The G6, G7, and Stelo explained — how they work, which one is right for you, and how to get the most out of whichever you're wearing.
Device specifications change frequently — always verify current information directly with the manufacturer before making any decisions. Full disclaimer.
New to CGM? Start here.
A CGM is a small wearable sensor that measures your glucose levels automatically, every five minutes, around the clock — no fingersticks required. It sends those readings wirelessly to your smartphone or receiver, and alerts you when your glucose is trending high or low. Dexcom makes three products: the G6, G7, and Stelo.
The Dexcom FamilyThe G7 combines sensor and transmitter into a single small unit. No separate transmitter to charge or keep track of — the whole thing comes off after 10 days.
After inserting a new sensor, the G7 is ready in just 30 minutes. A huge improvement over the G6's 2-hour warmup — and you can start it right before bed.
The G7 is the first and only CGM that sends readings directly to Apple Watch, without needing your phone nearby.
Set high and low alerts, urgency low alerts, and rise/fall rate alerts. All can be customized, silenced, or set to vibrate only.
Arden put a new sensor on while the old one was still running. When she took the old one off, the new one just popped on and read exactly where the other one was. I love it — everyone should try this if they can.
— Scott Benner, Juicebox Podcast Episode #954 · juiceboxpodcast.com/episodes/jbp954The G6 uses a separate transmitter that clips into the sensor and lasts 90 days. Sensors are replaced every 10 days; the transmitter is reused until its battery runs out.
Fully customizable high, low, and rate-of-change alerts. Includes a fixed Urgent Low alarm that triggers at 55 mg/dL and cannot be turned off.
The G6 integrates with Omnipod 5, Tandem Control-IQ, and other AID systems. It is still widely prescribed and fully supported.
Share data with up to 10 followers via the Dexcom Follow app. Data also syncs automatically to Dexcom Clarity for clinical review.
The G6 is still a workhorse — especially for anyone on an AID system that requires it. Know your transmitter's battery life and plan your sensor changes around it.
— Juicebox Podcast Community Wisdom · juiceboxpodcast.comNo prescription or doctor visit required. Available at pharmacies and stelo.com. FSA/HSA eligible. Not typically covered by insurance.
Stelo sensors last up to 15 days — the longest of any Dexcom product. Note: about 20% of sensors may not reach the full 15 days.
Stelo does not alert you to high or low glucose. It's a trend-tracking tool, not a safety device. Not appropriate for anyone on insulin or prone to hypoglycemia.
Designed for adults with Type 2 diabetes who don't use insulin, prediabetes, or people without diabetes who want to understand how food and activity affect glucose.
Stelo is built on the same sensor technology as the G7 — just without the alerts, alarms, or AID integration. It's a powerful awareness tool for the right person.
— Stelo by Dexcom · stelo.com/how-it-works| Feature | G6 | G7 | Stelo |
|---|---|---|---|
| Prescription required | Yes | Yes | No |
| Age range | 2+ | 2+ | 18+ (non-insulin) |
| Wear time | 10 days | 10 days (15 days available) | Up to 15 days |
| Warmup time | 2 hours | 30 minutes | 30 minutes |
| Design | Sensor + separate transmitter | All-in-one | All-in-one |
| High/low alerts | Yes | Yes | No |
| AID system integration | Yes | Yes | No |
| Apple Watch direct | No | Yes | No |
| Dexcom Follow sharing | Yes | Yes | No |
| Insurance coverage | Typically yes | Typically yes | No (FSA/HSA ok) |
Patient is on MDI or pump therapy, needs AID integration, or values shorter warmup and single-piece convenience. First-line for most T1D patients.
Patient is on an AID system requiring G6 compatibility, or has established G6 insurance coverage not yet extended to G7. Still fully supported.
Patient is T2D not on insulin, prediabetic, or motivated for lifestyle tracking. No prescription needed — direct patient to stelo.com or pharmacy.
G6/G7: Dexcom Clarity for clinical portal. Dexcom Follow for caregivers. Glooko and Tidepool also supported. Stelo has no data sharing options.
Wearing a Dexcom is the easy part. Getting accurate, consistent readings and using the data well is where the real learning happens. These are the habits and techniques that make the biggest difference.
Sensor PlacementThe G7's FDA-indicated wear site for ages 2 and older. Consistent, out of the way, and comfortable for most people. Less prone to compression lows than the abdomen.
The G6's primary indicated wear site. Pinch up skin and insert at a low angle. Avoid waistband areas and sites with scar tissue or bruising.
