- CGM provides real-time data on how your body responds to specific foods, exercise, and medication
- Dexcom Stelo is available over the counter — no prescription or diabetes diagnosis needed
- Dexcom G7 is a prescription CGM for patients who also manage diabetes or insulin resistance
- Your PEAK clinician and dietitian use CGM data to refine your nutrition plan and medication approach
Why CGM for Weight Loss
A continuous glucose monitor (CGM) is a small sensor — typically worn on the back of the upper arm — that measures your glucose levels throughout the day and sends the data to an app on your phone. Originally developed for diabetes management, CGMs have become a valuable tool in medical weight loss because they reveal how your body uniquely responds to food. CGM use for weight management in patients without diabetes is an emerging application supported by growing clinical experience, though it has not yet been evaluated in the same large-scale trials as CGM for diabetes management.
Two people can eat the same meal and have completely different glucose responses. A CGM makes that visible. It shows your clinician and dietitian which foods cause sharp glucose spikes (and the energy crashes and cravings that follow), which meals keep you stable, and how exercise, sleep, and stress influence your metabolism.
A CGM turns invisible metabolic patterns into actionable data your care team can use.
For patients on GLP-1 medications like Wegovy or Zepbound, CGM data is especially useful. These medications affect glucose regulation directly, and a CGM lets your clinician see exactly how well the medication is working and whether your dietary choices are supporting or undermining your treatment.
Dexcom Stelo
Dexcom Stelo is the first over-the-counter continuous glucose monitor cleared by the FDA (FDA cleared June 2024). It is designed for people who do not use insulin — including those focused on weight management, metabolic health, and general wellness. No prescription is required.
How it works
Stelo uses a small, disposable sensor that adheres to the back of your upper arm. The sensor has a tiny filament that sits just under the skin and measures glucose levels in interstitial fluid. Data is transmitted wirelessly to the Dexcom Stelo app on your smartphone, where you can see your current glucose level, trends over time, and how specific meals and activities affect your numbers.
Key specs
- Sensor wear time: Up to 15 days per sensor
- Warm-up time: 30 minutes after application
- Reading frequency: Glucose readings every 15 minutes
- Prescription required: No — available over the counter
- Compatibility: iPhone and Android via the Dexcom Stelo app
- Water resistant: Yes — can be worn while showering or swimming
Patients focused on weight loss and metabolic health who do not have diabetes or use insulin. Stelo is ideal for gaining short-term insight into how your body responds to food — most patients wear it for 2 to 4 weeks during active treatment.
Dexcom G7
Dexcom G7 is a prescription continuous glucose monitor designed for people with diabetes (type 1 or type 2). It is the most widely used real-time CGM system and is considered the clinical standard for glucose monitoring.
How it works
Like Stelo, the G7 uses a small adhesive sensor on the upper arm or abdomen. It continuously measures glucose and transmits data to the Dexcom G7 app or a compatible receiver. The key difference is that G7 provides real-time alerts — it can notify you when glucose is going too high or too low, which is critical for patients managing diabetes alongside their weight loss treatment.
Key specs
- Sensor wear time: Up to 10 days per sensor (or 15 days with the G7 15 Day sensor)
- Warm-up time: 30 minutes after application
- Reading frequency: Glucose readings every 5 minutes
- Prescription required: Yes — your PEAK clinician can prescribe this
- Real-time alerts: Customizable high and low glucose alerts
- Compatibility: iPhone, Android, Apple Watch, and compatible insulin pumps
- Water resistant: Yes
Patients who have type 2 diabetes or significant insulin resistance in addition to their weight loss goals. The G7's real-time alerts and more frequent readings provide the tighter monitoring that diabetes management requires.
Stelo vs G7: Side-by-side
| Dexcom Stelo | Dexcom G7 | |
|---|---|---|
| Prescription | No — over the counter | Yes — Rx required |
| Sensor wear time | Up to 15 days | Up to 10 or 15 days |
| Warm-up | 30 minutes | 30 minutes |
| Reading frequency | Every 15 minutes | Every 5 minutes |
| Real-time alerts | No | Yes — high/low alerts |
| Intended for | Non-insulin users, wellness, weight loss | Diabetes (type 1 & type 2) |
| Insurance coverage | Generally not covered (cash-pay) | Covered by most plans for diabetes |
Your PEAK clinician will recommend the right device based on your medical history, whether you have a diabetes diagnosis, and your treatment goals. Many weight loss patients without diabetes start with Stelo for a focused monitoring window during early treatment.
How We Use CGM at PEAK
At PEAK, CGM is not a standalone product — it is integrated into your clinical weight loss program. Your clinician and registered dietitian review your glucose data together and use it to make concrete adjustments to your treatment plan.
What your care team looks for
- Post-meal glucose spikes: Which foods cause sharp rises (and the energy crashes and cravings that follow), so your dietitian can suggest alternatives
- Glucose stability patterns: How steady your levels are throughout the day — stable glucose correlates with reduced cravings and better energy
- Medication response: How well your GLP-1 medication is improving glucose regulation, which helps your clinician make dosing decisions
- Exercise impact: How different types of physical activity affect your glucose, helping optimize your activity plan
- Fasting and meal timing: Whether your eating schedule supports or disrupts metabolic stability
Most patients wear a CGM for 2 to 4 weeks during the early phase of treatment. This provides enough data for your care team to identify your key patterns. Some patients choose to continue longer for ongoing accountability, and your clinician can recommend additional monitoring periods at dose changes or plateaus.
CGM data turns your dietitian visits from subjective conversations into evidence-based sessions. Instead of asking "how has your eating been?", your dietitian can say "I can see that your Tuesday lunch caused a significant spike — let's look at what you ate and find a better option." That specificity makes the guidance more actionable and the results more durable.
Common Questions
Do I need a prescription for a CGM?
It depends on the device. Dexcom Stelo is available over the counter — you can purchase it directly without a prescription. Dexcom G7 requires a prescription, which your PEAK clinician can provide if it is clinically appropriate for your situation.
Does insurance cover CGM for weight loss?
Most insurance plans cover CGM only for diabetes management, not for weight loss alone. Dexcom Stelo is designed as a cash-pay option for patients who want glucose data without a diabetes diagnosis. If you do have a diabetes diagnosis, the Dexcom G7 may be covered by your insurance. Your PEAK team can help determine the best option.
How long do I need to wear a CGM?
Most patients benefit from 2 to 4 weeks of continuous monitoring during active treatment. That is usually enough data for your clinician and dietitian to identify meaningful patterns. Your care team may recommend additional monitoring periods at dose changes or if you hit a weight loss plateau.
Does it hurt?
The sensor application involves a very brief pinch — most patients describe it as less noticeable than a standard blood draw. Once the sensor is in place, you should not feel it during normal daily activities, exercise, or sleep.
Can I shower and exercise with it on?
Yes. Both the Stelo and G7 are water resistant. You can shower, swim, and exercise while wearing the sensor. The adhesive is designed to stay in place throughout the full wear period.
References
- FDA 510(k) clearance for Dexcom Stelo (K233979). U.S. Food & Drug Administration. June 2024.
- Dexcom G7 Continuous Glucose Monitoring System prescribing information. Dexcom, Inc.
- Hall H, et al. Glucotypes reveal new patterns of glucose dysregulation. PLoS Biol. 2018;16(7):e2005143.