time there is a question with the DexCom reading–which happens more often than not–I personally do not see the point of buying this device. I have had Type 1 diabetes for 15 years, diagnosed April 1, 1996, at the age of 30–an odd age, I guess, but I had DKA and a blood sugar level of 858 when I went into the hospital and was there for a week, so I do have Type 1. I have had no complications in all these years, whatsoever, due to diligent blood glucose monitoring. My old system was more useful than this DexCom. I am not impressed.

Betty, this is interesting. I just found this site and posted a reply about the DexCom. I am glad to know I am not the only diabetic having problems with this device and I personally am wondering if it’s even worth it to purchase it. One thing I put in my post, I am not impressed with it at all!

Dwyer, I just saw this site and was so glad to read that I am not the only one having problems with DexCom. I am on a month’s free trial of this device and am already very disgusted. My numbers have also been off by at least 50 points. What is the point of having a system like this when it’s so often wrong? I agree about not wanting to wear it at all. At this point, I’d just rather prick my finger again. It’s much more accurate and at least I know that I am getting valid data to make treatment decisions. Imagine if you had taken insulin with that reading and not checked it with your blood glucose meter. Very, very dangerous.

I have been using a CGM for one year now. During this year I have not had even one hypo event.
It is a constant remender but to me it is worth it.
My Ha1c has gone up to 6.2 due to no very lows anymore,
My wife loves it. She can now go out of town without worry.
Generally the receiver reads well within 20% of the blood reading. It does not replace finger stick. It is not intended too.

I have had the Dexcom for one year and experience none of your problems. If I did I sure wouldn’t want to use it.
My concern was hypo events and I have not had even one since I started the CGM.
Previously, they were frequent.

Jim, I am glad you have not had any problems with the Dexcom. I made the decision that it is just not for me. Fortunately, I have been able to maintain great diabetes control with no complications without the device. My HBa1cs have all been under 7 percent since diagnosis 15 years ago and I’ve had no complications whatsoever. I check my blood sugars every day at least four times a day and luckily I have not lost the ability to identify any lows. I can see how the Dexcom would be helpful to identify low blood sugars coming on, but I just never had any luck with the device. I actually called the gentleman at the FDA about it, Dr. Raymond Brullo, in Irvine, CA. He said that they are concerned because Dexcom previously did not report adverse effects to the FDA and had to be forced to do so, and they are up for their annual review again this year and they will be looking at manufacturing quality and so forth, including the issue of accuracy. Previously, they looked at the sensor wires breaking off under the skin. There were 73 cases of such problems, but Dexcom fixed the problem. Actually, the whole issue of CGM is still fairly new and as with any new technology (remember early computers?) there are always glitches to still be worked out.

Janice, I appreciate your response.

There is most certainly room for improvement with the Dexcom which will occur in time.

Before using my CGM my A1C was slightly lower than 6.0 for more than a year, tested every three months… People assumed I took excellent control of my condition.

The reason for these low numbers was the frequent glucose readings in the 50’s and 60’s and I have hypo. unawareness.

I also had very low reactions somewhat often. Lucky for me, my wife had become most adapt at bringing me back with a Glucagon shot.

No more glucagon shots now. My wife loves my CGM, as you can easily imagine.

After starting the CGM my A1C has been around 6.3.

My Endo., who recommended the CGM, tells me I’m now at far less risk for related problems.

The CGM has been a life saver for me.

I realize this posting was older BUT I have had a barrel of grief with this unit. On top of it; I have complained to FDA of the errors and shortcomings.


Semsor not reporting properly after inserting new sensor and waiting for 2 hours.

Readings are bad until at least another 3 hours. This has repeated on each new sensor.
I have had unit receiver unit swapped out by dexcom and second unit works worse.
Receiver Unit overheats inside and flatlines. Chilling it back down stops that and unit recovers.

Unit misses faster cycles of BG due to pancreas activity and over smoothes data.

When unit is out of condo environment; I have my best working whereby I drove all over town, walk costcos parking lot and building; multiple hours and unit tracks handhelds to 2 to 10 units no sweat. Driving 5 hours on 14/395 in boonies - same issue - excellent tracking to 2 to 10 points across 6 hours and meals and up/down cycles.

Sitting in Condo - many times receiver has wondered off track with 20 to 30 points off - requiring loading cal BG’s frequently.
This unit was supposed to reduce finger pricks and costs - not so, I am constantly cross checking this flake product.

I have contacted FDA without any success or assistance. I do not know who these folks are protecting? Not me and not the 13 folks killed on a PQQ technology BG handheld meter and strips in hospital setting. Hospital has proper analytical tools to cross check results before big insulin injections. What does FDA do - says not for use for hospital setting but you folks at home can use this stuff ( with no cross checking tools). My sample of the suspect meter and strips routinely is out from +20 to + 150 points on eating my grub from major grocery chain.

Put me down as disgusted.

FDA saya get a 3rd unit dexcom receiver and try. Did request weeks ago - no success. Dexcom not sent requested 3rd unit. FDA could care less.