Dexcom g5 - 21 days and counting?

How long can g5 sensors be expected to last realistically? I’m on day 21 and just got the 30-minute expiration warning. The readings have remained accurate.

Can I leave it on as long as its accurate?

Is there the possibility of scarring or infection if I leave it in too long?


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My longest sensor has lasted 46 days.

Most don’t last that long, but I’m able to get a month out of each if my blood sugars are stable enough. If my blood sugars are more unstable, I get around two weeks each.

I pay out of pocket for sensors, so I use them until they totally die (I’ll restart failed a sensor about four times before deciding it’s truly dead).


I’m lucky if I can get to day 12. Most of mine get wonky on day 9, 10, or 11. I wonder if those of us with stronger immune systems (I rarely am sick) attack the sensor, rendering it useless, faster than those with a weaker immune response. I don’t think it’s from having high bgs, as my bg’s average 113.

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In my experience it’s not high BGs, per se, that affect sensor life but rather BG variation. My sensors seem to last much longer when I eat low carb and rarely see angled up or down arrows (and basically never see straight up or down or double up or down arrows) than when I’m eating higher carbs and my blood sugar fluctuates more. But that’s just an anecdotal observation.

I would consider my immune system to be quite strong (I get perhaps one cold a year) and quite overactive (two autoimmune diseases, six allergic diseases, many allergies/sensitivities, including being allergic to most infusion sets and tapes). So I’m not sure it’s a matter of immune system strength, although I think immune systems can definitely “take out” sensors and infusion sets (I’ve experienced the latter many times).

I think part of my success in sensor longevity is because I will put up with a lot of itching, irritation, and inaccurate (or no) data before I pull a sensor I paid $85 for. I’ve not uncommonly had a sensor provide no usable data for approaching a week before I finally got it to turn around or give up, and no amount of physical discomfort will cause me to pull a sensor. I don’t know many other people who would put up with that.

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Sure, you can leave it in as long as it is accurate.

I get 21+ days on my sensors. I don’t think I’ve gotten as many days as @Jen with 46 days (awesome!) but I do get at least 21 and then often go a week or so longer.

I know it’s time to change sensors when I begin to get, what I call hiccups, when the dots (data points) come up missing; or I have really off calibrations; or get the ???.

For me signs that a sensor is dying are either repeated periods of ???, calibrations that are more than 2 mmol/L off consistently, or persistently low results that won’t correct after a few calibrations. Or, quite recently, I had a sensor show a flatline at a perfect 5.8 mmol/L for hours when my blood sugar was actually rising and falling, so that’s also another sign.

During those failing sensor times I’ll calibrate three or four times a day, do the three-calibrations-spaced-15-minutes thing, and then restart the sensor if the above two don’t work. Repeat that about four times. If after the fourth time (usually several days to a week later) the sensor is still super wonky and unreliable, that’s when I change it.

I appreciate your replies. Having just switched over from Medtronic Enlite, I’ve been blown away by the accuracy and longevity. I’m kinda afraid of praising it too much for fear of jinxing myself.

So I’ll just keep on with it and see how it goes. Thanks again!!


I average 2 to 3 weeks based on how well I can keep it on.
My main issues is always adherence rather than a failing sensor / bad readings.
My readings will start going bad when my sensor start moving around too much.
I have had a number of them last 4 weeks and have great readings.

I don’t stretch my sensors out because of money, I have VA and my copay is very little.
I stretch my sensors out because my readings are so stable with xdrip that I only calibrate every 1 to 4 days! Well, after the first couple days of a new sensor where I do calibrate often enough until I know it is stable.

The sensor lasted for 25 days before it started dropping readings. I restarted acouple times, but it had obviously maxed out. There was no skin irritation or scarring. Very easy and simple.

Thanks so much to everyone who responded!