What is Dexcom G7 Sensor: Uses, Warnings & Interactions

The Dexcom G7 sensor sends readings to a Dexcom receiver, an app on a smart device (tablet, smartphone, or smartwatch).

To use a smart device, download the Dexcom G7 application and set it up. For the app to receive current data and sound alarms, you must:

• Keep the smart device on

• Open the app and never close it

• Keep Bluetooth on

• Keep the phone or smartwatch charged

• Keep the receiver, phone, or tablet within 33 feet of the sensor at all times

• Keep the smartwatch within 20 feet of the sensor at all times

• Allow no barriers between the sensor and the app device, including walls or water.

• Enable some permissions, such as Location Permission, Notifications, and Critical Alerts

• Remove headphones or speakers from the phone when they’re not being used

If using a Dexcom G7 receiver, set up the receiver following the on-screen instructions.

How to place a sensor:

• Read the Start Here Guide for instructions on how to place the sensor on the skin.

• In adults and children 7 years of age and older, the sensor should be placed on the back of the upper arm.

• In children younger than 7, the sensor can be placed on either the back of the upper arm or the upper buttocks.

• Clean and dry your hands with soap and water.

• Clean the adhesion site with alcohol swabs and let it dry. 

• The sensor comes preloaded in an applicator.

• Do not use the applicator if it’s damaged, has been previously opened, or is past its Use By Date.

• Remove the cap.

• Relax the muscles at the application site.

• Place the bottom of the applicator on the adhesion site and push down until the clear ring disappears.

• While pushing down on the applicator, press the button on its side.

• Remove the applicator.

• Press the top of the sensor for 10 seconds.

• Rub around the patch firmly three times.

• Apply the overpatch that comes with the sensor.

• Press the Pair Sensor button in the app and input the sensor code written on the applicator.

• To dispose of the applicator, ask the pharmacist about proper disposal. Disposal laws vary by location.

After the sensor is in place:

• The sensor will take 10 minutes or less to pair with the app.

• It takes less than 30 minutes for the sensor to warm up. 

• There will be no readings or alerts during this period. Use a BG meter to test blood sugar and make treatment decisions.

• After the warm-up, the receiver or smart device will start getting readings and deliver alerts.

• Keep the site dry for at least 12 hours after attaching the sensor to ensure the best adhesion.

• If the readings do not seem correct, calibrate the sensor using finger stick testing.

• The sensor can only operate in a temperature range between 50°F and 107.6°F and in a humidity range of 10% to 90%.

• The sensor can be immersed in water up to eight feet deep. 

• The sensor cannot transmit through water, so the receiver or smart device will not receive any readings until the sensor is no longer submerged.

• If the receiver has been submerged or out of range of the reading device, up to 24 hours of missed readings may be sent to it.

How to connect the sensor with an insulin pump or insulin pen:

• The Dexcom G7 system is compatible with the iLet Bionic Pancreas automated insulin delivery pump, the Tubeless Omnipod 5 Automated Insulin Delivery System, the Tandem t:slim X2 insulin pump, and the Tandem Mobi System. It is not compatible with any other insulin pump.

• The Dexcom G7 system is also compatible with Medtronic’s InPen smart insulin pen.

• Install the current insulin pump or smart insulin pen app on your smartphone. 

• Pair the insulin pump app with the insulin pump.

• For a smart autoinjector pen, pair the smart insulin pen app with the pen. 

• Follow the app’s instructions to connect the app to the Dexcom G7 system. 

• Most apps will immediately start receiving glucose readings from the Dexcom G7 system.

• You may need to start a sensor session in the insulin pump app. Follow the instructions in the insulin pump system manual. 

Keeping a sensor in place:

• Keeping the sensor dry in the first 12 hours after attachment will help it stay attached for the full 10 days.

• Be careful not to dislodge the sensor. Gently put on clothing. Wear loose-fitting clothing. Avoid hitting or brushing objects with the sensor arm. 

• After swimming, showering, or bathing, pat the area dry rather than rub it with a towel. 

• When washing the arm, pat but don’t rub with a washcloth. 

