Dexcom supply wiggle room

Medtronic Guardian sensors are supposed to last 7 days. But there’s a failure rate. Sensors that don’t work properly or that stop working early. So they give you a spare. They replace failed sensors individually, of course. But just as a rule, a one month supply is a box of 5 sensors that last 7 days each. So there’s some wiggle room.

Dexcom sensors last longer and are more reliable. But I’ve found that for me they often fail a day or so early. It’s not enough that it seems right to call Dexcom for a replacement. On my last sensor, I started getting errors about 36 hours before it was due to expire. It worked to fix those errors by itself, but I had a fair number of alarms waking me up that night and ended up putting in the new sensor 12 hours early. Not a big deal. But a 90 day supply of sensors is 9 sensors. That’s all I get. So if I have to replace each one 12 hours early, that’s going to add up and I’ll end up a few days short before the next 90 day shipment is due.

How do you handle that?

From time to time I buy a box on Amazon or eBay and it’s gotten me through some pinches, that’s for sure! You’re not supposed to buy or sell there and I don’t like to break the “rules” or recommend others do, but I make an exception to have a backup plan. Same goes for pump supplies. Of course I always check the expiration dates and make sure the package is unopened.
I keep a Freestyle Libre on hand as well (Backup Plan B) and I might use it to go off CIQ and go rogue - I mean manual - to stay in practice. That gives me an additional week+ of Dexcom time.
Given the nature of our devices I think one order a year should include one additional box as a cushion (while continuing to replace failed sensors), and each year following that one they should repeat. It would be one thing if you could get them from your local pharmacy but since many of us have to use a mail order supplier this would lesson anxiety.
The replacements Dexcom sends should extend your time to last until your next shipment, no? I always call for replacements - you’re supposed to get your money’s worth - and call me naive but I would like to think the volume of calls would eventually lead to them improving their product and help save on shipping costs - although I imagine that like “big pharma” they make so much money, that’s only a drop in the bucket (sorry for starting to go OT with a mini rant😬).

I agree. There should be an extra sent every now and again.

I should probably call Dexcom. I haven’t yet. Just been dealing with other medical issues and haven’t had it in me to chase them down. Like I said in the OP, calling them to send a replacement sensor for one that had to be changed 12 hours early out of 10 days didn’t feel like enough. But if I explain that I had to change the one before that a day early, too, maybe they will send an extra. We’ll see.

Good to know you can get them on your own. My insurance won’t let me get them from the pharmacy. Every time I called them I got a different agent who gave me a different answer. So I ended up having to get them through a medical supply company, which was a whole other issue to set up. Might have to call and badger them, too, since my resupply shipment is still “processing.” But if I can get a box at a reasonable price somewhere, that could be good backup to have.

Aside from the ones I’ve purchased on my own from Amazon/eBay, I’ve only ever gotten mine from medical supply companies (not my pharmacy). I’m not sure they are available at local pharmacies - apologies if I made it sound otherwise.
Definitely call each and every time you need a replacement - the sensors have a warranty that they are supposed to last the entire 10 days so even if one dies on day 9 call for replacement - it’s your due. Frankly I don’t know that they’ll replace ones that died a while back so it’s best to report at the time it happens. I always speak to a rep although there is an option to make a report online or in writing.
Calling for replacement doesn’t seem like enough but it’s the only option.
I had issues with my now former DME supplier. I’d been with them for years and was happy with them, but they messed me up royally earlier this year. I contacted my Dexcom rep and she recommended a new one, which I switched to recently. Of course they had to do the requisite insurance verifications and get a scrip etc but overall things are starting off well. I’ve learned that the reps can be invaluable, and to let them do some of the initial legwork. They are more familiar with the requirements and how to talk with insurance and suppliers so that saves a load of trouble even for those of us who have a lot of experience with Type 1.

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Dexcom sensors are available from some pharmacies. I prefer to use my insurance company’s contracted mail-order pharmacy, and they do provide Dexcom. However, my insurance classified Dexcom as part of my medical benefits rather than pharmacy benefits, and, while I got a different answer about this literally every time I called, ultimately they decided that that meant I needed to use a DME supplier instead of the pharmacy.

Understood. Thanks for letting me know they may be svailable locally of your plan allows.

I contacted Dexcom, and they said since I’m using a Tandem pump I actually need to get the sensor replacement through Tandem for the issue I’m having. Apparently, the two companies have an agreement about this and there’s a chart over on the Tandem contact page which shows that you need to call Tandem for things like inaccurate BG values, early sensor expiration, and trouble with the Dexcom transmitter cutting out.

Update: Tandem is sending me two sensors!

Glad you’re getting replacements! I totally get not having it in you to chase down one more thing, but whenever you’re up to it, I agree with Dorie about calling every time one fails early. Every time I’ve ever called for a replacement, they’ve been super-friendly and helpful. There’s a list of questions they’ll go through with you every time, and then they send you another one. (And maybe a return kit so you can mail back the one that went bad for analysis, but not necessarily.)

Just doing that — getting a replacement every time one fails early — will build you a cushion, since you’ll mostly get more days out of each replacement than you were shorted by the one that failed early.

