Dexcom ONE+ is a continuous glucose monitoring system approved for type 1, type 2, and gestational diabetes in people aged 2 and older. It tracks glucose in real time via a small wearable sensor, giving users a clearer picture of their levels throughout the day.
Dexcom ONE+ shares sensor hardware with the G7 yet offers a more streamlined app experience. It measures interstitial glucose beneath the skin, skipping routine fingersticks. The sensor is waterproof, clinically accurate with single-digit MARD values, and compact at 24 x 27.3 x 4.6 mm. Real-world users praise its accuracy and ease of use.
Across accuracy, wearability, cost, and comparisons to Libre 2 and G7, Dexcom ONE+ consistently stands out as a capable, affordable CGM. This review covers everything you need to decide whether it is the right monitor for your diabetes management.
What Is Dexcom ONE+?
Dexcom ONE+ is a continuous glucose monitoring (CGM) system approved for type 1, type 2, and gestational diabetes in people aged 2 and older, covering a broad population of diabetes patients across multiple diagnosis categories.
In fact, it sends glucose readings every 5 minutes, 24/7, straight to a smartphone app or a dedicated receiver. No routine fingerstick checks required for daily use.
Dexcom ONE+ was reviewed through the investigational device exemption process and is FDA-cleared for diabetes management. Clearance covers type 1, type 2, and gestational diabetes in persons aged 2 and older.
How Does Dexcom ONE+ Differ From Other Dexcom Models?
Dexcom ONE+ and G7 share the same sensor hardware platform, but the G7 app is more feature-rich, offering rising and falling alerts, AI food logging, critical alerts, and insulin pump compatibility that ONE+ does not include.
Here’s the thing: ONE+ is not compatible with insulin pumps. That rules it out for users on closed-loop or hybrid closed-loop insulin delivery systems that require pump integration.
The ONE+ app also lacks rising and falling directional alerts, a 15-day sensor option, and critical alerts. You can’t switch between mmol/L and mg/dL units either, which limits flexibility compared to the G7 app.
Dexcom ONE+ vs G7 Feature Comparison:
| Feature | Dexcom ONE+ | Dexcom G7 |
|---|---|---|
| Sensor wear duration | 10 days | 10 days (15-day option available) |
| Rising and falling alerts | No | Yes |
| Critical alerts | No | Yes |
| Insulin pump compatibility | No | Yes |
| AI food logging | No | Yes |
| Unit switching (mmol/L / mg/dL) | No | Yes |
| Apple Watch support | No | Yes |
How Does Dexcom ONE+ Work?
The Dexcom ONE+ sensor measures glucose in the interstitial fluid just beneath the skin rather than directly in the bloodstream, using a tiny filament inserted through a one-push applicator designed for quick, low-discomfort application.
Readings are taken and transmitted automatically every 5 minutes around the clock. Data goes to the Dexcom ONE+ smartphone app or an optional receiver, giving you a continuous picture of glucose trends. Think of it this way: it’s like having a glucose check running silently in the background, all day, every day.
After applying the sensor, there’s a 30-minute warm-up period before readings begin. Each sensor lasts 10 days, with an additional 12-hour grace period before you need to replace it.
Getting Started with Dexcom ONE+:
- Insert the sensor using the one-push applicator on the back of the upper arm or abdomen.
- Wait 30 minutes for the system to initialise — no calibration fingerstick is required.
- Open the Dexcom ONE+ app on a compatible smartphone to begin receiving readings.
- Review automatic glucose readings delivered every 5 minutes, 24/7.
- Set personalised high and low glucose alert thresholds in the app.
- Replace the sensor after 10 days, using the 12-hour grace period for convenience.
What Is Continuous Glucose Monitoring (CGM) and Do You Still Need Fingersticks?
CGM technology differs from traditional fingerstick meters by measuring glucose in interstitial fluid under the skin rather than in blood, delivering continuous data instead of isolated point-in-time readings that only capture a single glucose snapshot.
The good news? Dexcom ONE+ is factory calibrated, so routine fingersticks aren’t required. But they’re still recommended when sensor readings don’t match how you feel.
