One reason you may get the ??? is the transmitter gets wet from a shower. A way to help this is to think about the transmitter as a ski boot. Always point the "toe" of the boot facing up. This makes it less likely for water to get underneath. I use my thighs almost exclusively and they're pretty muscular but just about any place you can pinch up a decent amount of fat is good. Also if you do get the ??? and you think it is water you can unclip the transmitter and wipe it off with a clean towel or alcohol prep let it dry and pop it back into the holder. It's impossible to do this if it is on your arm because it is a 2 hand process but thigh is easy.
I had three sensors from one box that spent more time with ??? than any readings. One of the sensors failed fairly quickly(Dex replaced it), one lasted one week but only worked 50-60% of the time.
The next one never worked right, and I gave up on it day 2 after the 5th or 6th time it ??? for hours. I am confident it was a bad box.
I am going to save the last sensor in that box for the last one I use before my next 90 day supply reorder. If it gives me issues, I will address it with Dex during my reorder.
I started the replacement sensor that I received yesterday, on my upper thigh, and it has been right on right off the bat.
I exclusively use my thighs, most comfortable for me.
Thigh is the only place I wear my Dexcom G4. And it works super well. Placement-wise, I put it on the front of my thigh, not the side, and about a third of the way down from my hip to my knee. If I put my hand in my jeans pocket, I can trace the outline of the unit at the bottom of the pocket.
With the front-of-the-thigh positioning, I don't sleep ON the unit when I roll from side to side at night (I'm a side sleeper). When I wore it on the side, I got ??? frequently. Since wearing it on the front, it hasn't happened once. I wear it "horizontally". And I never have issues with it getting wet from the shower -- it's never gone to ??? after a shower. I also swim every day, and I've never had ??? after swimming, either.
I shave a spot for it so the hair doesn't pull there. Aside from hurting when it pulls the hair, it makes the adhesive not last as long. I alternate legs each time I change the sensor.
I hope this helps.
Cheers -- Michael
Slight modification to my post, above. It's not exactly on the front of the leg. It is about an inch and a half toward the outside of the leg. I found that when it was directly on top, it would get knocked more often and sometimes ripped off.
Cheers -- Michael
Hi Michael, I'm thinking about giving the inner thigh location a try. Have you been getting two weeks + out of the sensors? My legs are pretty muscular so I've shied away from using them, but from your description of the location you use I've found the "soft spot" where I can see it might work.
I'll be doing lots of hiking next week on spring break, so I'm also a little worried about it rubbing while walking and either being painful or getting the dreaded ???. I appreciate you sharing your experience with this.