Your Guide to CGM Supplies: Sensors, Transmitters & Accessories Explained
Managing diabetes has come a long way from daily finger pricks and guesswork. Continuous Glucose Monitors (CGMs) have changed the game, helping people track blood sugar levels in real time and live with more freedom and confidence.
But if you’re new to CGMs, it can be confusing to understand what all the different parts do: sensors, transmitters, readers, accessories, and which brand is right for you.
That’s where CityDME comes in. As a trusted provider of diabetes management supplies in New York, we help patients get started with top-rated CGMs like Dexcom and FreeStyle Libre, including insurance-covered supplies, sensors, and accessories.
Let’s go over what each part does and how they work together to help you stay in control.
What Is a Continuous Glucose Monitor (CGM)?
A Continuous Glucose Monitor is a small, wearable device that automatically measures your glucose (sugar) levels day and night. Instead of pricking your finger several times a day, a CGM uses a tiny sensor inserted just under your skin to measure glucose in the interstitial fluid, the fluid between your cells.
These readings update every few minutes and appear on your smartphone or a receiver, helping you track trends and get alerts if your glucose levels go too high or too low.
CGMs can help you:
- Catch blood sugar changes early
- Help identify glucose patterns and trends
- Make better food and insulin decisions
- Improve A1C results with more consistent monitoring
- Sleep better knowing you’ll get alerts overnight
- Reduce fingerstick testing
The Main Parts of a CGM System
All CGM systems have three key components that work together:
- Sensor – a small, flexible piece that sits just under the skin and measures glucose levels.
- Transmitter – sends the readings from the sensor to your phone or receiver.
-
Receiver or Smartphone App – displays your glucose levels, trends, and alerts.
You can also add optional accessories to help your CGM stay in place and last longer, such as adhesive patches or armbands, especially helpful during humid New York summers.
CGM Components Explained
1. The Sensor: The Heart of the CGM
The sensor continuously measures glucose levels in your interstitial fluid. It’s placed under the skin (commonly on the upper arm or abdomen) using a simple applicator.
Quick facts:
- Dexcom G7 sensors last up to 10 days before replacement.
- FreeStyle Libre 3 Plus sensors typically last 15 days.
- After insertion, most CGMs require a warm-up period, usually 30 to 60 minutes, before readings start displaying.
Because readings come from interstitial fluid, not directly from the bloodstream, there’s a short delay (about 5–10 minutes) between CGM data and fingerstick glucose readings.
CityDME Tip: Always double-check your glucose with a traditional meter if symptoms don’t match your CGM reading, as recommended by both Dexcom and Cleveland Clinic.
2. The Transmitter: Sending the Data
The transmitter sends your sensor’s glucose readings to your receiver or smartphone.
- Dexcom G6: Has a separate, reusable transmitter that lasts around 3 months.
- Dexcom G7: Integrates the transmitter into the sensor for a smaller, simpler design.
- FreeStyle Libre 3 Plus: Has a built-in transmitter inside the sensor — no separate part to attach or charge.
Keep your transmitter area clean and dry, and store spare sensors or transmitters in a cool, dry place.
3. The Receiver or Smartphone App
Depending on your system, you’ll either use a dedicated receiver or your smartphone to view your data.
- Dexcom app: Displays glucose trends every 5 minutes, customizable alerts, and Apple Watch compatibility.
-
LibreLink app: Scans your sensor or automatically updates readings, depending on model.
Both systems let you share data with caregivers or healthcare professionals, helping you and your care team manage diabetes more effectively.
4. Helpful Accessories to Improve Comfort
Accessories can make a big difference in comfort and reliability, especially for active users or warm weather.
Popular CGM accessories include:
- Adhesive patches or covers: Help sensors stay in place during workouts or swimming.
- Skin-prep wipes: Create a protective barrier for sensitive skin and improve adhesion.
-
Armbands or fabric sleeves: Add an extra layer of protection and reduce snags.
Most CGMs are water-resistant (for example, up to 3 feet for 30 minutes in Libre sensors), but they should not be submerged beyond the manufacturer’s recommendations.
Dexcom VS. FreeStyle Libre: Key Differences
|
Feature |
Dexcom G6/Dexcom G7 |
FreeStyle Libre 2 Plus/FreeStyle Libre 3 Plus |
|
Sensor life |
Up to 10 days |
Up to 15 days |
|
Transmitter |
Separate (G6) or built-in (G7) |
Built-in |
|
Warm-up time |
~30 minutes |
~1 hour |
|
Real-time alerts |
Customizable |
Available in Libre 2 Plus & 3 Plus |
|
App integration |
Dexcom app + Apple Watch |
LibreLink app |
|
Best for |
Users who want more alerts and detailed data |
Users who want simplicity and more cost-effective tracking |
Both systems are FDA-cleared, accurate, and designed for ease of use. The right choice depends on your doctor’s recommendations, lifestyle, and insurance coverage.
Explore Continuous Glucose Monitors →
Tips for Choosing the Right CGM
If you’re getting a CGM for the first time, consider these tips:
- Check your insurance coverage. CityDME can verify eligibility for Dexcom and Libre systems.
- Think about your daily habits. If you’re tech-savvy and want detailed alerts, Dexcom may fit you best. If you prefer simplicity, Libre might be perfect.
- Ask your doctor. They can recommend which model aligns with your diabetes management plan.
- Consider data-sharing features. Real-time alerts and app integration can help your care team monitor progress.
Fill Out Our Patient Form to Check Your Eligibility
How to Order CGM Supplies from CityDME
Ordering your supplies through CityDME is simple and stress-free:
- Fill out our Patient Form or find the device you need and click on the “Insurance Purchase Request” button.
- We verify your insurance and work with your provider to handle documentation.
- We deliver your supplies quickly — discreetly and directly to your New York home.
CityDME proudly serves patients throughout Brooklyn, Queens, the Bronx, and beyond, providing top-rated medical supplies with fast, reliable service.
Check Your Insurance Eligibility Today
Frequently Asked Questions (FAQ) About CGMs
Q: How often do I replace my CGM sensor?
Most sensors last 10–14 days, depending on the brand and model.
Q: Are CGMs covered by insurance?
Yes. Most major insurance plans, including Medicaid and Medicare, cover CGMs for people with diabetes when prescribed.
Q: Can I swim or shower with a CGM?
Yes, CGMs are water-resistant within limits (e.g., up to 3 feet for 30 minutes). Always follow your device’s manual for exact details.
Q: Do I still need fingersticks?
You might occasionally need to use a glucose meter if your CGM reading doesn’t match how you feel.
Q: What should I do if my sensor comes loose?
Use an adhesive patch or contact CityDME for guidance on replacements.
Simplify Diabetes Care with CityDME
Understanding your CGM system is the first step toward taking control of your diabetes care. From sensors and transmitters to accessories and support, having the right tools makes all the difference.
At CityDME, we’re proud to help New Yorkers access trusted diabetes management brands like Dexcom and FreeStyle Libre, along with all the supplies you need, delivered right to your door!