Here’s why: glucose enters the bloodstream first and then diffuses into interstitial fluid. CGM readings can lag slightly behind fingerstick blood glucose values, particularly during rapid glucose changes.
What Are the Key Features of Dexcom ONE+?
The Dexcom ONE+ sensor is waterproof and can be submerged under 2.4 metres (7.9 ft) of water for up to 24 hours without failure when properly installed. Swimming and daily showering require no removal at all.
You can wear it on the back of the upper arm or on the abdomen. For children aged 2 to 6, the upper buttocks is an additional approved wear site.
What’s more, up to 10 followers, including caregivers, family members, or clinicians, can monitor a user’s glucose data remotely in real time. The free Dexcom Follow companion app powers this remote monitoring capability.
CGM data is automatically shared with healthcare professionals through Dexcom Clarity integration. This streamlines clinical reviews and helps providers track glucose patterns between appointments.
Key Features of Dexcom ONE+:
- Waterproof up to 2.4 metres for up to 24 hours
- Automatic glucose readings every 5 minutes, 24/7
- 30-minute warm-up with no calibration fingerstick required
- 10-day wear life with a 12-hour grace period
- Up to 10 remote followers via the free Dexcom Follow app
- Healthcare data sharing through Dexcom Clarity
- Customisable high and low glucose alerts with a Delay 1st Alert option
- Optional dedicated receiver with up to 7-day battery life
How Accurate Is the Dexcom ONE+ Sensor?
Dexcom rates ONE+ as among the most accurate CGMs available, on par with the G7, based on Dexcom Data on File 2023, with single-digit MARD values achieved for more than 70 percent of sensors tested.
Accuracy is slightly lower immediately after sensor insertion, during hypoglycemia, and during rapid glucose changes. Does that matter? In most cases, no. But it’s worth knowing these are the moments when interstitial fluid lag is most pronounced and readings may diverge from blood values.
How Small and Discreet Is the Dexcom ONE+ Wearable?
The Dexcom ONE+ sensor measures 24 x 27.3 x 4.6 mm, placing it among the smallest CGM sensors on the market and, alongside the G7, the smallest CGM sensor currently available in the Australian market.
A one-push applicator lets you apply the sensor quickly and with minimal discomfort. This reduces the barrier to self-insertion for new users and children who aren’t yet familiar with CGM devices.
What Is the Warm-Up Time and Grace Period?
After inserting a new sensor, users must wait 30 minutes for the system to initialise before glucose readings become available, and no calibration fingerstick is needed at any point during this warm-up window.
Once the standard 10-day wear period ends, the sensor provides an additional 12-hour grace period. So you don’t have to scramble to replace it at the exact moment it expires. Replace it when it’s actually convenient.
How Does the Dexcom ONE+ App Work?
The Dexcom ONE+ app shows real-time glucose values alongside directional trend arrows that indicate the speed and direction of glucose change, helping users anticipate highs and lows before they occur and act with greater confidence.
You can customise high and low glucose alerts to match your personal thresholds. Here is the kicker: a unique ‘Delay 1st Alert’ option postpones the first high alert after a meal, reducing alarm fatigue from predictable post-meal glucose spikes.
The app includes event logging for food, insulin, and exercise. You can correlate lifestyle factors with glucose patterns and share richer data with your healthcare team during clinical appointments.
For users without a compatible smartphone, Dexcom offers a dedicated receiver device. Its battery lasts up to 7 days on a single charge. The receiver displays glucose readings independently, no phone required.
What Do Real Dexcom ONE+ Reviews Say?
Real-world user reviews of Dexcom ONE+ are broadly positive, with users praising accuracy, ease of use, and alert setup, particularly among those switching from competitor devices like the FreeStyle Libre 2, where feature gaps were more noticeable.
Several users who switched from FreeStyle Libre 2 report preferring Dexcom ONE+ for its superior accuracy and insulin trend visibility. That trend visibility? It’s missing entirely on the Libre platform.
What Do Users Love About Dexcom ONE+?
Accurate readings are the most consistently praised aspect of Dexcom ONE+ across user reviews, with many describing high confidence in the glucose values displayed compared to their prior CGM devices and finger-check results.
