What is Dexcom G6 Sensor: Uses, Warnings & Interactions

Updated May 14, 2025  •  Published Dec 30, 2020

For people with diabetes, the Dexcom G6 sensor continuously monitors tissue glucose levels to help with treatment decisions. The Dexcom G6 Continuous Glucose Monitoring System consists of a sensor, a transmitter attached to the sensor, and either a smart device app or a Dexcom receiver to display, store, and share readings. Dexcom G6 sensors are worn on the stomach area or upper buttocks and last for 10 days before they need to be replaced. Transmitters last for three months and can be affixed to multiple sensors one after another.

Dexcom G6 Sensor overview

BRAND NAMES:

  • Dexcom G6, Dexcom G6 Pro CGM System, Dexcom G7

Generic Names:

  • Continuous interstitial glucose monitoring system (CIGM)

Uses:

  • Continuously monitors tissue glucose levels in people with diabetes.

Therapeutic Classes:

  • Medical device

Forms:

  • Wearable sensor

How it’s taken:

  • Worn on the skin

What is Dexcom G6 Sensor used for?

  • The Dexcom G6 sensor continuously monitors tissue glucose levels to inform and aid diabetes treatment decisions.

What form(s) does Dexcom G6 Sensor come in

  • Replaceable skin sensors

  • Attachable transmitter

What are common Dexcom G6 Sensor doses?

  • For continuous glucose monitoring: Replace the sensor every 10 days; replace the transmitter every 30 days

Common Dexcom G6 Sensor prescriptions

  • Dexcom G6 Sensor
    3 sensors box

How to take Dexcom G6 Sensor

  • The Dexcom G6 sensor and transmitter can send data to a receiver, an app on a smart device (tablet or smartphone), or one receiver and one smart device at the same time.

  • To use a smart device, download the Dexcom G6 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 charged.

    • Keep the phone within 20 feet of the sensor at all times.

    • Remove headphones or speakers from the phone when not in use.

  • If using a Dexcom G6 receiver, set up the receiver and enter the serial numbers of the transmitter and the sensor applicator to read the data from the sensor.

  • How to place a sensor:

    • A Dexcom G6 sensor has two parts: the sensor and the transmitter.

    • In the smart device app, enter the transmitter code (serial numbers). The receiver will ask for both the transmitter and sensor serial numbers.

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

    • Do not use sensors that appear damaged, have passed their expiration date, or whose sterile package has been damaged or opened.

    • The sensor should be placed on the abdomen on either side of the belly button or on the upper buttocks.

    • Clean and dry your hands with soap and water.

    • Clean the adhesion site with alcohol swabs and let dry. Do this a second time to ensure the best adhesion.

    • The sensor comes preloaded in an applicator.

    • Remove the adhesive patch backings at the bottom of the applicator. Don’t touch the adhesive.

    • Do not remove the safety guard until the applicator is on the skin.

    • Place the bottom of the applicator on the adhesion site.

    • For best adhesion, you may wish to press down and hold the applicator at the site for about one minute before pushing the button.

    • Gently fold the safety guard until it snaps off.

    • Press the button to attach the sensor.

    • Remove the applicator and throw it away.

  • How to attach the transmitter:

    • For data to be transmitted to your smart device or receiver, the sensor needs a transmitter.

    • Transmitters can be used for up to 30 days, but sensors are replaced every 10 days. Transmitters can be pulled out of an expired sensor and put into a new sensor if they’re still good.

    • Read the instructions in the Start Here guide.

    • Whether using a new or previously-used transmitter, gently clean the transmitter with an alcohol wipe.

    • Insert the transmitter’s tab into the slot on the sensor.

    • Snap the transmitter into its bed. It will click when in place.

    • Make sure the transmitter is flat and fits snugly in the sensor.

    • Rub the patch in a circle three times to secure it to the skin. 

    • If needed, use medical tape or the Dexcom overpatch over the sensor patch after the transmitter is in place.

    • If using medical tape, place it in a picture frame around the transmitter so no part of the transmitter is covered. Put tape on all sides of the patch.

  • After a sensor and transmitter are in place:

    • It will take 30 minutes for pairing. 

    • It will take an additional two hours for warmup.

    • During this period, there will be no readings. Use a meter to test blood sugar and make treatment decisions.

    • After two hours, the receiver or smart device will start getting readings.

    • To ensure the best adhesion, keep the site dry overnight.

  • How to replace a sensor:

    • Read the instructions in the User Guide.

    • The app or receiver will give you a warning that the sensor has expired and needs to be replaced. Do not ignore this warning.

    • Peel the adhesive patch slowly away from the skin in the same way you’d remove an adhesive bandage.

    • Break the transmitter holder on the sensor at the notches. Fold it so that it completely breaks off to allow the transmitter to be pulled out.

    • Grasp the wide end of the sensor and pull it straight out.

    • Reuse the transmitter in the next sensor.

    • The app or receiver will tell you if the transmitter has expired. Use a new transmitter if the current one is expired.

    • Set up a new sensor in the app or receiver.

    • Affix the sensor to the skin.

    • Insert the old transmitter or a new transmitter.

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

  • How to share information with a healthcare provider:

    • Read and follow the instructions in the Dexcom G6 User Guide.

    • Using the app or the receiver, you will invite people 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 be seeing old data, so always use your current information to make treatment decisions.

  • How to store unused sensors:

    • Store unused Dexcom G6 sensors at room temperature between 36°F and 86°F.

    • Keep any unused transmitter in its carton at temperatures between 32°F and 113°F.

What to do if you miss a dose of Dexcom G6 Sensor

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

  • If the old sensor has expired but has not been removed, you will not receive readings.

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

Dexcom G6 Sensor contraindications

  • Remove the Dexcom G6 sensor, transmitter, receiver, or smart device before any MRI scan, CT scan, or any high-frequency electrical heat treatment (diathermy). The scan or treatment may damage the sensor.

Dexcom G6 Sensor warnings

  • Tell all doctors and other healthcare providers treating you that you are wearing a Dexcom G6 sensor and transmitter.

  • Before getting a Dexcom G6 CGM System, tell the prescribing healthcare provider if you are pregnant, on dialysis, or critically ill.

  • Read all the instructional materials that come with the Dexcom G6 CGM System including the entire User Manual.

  • Always use the correct sensor code when placing 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 G6 CGM System is intended to inform treatment decisions. Follow all the prescriber’s instructions for making treatment decisions with the Dexcom G6. 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

  • Never stack insulin by taking doses within two hours of each other—instead, continue monitoring and wait to take another dose no sooner than two hours after the last dose

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

  • Do not make a treatment decision until taking a blood glucose test with your meter if:

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

  • You experience symptoms that do not match the reading

  • Dexcom G6 CGM System will not provide readings or alarms unless the receiver or the smart device is within 20 feet of the sensor and transmitter.

  • Do not share a transmitter with another person.

Dexcom G6 Sensor interactions

  • Dexcom G6 sensors do not interact with drugs. However, some drugs can cause G6 sensor glucose readings to be higher than they actually are:

    • Acetaminophen: do not take more than 1,000 mg in any six-hour period

    • Hydroxyurea

  • Avoid sunscreen and insect repellant. They can damage the sensor.

Dexcom G6 Sensor side effects

Serious side effects

Dexcom G6 sensors do not cause serious side effects. However, contact a healthcare provider if the sensor wire breaks beneath the skin and is not visible.

Less serious side effects

  • Skin redness

  • Skin swelling

  • Skin irritation or pain

  • Bleeding

  • Infection