Wearing in the same spot repeatedly causes buildup of scar tissue, which reduces accuracy. Rotate systematically — think of your body as a clock face and move around it.
Readings are transmitted to your phone via Bluetooth. Stay within 20 feet (unobstructed) for consistent signal. The G7 stores 24 hours of data locally if you go out of range.
Start your new sensor while the old one is still running. Wear both briefly — then when you pull the old one, the new one is already warmed up and reading. No gap in data. The G7's 30-minute warmup makes this especially easy.
— Scott Benner, Juicebox Podcast Episode #954 · juiceboxpodcast.com/episodes/jbp954Glucose is stable — changing less than 1 mg/dL per minute. The number you see is a good representation of where you are.
Rising 1–2 mg/dL per minute. Factor this into your bolus decision — you're heading higher.
Rising more than 2 mg/dL per minute. Act now — your reading will be significantly higher in 15 minutes.
Falling 1–2 mg/dL per minute. If you're already near 80 and heading down with a diagonal arrow, it's time to treat or cut back on insulin.
Pull the Clarity report at each visit. Focus on: Time in Range (70–180 mg/dL), time below range (<70 and <54), and average glucose. A 10% TIR improvement = ~2.4 hrs/day in range.
If patients are silencing or ignoring alerts, help them reconfigure. Fewer, more meaningful alerts are better than many that train patients to ignore them. High alerts set too low are a common culprit.
Teach patients to factor trend arrows into dosing decisions, not just the number. A reading of 140 ↑↑ is a very different situation than 140 →. ADCES offers trend arrow dosing guidance.
Ensure school nurses, partners, and parents are set up on Dexcom Follow with appropriate alert thresholds. This is especially important for pediatric patients and college students managing independently for the first time.
For people who want to understand the science behind what they're wearing — and clinicians who need to speak to it confidently with patients.
AccuracyCGM accuracy is expressed as MARD — Mean Absolute Relative Difference. Lower MARD = better accuracy. A MARD of 8% means the sensor reading is within 8% of a gold-standard blood glucose reading on average.
Per Garg et al. (Diabetes Technology & Therapeutics, 2022): G7 MARD is 8.2% on the arm and 9.1% on the abdomen — among the most accurate CGMs available. The 15-day G7 achieved a MARD of 8.0% per a 2025 multicenter study presented at ATTD.
Stelo's accuracy is expressed differently by Dexcom — 93% accuracy compared to a gold-standard lab test. Built on the same sensor technology as the G7.
CGMs measure glucose in interstitial fluid (the fluid between cells), not blood directly. This creates a 5–15 minute lag compared to a fingerstick. The trend arrow compensates for this by showing direction of travel.
Both G6 and G7 are factory calibrated — no fingerstick calibration required. You can still calibrate manually if a reading seems off, but it's not routine.
| AID System | G6 Compatible | G7 Compatible |
|---|---|---|
| Omnipod 5 | Yes | Yes (iPhone nationwide) |
| Tandem Control-IQ (t:slim X2 / Mobi) | Yes | Yes |
| Medtronic 780G | No | No (uses Medtronic CGM) |
| Beta Bionics iLet | Yes | Yes |
| Tidepool Loop | Yes | Yes |
| Stelo | No AID integration — not for insulin users | |
Key clinical considerations for patients wearing Dexcom CGM, organized for use at any visit type.
G7 MARD: 8.2% (Dexcom clinical data). Among the most accurate CGMs available. Factory calibrated — routine fingerstick calibration not required. Fingerstick still indicated if symptoms don't match readings.
CGM measures interstitial glucose, not blood glucose — a 5–15 min physiological lag exists. Clinically significant during rapid glucose changes. Teach patients to use trend arrows for decisions during rising/falling glucose.
Pull Dexcom Clarity at every visit. Focus on TIR (target 70%), Time Below Range (<70 mg/dL, target <4%), and AGP pattern. Clarity integrates directly into G7 app — no separate login required for patients.
G6 and G7 both integrate with Omnipod 5, Tandem Control-IQ, iLet, and Tidepool Loop. Confirm correct sensor model for patient's pump. Stelo has no AID or clinical integration.
OTC. For adults 18+ not on insulin. No alerts, no sharing, no AID integration. Appropriate for T2D lifestyle tracking, prediabetes, or non-diabetic glucose awareness. Do not recommend for patients using insulin of any kind.
FDA cleared 2025. Same accuracy, integrations, and app as standard G7. Two sensor changes/month vs. three. Reduces patient burden and adhesive exposure. About 20% of sensors may not reach full 15 days.