Users specifically highlight directional trend arrows as a key advantage over FreeStyle Libre 2. The ability to see glucose trajectory helps users make better insulin dosing decisions in real time. Short answer: it’s the kind of visibility that changes how you manage your day.
Reviewers also note that setting up glucose alerts is straightforward and intuitive. This reduces the learning curve for new CGM users and helps people feel more in control of their diabetes management from day one.
What Users Consistently Praise About Dexcom ONE+:
- High confidence in glucose reading accuracy compared to prior CGM devices
- Directional trend arrows for more informed insulin dosing decisions
- Simple and intuitive alert setup with minimal learning curve
- Real-time trend visibility not available on FreeStyle Libre 2
- Ease of self-insertion using the one-push applicator
What Are the Most Common Complaints About Dexcom ONE+?
A frequently cited complaint is the absence of Apple Watch compatibility, with users reporting an error message when attempting to connect the ONE+ app to Apple Watch, a notable feature gap compared to more advanced CGM app ecosystems.
Unlike the G7 app, Dexcom ONE+ doesn’t offer rising or falling rate-of-change alerts or critical alerts. Pay attention to this: users on Focus or Do Not Disturb modes risk missing nighttime low glucose warnings entirely.
Users also report frustration that the app doesn’t allow switching between mmol/L and mg/dL. And there’s no custom glucose range settings or Dark Mode. For tech-oriented users, it can feel underdeveloped compared to competing platforms.
Common User Complaints About Dexcom ONE+:
- No Apple Watch compatibility
- No rising or falling rate-of-change alerts
- No critical alerts for nighttime hypoglycemia
- Cannot switch between mmol/L and mg/dL units
- No custom glucose range settings
- No Dark Mode in the app
How Does Dexcom ONE+ Compare to Libre 2 and Dexcom G7?
Users and reviewers consider Dexcom ONE+ more accurate than FreeStyle Libre 2 and praise its insulin trend arrows, while Libre 2 is generally cheaper but offers fewer real-time trend features according to consistent user feedback across review platforms.
Both Dexcom ONE+ and G7 use the same sensor hardware. But the G7 offers a more mature app. It includes rising and falling alerts, AI food logging, critical alerts, a 15-day sensor option, and insulin pump compatibility. Those are meaningful differences.
Despite Dexcom ONE+’s overall feature advantages, some users still prefer FreeStyle Libre 2’s notification system. Alert delivery experience is subjective. It’s a personally important factor in CGM device preference, and that’s worth respecting.
Dexcom ONE+ vs FreeStyle Libre 2 vs Dexcom G7:
| Feature | Dexcom ONE+ | FreeStyle Libre 2 | Dexcom G7 |
|---|---|---|---|
| Sensor wear duration | 10 days | 14 days | 10 days (15-day option) |
| Real-time trend arrows | Yes | No | Yes |
| Rising and falling alerts | No | No | Yes |
| Critical alerts | No | No | Yes |
| Insulin pump integration | No | No | Yes |
| Apple Watch support | No | No | Yes |
| Factory calibrated | Yes | Yes | Yes |
What Are the Limitations and Drawbacks of Dexcom ONE+?
Dexcom ONE+ cannot integrate with insulin pumps, ruling it out for people using or considering closed-loop automated insulin delivery systems that depend on a compatible CGM sensor to function correctly and safely.
The ONE+ app lacks critical alerts, rising and falling rate alerts, Apple Watch support, AI food logging, and Dark Mode. For example, if you’re a tech-oriented user expecting feature parity with the G7, these absences will frustrate you quickly.
Sensor accuracy can dip right after insertion, during hypoglycemia, and during rapid glucose fluctuations. Does that mean you need fingersticks all the time? No. But in these specific scenarios, confirming with a fingerstick blood glucose test is the smarter call.
Key Limitations of Dexcom ONE+:
- Not compatible with insulin pumps or closed-loop delivery systems
- No critical alerts for severe hypoglycemia
- No rising or falling rate-of-change alerts
- No Apple Watch support
- No AI food logging
- Cannot switch between mmol/L and mg/dL units
- No Dark Mode or custom glucose range settings in the app
- Accuracy may decrease immediately after insertion and during rapid glucose changes
Who Should Avoid Using Dexcom ONE+?