• Don’t play or fool around with the sensor.

• Exercise or heavy sweating can loosen the sensor.

How to replace a sensor:

• Replace a sensor after 10 days. 

• When the 10 days elapse, you have a 12-hour grace period to replace the patch. You can wait the 12 hours or remove the sensor manually. 

• At the end of the grace period, the receiver or app will display a Start New Sensor screen.

• A sensor will need manual replacement if it fails, falls off, comes loose, or you can see the tip. 

• When replacing the sensor manually, start by ending the sensor session in the app or receiver.

• Carefully and slowly peel off the overpatch as you would a bandage.

• You can use products that help remove the sensor, such as baby oil or adhesive dissolvers.

• Carefully remove the tip from the skin.

• Ask the pharmacist how to dispose of the sensor. Disposal laws vary by location.

• Choose a different location to attach the new sensor. 

• Follow the instructions for applying a new sensor.

• In the app, input the sensor code written on the applicator.

How to share information with a healthcare provider:

• Read and follow the instructions in the Dexcom G7 User Guide.

• Using the app or the receiver, invite a healthcare provider, other members of your healthcare team, or caregivers to join as Followers.

• The setup screen will take you through the kinds of data you want to share with each individual Follower.

• Followers may see old data, so always use your current information to make treatment decisions.

How to store unused sensors:

• Store unused Dexcom G7 sensors at room temperature or in the refrigerator between 36°F and 86°F and humidity levels between 10% and 90%.

• The sensors may not work properly if exposed to temperatures or humidity levels outside this range.

• Store the sensors in the refrigerator if the room temperature gets too hot.

If you have forgotten to replace a sensor, do it when you remember. 

The sensor has a 12-hour grace period at the end of 10 days. During this grace period, it can still send valid readings to the readers.

Beyond the 12-hour grace period, you will not receive readings.

If you don’t have a sensor attached, use another method to measure glucose levels.

Remove the Dexcom G7 sensor, transmitter, receiver, or smart device before any MRI scan or high-frequency electrical heat treatment (diathermy). The scan or therapy may damage the sensor.

The Dexcom G7 should not be used during a CT scan unless:

• It is out of the scanned area

• It is covered by a lead apron during the scan

Tell all doctors and other healthcare providers treating you that you are wearing a Dexcom G7 sensor.

Before getting a Dexcom G7 CGM System, tell the prescribing healthcare provider if you are pregnant, on dialysis, or critically ill.

Stop using G7 sensors if you become critically ill or are placed on dialysis.

Read all the instructional materials that come with the Dexcom G7 CGM System, including the entire User Manual.

Always use the correct sensor code when pairing a sensor.

Always calibrate the sensor with finger sticks and your blood glucose meter when notified by the sensor. Enter the meter’s reading into the reader or app within five minutes of getting the results.

• The Dexcom G7 sensor does not require calibration when first attached unless the readings seem inaccurate.

The Dexcom G7 CGM System is intended to inform treatment decisions. Follow all the prescriber’s instructions for making treatment decisions with the Dexcom G7. The User Manual has the following general instructions: 

• Use the current glucose reading or the trending arrow to inform treatment decisions

• Never ignore high or low readings

• Do not stack insulin doses based on the system’s readings—ask the healthcare provider how much time you should wait between insulin doses

• Call the prescriber or other healthcare provider if you have any questions or uncertainties

Do not make a treatment decision until taking a blood glucose test if:

• The sensor reading does not display a number or an arrow

• You experience symptoms that do not match the reading

If a sensor wire breaks:

• Call Dexcom technical support

• Do not try to remove the wire from the skin if you can’t see it

• Monitor your blood sugar with blood stick tests

Lying on the sensor may produce inaccurate results.

Dexcom G7 sensors do not interact with drugs. However, some drugs can cause the sensor’s glucose readings to be higher than they actually are. These include:

• High doses of acetaminophen: do not take more than 1,000 mg of acetaminophen in any six-hour period

• The cancer drug hydroxyurea

Avoid sunscreen, insect repellent, perfume, or lotion on the sensor or skin. They can damage the sensor.