Applying a Dexcom G6 sensor takes about five minutes and uses a one-touch auto-applicator that handles the insertion for you. The process has three main phases: preparing your skin, deploying the sensor with the applicator, and snapping in the transmitter. Once everything is in place, the system needs a 2-hour warm-up before it starts reading your glucose levels.
Choose Your Insertion Site
For adults, the abdomen is the approved insertion site. For children ages 2 to 17, the sensor can go on the abdomen or the upper buttocks. Pick a spot that’s flat and free of scars, tattoos, stretch marks, or bony areas. Avoid placing the sensor where a waistband or seatbelt would rub against it, since friction is one of the main reasons sensors peel off early.
Each time you apply a new sensor, rotate to a different spot. Using the same location repeatedly can cause scar tissue to build up under the skin, which interferes with glucose readings over time. A good rule of thumb is to place each new sensor at least a few inches away from where the last one sat.
Prepare Your Skin
Skin prep is the step most people rush through, and it’s the one that matters most for getting a full 10 days of wear out of your sensor. Your site needs to be flat, clean, and completely dry before anything touches it.
Start by washing the area with soap and water, then let it air dry. Next, scrub the site thoroughly with an alcohol wipe and let it dry again. This two-step cleaning removes both surface dirt and the natural oils that prevent adhesive from bonding properly. If you still have sticky residue from a previous sensor, use an adhesive remover like Uni-Solve or Tac Away before cleaning.
If your sensors tend to peel up before the 10 days are over, you can apply a liquid skin adhesive like Skin Tac under the patch before insertion. Just keep it away from the center spot where the needle goes in, and let it dry fully before placing the applicator. Skin Tac is latex-free and hypoallergenic, though people with very sensitive skin may still react to it. Mastisol is a stronger option but is more likely to cause irritation.
Insert the Sensor
Wash and dry your hands before handling the applicator. Then follow these steps:
- Peel off the adhesive backing. Don’t touch the sticky side with your fingers, since oils from your skin will weaken the bond.
- Place the applicator flat against your skin. Press it down gently so the adhesive makes full contact.
- Fold and break off the safety guard. This is the orange tab on the applicator. Snap it off cleanly.
- Press the applicator button. You’ll hear a click. The spring-loaded mechanism inserts a thin, flexible sensor wire just under your skin. Most people describe it as a quick pinch or say they barely feel it.
- Lift the applicator straight up. The adhesive patch and the purple sensor holder stay behind on your skin. The applicator itself is now empty and can be discarded.
If you see blood at the insertion site, don’t panic. A small amount of bleeding is normal and usually doesn’t affect sensor performance. However, if the bleeding spreads visibly through the white adhesive patch, remove the sensor and insert a new one at a different location. Dexcom will typically replace sensors that fail due to bleeding if you contact their support team.
Attach the Transmitter
The small, oval-shaped transmitter is what sends glucose data wirelessly to your phone or receiver. Before handling it, wipe it down with an alcohol swab.
Slide the transmitter into the purple holder on your skin, tab end first. Press it down until you hear or feel a click. It should sit flat and snug, with no wobble or gaps. If the transmitter isn’t fully seated, it won’t maintain a reliable connection and you may get signal loss errors.
Once the transmitter clicks in, run your finger around the edges of the adhesive patch about three times, pressing firmly. This helps seal the adhesive to your skin and improves overall wear time, especially around the edges where peeling usually starts.
Pair and Wait for Warm-Up
Open the Dexcom G6 app on your phone (or power on your Dexcom receiver) and follow the on-screen prompts to start a new sensor session. You’ll need to enter the sensor code printed on the back of the adhesive backing you peeled off earlier. Entering this code means the system calibrates itself, so you won’t need to do any fingerstick calibrations during the 10-day session.
After you start the session, the sensor enters a 2-hour warm-up period. During this time, the sensor wire is acclimating to the fluid under your skin, and no glucose readings will appear. You can go about your day normally. Once warm-up finishes, readings will begin appearing automatically every five minutes.
Keeping the Sensor On for 10 Days
Each Dexcom G6 sensor lasts up to 10 days. The most common reason for early removal is the adhesive losing its grip, not the sensor itself failing. A few strategies help prevent this.
If liquid adhesive alone isn’t enough, adhesive overlay patches provide a second layer of security. Dexcom offers free overpatches through their website, and several third-party options work well too. Transparent films like IV3000 are thin and breathable, making them a good choice for everyday wear. Tegaderm HP sticks more aggressively but can irritate sensitive skin. Hypafix is a thicker, fabric-like tape that tends to be gentler on skin when you peel it off.
For situations where you can’t tolerate any additional adhesive, a non-adhesive wrap like Coban or an elastic band can hold the sensor in place during sports or physical activity. Wrap loosely so you don’t compress the skin, and remove wraps at night to avoid restricting circulation. These work best as a short-term solution for specific activities rather than all-day wear.
Humidity, sweat, and pool water all challenge adhesion. Applying the sensor after a cool shower (when your skin is clean but not warm and pore-opened) gives the adhesive its best starting bond. Avoid applying lotion, sunscreen, or moisturizer anywhere near the sensor site on insertion day.