Dexcom ONE+ is not indicated for patients on dialysis treatment, a contraindication listed in clinical guidance that all prospective users and their healthcare providers should review and discuss before beginning use of the device.
People who rely on insulin pumps, particularly those using hybrid closed-loop systems, should consider the Dexcom G7 instead. To be clear, Dexcom ONE+ simply doesn’t have the pump integration capability those systems require to operate.
And if you depend on critical nighttime alerts, Apple Watch glucose notifications, or rate-of-change alarms? The G7 is the better fit. These features aren’t just limited on ONE+. They’re absent entirely.
Is Dexcom ONE+ FDA Approved and Clinically Proven?
Yes. Dexcom ONE+ was reviewed through the FDA’s investigational device exemption process and is cleared for diabetes management in type 1, type 2, and gestational diabetes for persons aged 2 and older across all approved indications.
A 2017 JAMA study by Beck RW showed CGM lowers HbA1c. A 2021 Diabetes Care study by Lind M demonstrated improved time in range. Both studies provide the clinical foundation supporting Dexcom ONE+ use in practice. That’s not marketing. That’s peer-reviewed evidence.
Clinical studies reported only mild adverse events including minor skin redness at the insertion site, adhesive skin irritation, and mild to moderate discomfort during removal. No serious adverse events were recorded in the clinical data.
How Much Does Dexcom ONE+ Cost?
In the UK, a single Dexcom ONE+ sensor retails at £35.00 excluding VAT, with a subscription model available that can save users up to 27 percent compared to purchasing sensors at the standard individual unit price.
In the UK, NHS funding is available for eligible type 2 diabetes patients. This funding can significantly reduce or eliminate the out-of-pocket cost of sensors for qualifying individuals. Worth checking before you pay full price.
In the US, you earn 200 reward points per sensor purchased through the Dexcom ONE+ Rewards program. Accumulate 1,000 points and you unlock a $40 (USD) voucher toward future purchases. So, it adds up over time.
Dexcom ONE+ Pricing and Savings Options:
| Purchase Option | Market | Detail |
|---|---|---|
| Standard single sensor | UK | £35.00 excluding VAT |
| Subscription plan | UK | Up to 27% saving vs standard price |
| NHS funding | UK | Available for eligible type 2 diabetes patients |
| Rewards program | US | 200 points per sensor; 1,000 points = $40 USD voucher |
| G’day Dexcom trial | Australia | Free trial program for new users via amsldiabetes.com.au |
Is Dexcom ONE+ Worth the Price?
Yes. At £35 per sensor in the UK, Dexcom ONE+ sits in the premium CGM tier, but for users who prioritise accuracy and trend visibility over cost, the clinical outcomes data and user reviews consistently support the investment in this system.
Bottom line: opting into the subscription plan saves up to 27 percent on sensors. That’s a meaningful reduction for long-term users who commit to consistent CGM use as part of their diabetes management routine.
Where Can You Buy Dexcom ONE+?
Dexcom ONE+ is available directly through dexcom.com globally, through amsldiabetes.com.au in Australia, and via healthcare professional prescription pathways in all supported markets where the device has received regulatory clearance.
In Australia, you can access Dexcom ONE+ through amsldiabetes.com.au. New users may be eligible for the G’day Dexcom trial program, which lets you try the system before committing to an ongoing purchase.
Is Dexcom ONE+ the Right CGM for You?
Yes. Dexcom ONE+ is well suited for people with type 1, type 2, or gestational diabetes aged 2 and older who want accurate, automatic glucose monitoring without routine fingersticks and do not require insulin pump integration as part of their therapy.
You’re prioritising accuracy and ease of use over advanced app features? ONE+ is a strong choice. But if you need pump compatibility, critical alerts, or Apple Watch support, the Dexcom G7 is the better fit.
For users currently on FreeStyle Libre 2 who want better accuracy and real-time trend arrows, Dexcom ONE+ represents a meaningful upgrade. Real-world switcher reviews confirm this improvement across multiple review platforms. And that’s about as close to a consensus as you’ll find in CGM communities.