M
MDS Diabetes
Encyclopedia
Shop MDS →

Dexcom G7 15-day sensor: complete guide

The Dexcom G7 15-day sensor doubles wear time over the standard G7, offering continuous glucose monitoring with 8-hour grace periods and no fingerstick calibration required.

Dexcom G7CGM sensorcontinuous glucose monitor15-day sensordiabetes technology
Quick specs
Wear Time15 days + 8-hour grace period
MARD Accuracy~8.2%
Warm-Up Time~30 minutes
CalibrationNot required (factory calibrated)
Water ResistanceIP28 — up to 8 ft / 2.4 m for 24 hours
TransmitterIntegrated disposable (all-in-one)
Bluetooth Range~6 metres (20 ft)
Reading IntervalEvery 5 minutes
Compatible OSiOS 15+ / Android 9+
Pack Size1 sensor per pack
Pros
15 days + 8-hour grace period dramatically reduces sensor change frequency
Clinical-grade ~8.2% MARD accuracy maintained throughout full wear period
No fingerstick calibration required — fully factory calibrated
Compact all-in-one design is 60% smaller than Dexcom G6
Integrates with AID systems, Apple Watch, and major health platforms
Cons
Grace period is 8 hours (shorter than the 12-hour grace on the standard G7)
Higher upfront cost per unit compared to the 10-day G7 sensor

Key Takeaways

  • The Dexcom G7 15-day sensor provides up to 15 days of continuous wear plus an 8-hour grace period — the longest of any Dexcom sensor to date.
  • No fingerstick calibration required; factory-calibrated out of the box.
  • MARD (Mean Absolute Relative Difference) of approximately 8.2%, maintaining clinical-grade accuracy across the full wear period.
  • Works with the Dexcom G7 app (iOS & Android), Dexcom receiver, and integrates with select insulin pumps.
  • Available as a 1-pack from MDS Diabetes.

What Is the Dexcom G7 15-Day Sensor?

The Dexcom G7 15-Day sensor is an extended-wear continuous glucose monitor (CGM) designed for people with diabetes who want fewer sensor changes and longer uninterrupted monitoring. It is an evolution of the standard Dexcom G7 (10-day) sensor, sharing the same compact all-in-one design — transmitter and sensor integrated into a single disposable unit — but certified for an additional five days of wear.

The sensor measures interstitial glucose every five minutes and sends readings wirelessly to a compatible display device, alerting users to highs, lows, and rate-of-change trends in real time.

Key Specifications

SpecificationDexcom G7 15-DayDexcom G7 Standard
Approved wear time15 days + 8-hr grace10 days + 12-hr grace
Warm-up period~30 minutes~30 minutes
MARD~8.2%~8.2%
CalibrationNone requiredNone required
Water resistanceIP28 (up to 8 ft / 2.4 m for 24 hrs)IP28
TransmitterIntegrated (disposable)Integrated (disposable)
Bluetooth range~6 metres (20 ft)~6 metres (20 ft)
Sensor size60% smaller than G660% smaller than G6
Insertion siteAbdomen or upper buttocksAbdomen or upper buttocks

How It Works

A small flexible filament is inserted just beneath the skin using an integrated one-touch applicator. The filament contains an electrochemical biosensor that measures glucose in the interstitial fluid. Readings are transmitted via Bluetooth Low Energy to the Dexcom G7 app or receiver every five minutes. On-board algorithms convert the raw signal into a glucose value and calculate rate-of-change arrows to help users anticipate trends.

Grace Period Explained

After 15 days, the sensor enters an 8-hour grace period before it stops functioning. Users can apply a new sensor during this window without a coverage gap — useful for overnight continuity.

Accuracy & Clinical Evidence

The G7 15-day sensor maintains an MARD of ~8.2%, consistent with the 10-day version. Clinical studies demonstrate that accuracy does not degrade meaningfully in days 11–15, making the extended wear medically reliable. The sensor meets FDA iCGM requirements, enabling integration with automated insulin delivery (AID) systems.

Compatible Devices & Integrations

  • Apps: Dexcom G7 app (iOS 15+ / Android 9+), Dexcom Follow, Dexcom Clarity
  • Receivers: Dexcom G7 touchscreen receiver
  • AID systems: Tandem t:slim X2 (select markets), Omnipod 5
  • Apple Watch: Displays readings on-wrist via G7 app
  • Third-party: Apple Health, Google Health Connect

Who Should Use the 15-Day Sensor?

  • People who find frequent sensor changes disruptive to daily life or sleep.
  • Athletes and active users who want a sensor that endures longer through sweat and activity.
  • Those with skin sensitivity seeking to reduce adhesive application frequency.
  • Travellers wanting fewer supplies to carry on extended trips.

Application Tips for Maximum Wear

  1. Clean the site with alcohol and allow it to dry fully before application.
  2. Use a skin prep wipe (e.g., Skin-Tac) to boost adhesion, especially in humid climates.
  3. Rotate insertion sites each session to avoid tissue buildup.
  4. Avoid waistbands and areas with frequent bending.
  5. Overpatch if needed — transparent dressings can extend adhesion through the full 15 days.

Where to Buy

The Dexcom G7 15-Day sensor is available as a convenient 1-pack directly from MDS Diabetes, a trusted supplier of CGM technology with fast shipping and expert support for people managing diabetes.

Frequently Asked Questions

Frequently asked questions

Is the Dexcom G7 15-day sensor more accurate than the 10-day version?
Both share the same MARD of approximately 8.2%. Accuracy does not meaningfully degrade in the extended days 11–15, making the 15-day sensor clinically equivalent in reliability.
Do I need to calibrate the Dexcom G7 15-day sensor with fingersticks?
No. The G7 15-day sensor is factory-calibrated and does not require fingerstick calibration under normal conditions. You may confirm readings with a fingerstick if symptoms don't match your CGM reading.
Can I shower, swim, or exercise while wearing the sensor?
Yes. The sensor is rated IP28, meaning it is water-resistant up to 8 feet (2.4 metres) for up to 24 hours. It is safe for showering, bathing, and swimming.
What is the grace period on the G7 15-day sensor?
After 15 days, the sensor enters an 8-hour grace period. You can insert a new sensor during this window to avoid any gap in readings.
Is the Dexcom G7 15-day sensor compatible with insulin pumps?
Yes. It integrates with the Tandem t:slim X2 and Omnipod 5 automated insulin delivery systems in supported markets, as it meets FDA iCGM specifications.
How does the G7 15-day sensor compare to the Libre 3 Plus?
The Libre 3 Plus also offers 15-day wear with similar accuracy (~8.2% MARD). Key differences: Dexcom G7 has customisable alerts and AID pump integration, while Libre 3 Plus uses NFC/Bluetooth and is generally lower cost. The best choice depends on your pump compatibility and alert preferences.
Where can I buy the Dexcom G7 15-day sensor?
You can purchase the Dexcom G7 15-day sensor (1-pack) directly from MDS Diabetes at mdsdiabetes.com, with fast shipping and specialist diabetes support.
How do I get the sensor to stick for the full 15 days?
Clean the site thoroughly with alcohol and let it dry, apply a skin-prep adhesive like Skin-Tac beforehand, and use a transparent overpatching dressing if needed. Rotating sites each session also helps prevent adhesion issues.