I'm almost done with the first of 4 boxes of my latest Dexcom shipment, and each of those sensors have lasted 7-8 days and no more. My last sensor got the pink slip after it failed to alert me to a 35 mg/dL low and my current sensor started giving me "Sensor Failed" after I restarted it after its first 7 days.
My diligence to try to extend my sensors has only led frustration and lack of valid data for 10 of the past 24 hours. After 2 hours of "???" post-dinner, I was about to change out the sensor before bed. But it came back to life for 30 minutes. When I gave it my bedtime BG test, it responded with "Sensor Error #1", which standard protocol calls to wait one hour and try recalibrating. Not willing to stay up for another hour, I simply turned off the receiver with intentions to try to recalibrate it the next morning.
I turned the receiver back on and gave it my morning BG reading, and again I got "Sensor Error #1". "Fine! Die on me on Day 8! See if I care!" So I pulled the sensor out and put a new on post-shower (so it was half a free shower day). Two and a half hours later, it prompted me for my 2 BG readings.
I really don't like when I don't have a CGM overnight, but luckily my BG behaved. I know I shouldn't get upset about my sensors doing exactly what they're supposed to do--lasting 7 days. But the frugal side of me still wants to make these things last as long as possible.