The Dexcom G7 sensor is a small, wearable continuous glucose monitor (CGM) that reads your blood sugar every 5 minutes for up to 10.5 days. Approved by the FDA in late 2022, it is 60% smaller than the previous Dexcom G6, more accurate, and faster to warm up. The G7 is designed for people with type 1 and type 2 diabetes, as well as gestational diabetes.
How the Dexcom G7 Sensor Works
The Dexcom G7 consists of a tiny filament that sits just under your skin (usually on the upper arm) and a small transmitter that broadcasts data by Bluetooth to your smartphone or receiver. Inside the filament is a glucose-oxidase enzyme that creates a small electrical current proportional to the glucose in your interstitial fluid — the fluid around your cells.
That current is measured every few seconds and averaged to produce a reading every 5 minutes. The result is a real-time blood sugar trend line you can watch on your phone along with high/low alerts, arrows showing direction of change, and shareable data for your healthcare team.
What Is New in the G7
- Smaller form factor: About the size of three stacked nickels, 60% smaller than the G6
- Faster warm-up: 30 minutes vs. 2 hours on the G6
- 10.5-day wear: Up from 10 days, with a 12-hour grace period
- Improved accuracy: MARD of 8.2% vs. 9.0% for the G6
- Direct phone integration: No separate transmitter; sensor and transmitter are one disposable unit
- Expanded compatibility: Works with Apple Watch and many automated insulin delivery systems
According to a 2022 accuracy study in Diabetes Technology & Therapeutics, the G7’s 8.2% MARD makes it one of the most accurate CGMs available.
Dexcom G7 vs. Other CGMs
| Feature | Dexcom G7 | Dexcom G6 | Abbott FreeStyle Libre 3 |
|---|---|---|---|
| Wear time | 10.5 days | 10 days | 14 days |
| Warm-up | 30 minutes | 2 hours | 1 hour |
| MARD | 8.2% | 9.0% | 7.9% |
| Reading frequency | Every 5 minutes | Every 5 minutes | Every 1 minute |
| Fingerstick required? | No | No | No |
| Approved age | 2 and older | 2 and older | 4 and older |
Accuracy in Real-World Use
A MARD of 8.2% means that on average, the G7 reading is within about 8% of a simultaneous laboratory reference value. Accuracy is slightly lower on the first day of wear and in low-glucose ranges (under 70 mg/dL), so some users still fingerstick to confirm hypoglycemia before treating.
Acetaminophen, hydroxyurea, and very high-dose vitamin C can interfere with G7 readings in some users. Heat, extreme cold, or vigorous compression (sleeping on the sensor) may cause temporary signal loss.
Who Should Use a Dexcom G7?
The FDA has cleared the G7 for:
- Type 1 diabetes (all ages 2+)
- Type 2 diabetes on insulin
- Type 2 diabetes not on insulin (covered by some plans)
- Gestational diabetes (the only CGM specifically FDA-approved for pregnancy)
People with prediabetes generally pay out of pocket, since most insurers do not cover CGM at that stage. Consumer-grade biosensors like Dexcom Stelo are often a better fit for non-diabetic monitoring. Learn more about A1C levels and prediabetes screening to see where you stand.
Cost and Insurance
Retail cost is roughly $120-180 per sensor without insurance, and users go through about 3 sensors per month. Most commercial insurance plans and Medicare cover G7 for people with diabetes who qualify by diagnosis. Dexcom offers a patient-assistance program and a cash-pay price through pharmacies for uncovered patients.
How to Insert and Use the G7
- Clean the back of your upper arm with an alcohol wipe and let it dry.
- Remove the sensor applicator cap, press it against your skin, and click the button. The insertion is nearly painless.
- Pair the sensor with the Dexcom G7 app on your smartphone.
- Wait 30 minutes for warm-up.
- Watch your glucose trend, set high/low alerts, and share with caregivers or your doctor.
Remove the sensor by peeling the adhesive patch. Apply a new sensor to the opposite arm to rotate sites.
Lifestyle and Diabetes Management
Continuous glucose monitors are a powerful tool but work best alongside diet, exercise, and sleep. Pair the G7 with a balanced eating plan — see our diet and nutrition resources — and regular follow-up with your healthcare team.
The Bottom Line
The Dexcom G7 sensor is a smaller, more accurate, and faster-warming continuous glucose monitor than its predecessor. It is FDA-approved for people with type 1, type 2, and gestational diabetes aged 2 and older, and it delivers glucose readings every 5 minutes for up to 10.5 days without fingerstick calibration. Talk to your doctor about whether the G7 is a fit for your treatment plan, and check with your insurer about coverage.