With Medtronic, if the sensor was going to fail, it was almost always on the first day. So I got quite used to calling that in as soon as it happened every time. And then they’d be reliable for 6.5 days or so. Here I was getting at least 8 good days out it. I didn’t think they’d replace it that far into things. But Dorie was right; 10 day warranty period means they’ll replace it even if it fails halfway into day 10. (It started cutting out on day 9, kept waking me up in the middle of the night with errors, and then I yanked it on day 10 because it was clear it just wasn’t going to work.) It’s good to have a cushion. Thanks for the support, guidance, and encouragement.

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I actually do call Tandem since I use CIQ, and I guess they’re custody service arranges for Dexcom to send a replacement. I couldn’t recall the details and figured it would be simpler for you to find out on your own than me trying to describe who does what when. Yes, I took the coward’s way out🙁.
Great news about getting your replacements!

Thank you for this post. I get my Dexcom G6 sensors and transmitters through my local Walgreens. My co-pay is $40 per box of three, and $100 for each transmitter. It is annoying when a sensor fails on day eight, which happens to me frequently if I place the sensor on my belly. When I use my arms, I rarely have this issue. I try to discipline myself to call Tandem right away for a replacement, but for some reason, i drag my feet about making that call. I am hopeful that the G7 sensors will be better, but though I’ve the list of improvements, there is no mention of this issue. Anyway, you are not alone - so many of us experience these sensor failures from time to time. It is so helpful to hear others’ experiences!

Having to make those calls in the first place is annoying but I do it right away to get it out of the way and so I don’t forget. The nice thing (if you can call it that) about calling in a failure in the last few days, is you’ve bought yourself some extra time and overlap with your next box (I hope that makes sense). At least that’s something.

So true!! Thanks for your encouragement!

I read more and more complaints about Dexcom products. I’ve been using Medtronic pumps since 1997 and their CGMs since early 2000 and have only called occasionally to complain. I’m more than pleased with the accuracy of their CGM and dealing with one company about an issue is so much easier than dealing with two.

My experience has been very different. I used Medtronic Guardian 3 sensors for 2 years before switching to Dexcom. For me, the Medtronic sensors were a pain. They never did warmup right. It always took 12 hours and multiple calibrations before they got on track. At least 10% of the time it wouldn’t get on track and I’d have to pull the sensor, call in to get a replacement, and start the process over the next day. Calling in, the people were always nice, but the phone maze to get to them was tedious until I finally complained and got a direct extension. (Pretty sure their call center is outsourced to Indonesia or something, too. I can’t quite place the accent, but they’re clearly reading off standard scripts.) Finally, Medtronic implemented a website that allows you to fill in the sensor replacement info yourself, although you can only use it 3 times a month, so I had to call in whenever I needed a replacement more often than that.

Once the Medtronic sensor gets on track, it still needs to be calibrated 3 times a day, and the pump is programmed to ask for a finger stick BG value whenever you want to do a correction bolus. Their sensors last 7 days, although mine usually got wobbly on the last day. So I basically got 5 good days out of a sensor.

Dexcom has been a breath of fresh air for me. It doesn’t need calibration at all. Insert sensor, wait a couple of hours, and it’s ready to go. I do still calibrate daily, just to be sure. A couple of times it’s been a little off on the first day, but a calibration or two usually gets that fixed. Twice I had trouble where it was way off on the first day, but leaving it overnight gave it time to sort itself out and it worked great after that. I always get at least 8 good days out of a Dexcom, and it’s not uncommon for it to go the full 10 without a problem.

When I wanted to call in to Dexcom, they had a live chat option on their website, which was much easier than a phone call for me. But, like I said, it turns out if you’re using a Tandem pump you have to call Tandem for most sensor issues. Getting through to Tandem is easier and faster than getting through to Medtronic customer support, and they need less information from me, too.

In short, the sensors I had trouble with lasted longer than a Medtronic sensor ever would, were more accurate during that whole period, needed much less maintenance/calibration, and were easier to replace. No CGM is perfect, but my doc said she wanted me to switch because “Dexcom is the gold standard CGM,” and I’m glad I listened to her.

Have you tried your upper thigh area? I’ve used the Dexcom G6 for over a year and rotate between legs every 10 days. Highly accurate and never falls off.

I will try that - thanks for the suggestion!

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June 18 |

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Have you tried your upper thigh area? I’ve used the Dexcom G6 for over a year and rotate between legs every 10 days. Highly accurate and never falls off.

I keep my infusion sets in my legs and save my abdomen for the sensors. Sensors in my legs didn’t really work very well with the Medtronic ones. Haven’t tried it with the Dexcom yet. Back of the biceps worked pretty well for me with the Medtronic sensors. But we’re all a little different.

Hi,
This is always what I do–I call Tandem (used to call Dexcom) and report a failed sensor, even if it only lasts, say, 7 days. That way I am also building up a bit of a reserve (so, for instance, I didn’t call them when the sensor only lasted 9 1/2 days). But I agree with the sentiment that there should be a “cushion” allowed (in my case) by Medicare, since it would be quite problematic to run out. Same with pump supplies!