Dexcom G7

CGM Device Guide

Dexcom G7

One of the two CGMs with the broadest AID system compatibility in the UK. The G7 has iCGM accuracy designation — the highest published accuracy standard — and integrates with Omnipod 5, t:slim X2, and CamAPS FX.

CGM AID

Framework status

5 / 5
All five framework criteria met
iCGM designation: Yes (G7 15-day FDA; G7 10-day meets iCGM thresholds)
✓ T1D included – studied in people with type 1 diabetes
✓ Meal challenge included – rapid glucose rises tested, not just stable periods
✓ Hypoglycaemia challenge included – accuracy tested in the low range
✓ Venous blood reference (YSI) – the gold standard reference method
✓ Population and indication match – adults and children from age 2

Data sufficiency: Met – n=316, 619 sensors, 77,774 matched reference pairs (Garg et al., 2022)

Device at a glance

ManufacturerDexcom
Wear duration10 days + 12-hour grace period (standard G7)
±20/20 agreement95.3% (arm) / 93.2% (abdomen) — readings accurate enough to dose from without a finger prick
Outside ±40/40<1% of readings — the black swan zone. See the accuracy page.
Calibration requiredNo – factory calibrated. Optional calibration available
TransmitterAll-in-one – transmitter integrated into sensor pod
ReadingsEvery 5 minutes, continuous Bluetooth transmission
DisplayDexcom app (iOS and Android) and optional receiver
UK indicationNon-adjunctive (no confirmatory finger prick required for insulin dosing)
Age indication2 years and older (buttocks placement option for ages 2-6)

[Image: Dexcom G7 sensor – awaiting editorial image from Dexcom]

Accuracy

The accuracy figure that matters is the ±20/20 agreement rate — the proportion of readings close enough to the true blood glucose to support an insulin dosing decision without a confirmatory finger prick. For the G7, this is 95.3% at the recommended arm placement in the pivotal trial (Garg et al., 2022). At abdomen placement it is 93.2%. The DSNFUK CGM comparison chart, on which this guide is built, uses ±20/20 and ±40/40 agreement rates as the primary accuracy measures rather than MARD — a statistical average that tells you little about what matters clinically.

The arm placement outperforms abdomen placement in the G7 pivotal data. Dexcom approves upper arm as the primary wear site for adults; the buttock is approved for children ages 2 to 6.

The black swan – when to trust and when to check

Between 0.5% and 1% of G7 readings fall outside the ±40/40 accuracy band – the range where an error is large enough to affect a dosing decision meaningfully. This applies to all framework-qualified CGMs, not only the G7. See the accuracy page for the full explanation of the precautionary principle and when to reach for a finger prick.

AID system compatibility

The G7 has the widest AID system compatibility of any CGM currently available in the UK.

AID systemPumpG7 compatible
Omnipod 5Insulet tubeless podYes
t:slim X2 / Control-IQTandem tubed pumpYes
CamAPS FXYpsoPump (tubed)Yes (G7 integration confirmed)
MiniMed 780GMedtronic tubed pumpNo – uses Simplera Sync only

This compatibility is a significant clinical advantage. Patients on a Tandem, Insulet, or mylife system can use the G7 as their sensor regardless of pump choice – a level of flexibility not available with other CGM systems.

Features

Alarms and alerts

Customisable high and low alerts, urgent low alert, rapidly falling alert. The 12-hour grace period on wear also means no alarm at sensor end-of-life until the grace period expires – reducing disruption.

Follow and share

Dexcom Follow app allows family members, carers, and school staff to view real-time glucose data. Particularly valued in paediatric use and for independent young adults.

No separate transmitter

Unlike the G6, the G7 has an all-in-one design – the transmitter is built into the disposable sensor pod. This reduces device management complexity.

Optional calibration

The G7 does not require calibration, but does accept optional calibration entries. If used, calibration should be based on a properly performed finger prick blood glucose test – not on the CGM reading itself.

Receiver option

A standalone Dexcom receiver is available for users who prefer not to use a smartphone – including those without a compatible phone or those in environments where phone use is restricted.

Clinical evidence

  • Garg SK et al. (2022). Accuracy and Safety of Dexcom G7 Continuous Glucose Monitoring in Adults with Diabetes. Diabetes Technology and Therapeutics. n=316, 77,774 matched pairs. ±20/20 agreement 95.3% (arm), 93.2% (abdomen).
  • Dexcom G7 FDA clearance (December 2022). Adults and children 2 years and older.
  • G7 paediatric data. Available through FDA regulatory summary. MARD consistent with adult data.

From the GNL Podcast

Episode 37 of The Glucose Never Lies features a full conversation with Adam Dawes, Senior Medical Affairs Manager at Dexcom UK. The episode covers the G7 evidence base, AID integration, the clinical picture for different patient groups, and what makes the G7 stand apart in a rapidly changing CGM market. Listen on your usual podcast platform or on theglucoseneverlies.com.

GNL Podcast – Episode 37

Further information

For prescribing routes, patient access, and further clinical detail, contact Dexcom UK directly. Adam Dawes (Senior Medical Affairs Manager) is the primary contact for clinical enquiries: adam.dawes@dexcom.com.