Dexcom Setup Step 2: Prepare and apply your Dexcom CGM and Transmitter

If you use the Freestyle Libre CGM, navigate to Setting Up Your Levels with FreeStyle Libre CGM.


Here’s how to prepare and apply your Dexcom CGM.

Please note: Do not apply your CGM during the following times:
  • During or immediately after a meal. A glucose spike during application can impact the accuracy of the CGM. Try to wait at least 2+ hours after eating to apply.
  • Within 20 minutes of ending your previous CGM. If this is your first time applying a CGM, you can disregard this advice.
  • Right before bed. This is optional, but we recommended applying the CGM early in the day to avoid critical low alarms due to calibration in the first few hours

How to prepare your Dexcom CGM and Transmitter

Preparing your Dexcom Transmitter:
  1. If you are replacing an old sensor with a new one, open the Dexcom G6 app select Settings > Stop Sensor to disconnect the old sensor. If this is your first sensor you've ever applied, skip to Step 2.
  2. Find the 6-digit number on your Dexcom G6 Transmitter Box (see image below). If the number is blocked by the prescription sticker, you can find the 6-digit number on the transmitter itself.

  3. In the Dexcom app, enter the 6-digit transmitter number. You can do this manually or take a photo with your phone. This step allows for a Bluetooth connection with the Dexcom transmitter and your phone.
Preparing your Dexcom CGM:
  1. Take one of the CGM applicators out of its package (see image below). You MUST enter the new CGM code in your Dexcom app. 

  2. In the Dexcom app, enter your CGM code (see image below). You can do this manually or take a photo with your phone. You must enter the unique code during startup to avoid a manual calibration. Do not throw away the adhesive patch until you enter the code successfully.

How to setup and apply your Dexcom CGM and Transmitter

How to apply your Dexcom CGM

  1. Pick a spot to apply your CGM. The Dexcom G6 CGMs can be applied to your upper arm or stomach. A few best practices: 
    1. Select a spot with a little extra softness. 
    2. Try to avoid the muscle and aim for a fleshier area.
    3. Avoid these areas: waistbands, scarring, tattoos, skin irritation, and bones.
    4. Avoid areas likely to be bumped, pushed, or laid on while sleeping.

    Members may experience differences in glucose between arms, so we encourage using the same arm for more consistent results.

  2. Clean the spot with the alcohol wipes provided. Let your skin dry fully before applying your CGM.
  3. Apply the CGM:
    1. Orient the applicator in line with your arm lengthwise for the most comfort.
    2. Peel the adhesive cover and save the 4-digit code. You'll need the cover to scan it or manually enter the 4-digit code to start this new CGM. 
    3. Apply the adhesive pad to your skin and press gently to make sure it sticks. 
    4. Bend and break the safety guard to unlock the applicator button.
    5. Let the applicator rest gently on your skin and push the button without pushing down on the whole applicator. 
    6. Once you hear a click, pull the applicator away. The CGM is inserted.

After initial application, it is normal to experience minor bleeding or feel some sensations while getting used to the CGM. If you experience persistent pain or discomfort, please review the following article for more information: FAQ: What if I feel pain or discomfort with my CGM?

How to apply your Dexcom Transmitter

  1. Remove your transmitter from the box. Be sure to keep this transmitter box or take a photo of the transmitter box information on your phone, as it provides important information you may need after you've attached your transmitter.
  2. Clean the back of the transmitter with the provided alcohol wipes and let it dry. 
  3. Slide the tab into the slot (see video above). 
  4. IMPORTANT: Press down firmly on the larger end until it clicks into place.
  5. Set up the transmitter:
    1. Open the Dexcom app on your phone.  
    2. Select Next then Yes to confirm.
  6. Accept the Bluetooth Pairing Request on your phone to connect your transmitter. 
    Note: Dexcom G6 transmitters connect, send data, and disconnect every 5 minutes. The pairing in your phone’s Bluetooth settings will say “not connected;” this is expected.
  7. Select Start Sensor to begin your 2-hour CGM warm-up. During this time, keep your phone in the same room as you, within 20 feet of your transmitter.
  8. After the warm-up is complete, you’ll receive a confirmation. You’ll now be able to see your glucose readings!

Once you setup your Dexcom CGM, select Step 3 below.

Next step: Step 3 - Apply your Levels Performance Cover

See all steps

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