If your sensor is defective, you can request a replacement sensor by contacting the manufacturer at:   Dexcom 1-888-738-3646 Freestyle Libre 1-855-632-8658 If your sensor falls off, you can use an adhesive patch to help secure it in place. Visit www.usmeddirect.com/collections/cgm-adhesives to see the different options for adhesive patches for your CGM sensor. You are expected to use the sensors provided and that they should last for 90 days