Continuous Glucose Monitors (CGMs) are revolutionizing diabetes management, offering real-time insights into blood sugar levels and freeing users from the inconvenience of fingersticks. If you’re considering a CGM or already using one, you might be wondering, how long can you wear a CGM? This is a common concern among users who want to make the most of their devices without compromising accuracy or safety.
In this article, we’ll answer this question in detail, addressing how sensor life works and providing practical tips to maximize the longevity and effectiveness of your CGM.
What Is a CGM, and Why Is Sensor Life Important?

A CGM, or Continuous Glucose Monitor, is a small device that tracks your blood sugar levels throughout the day and night. It consists of a tiny sensor inserted under the skin, a transmitter that sends glucose readings to a display device (like your phone or a receiver), and sometimes an adhesive patch to secure it.
The sensor has a specific lifespan, typically lasting anywhere from 7 to 14 days depending on the brand and model. After this period, the sensor must be replaced. Understanding how long you can wear your CGM sensor is crucial because it affects accuracy, cost, and the convenience of your diabetes management.
CGM Lifespan by Brand
Different CGMs have different sensor lifespans, and knowing the details of your specific device is key. Here’s an overview of some popular CGM systems and how long their sensors typically last:
- Dexcom G6: 10 days
- Freestyle Libre 2: 14 days
- Medtronic Guardian Sensor 3: 7 days
Each manufacturer designs their sensors with a specific duration in mind, balancing performance and safety. While it might be tempting to extend the life of a sensor beyond its recommended timeframe, doing so could compromise its accuracy and reliability.
Why Does Sensor Life Have a Limit?
You might wonder why CGM sensors can’t last indefinitely. Several factors contribute to their limited lifespan:
- Enzyme Degradation: CGM sensors use an enzyme to measure glucose levels in the interstitial fluid. Over time, this enzyme naturally degrades, reducing the sensor’s ability to provide accurate readings.
- Adhesive Wear and Tear: The adhesive securing the sensor to your skin can weaken over time, especially with exposure to sweat, water, and movement.
- Skin Irritation: Prolonged use of a sensor in one spot may cause irritation, redness, or even infection, making it necessary to remove and replace the sensor.
- Technology Calibration: Some CGMs rely on specific calibration periods to maintain accuracy. Extending wear beyond the recommended time frame can result in unreliable data.
Can You Extend the Life of a CGM Sensor?
It is possible to extend the life of some CGM sensors, but it’s not always advisable. For example, some users have reported resetting their sensors or using adhesive reinforcements to prolong wear. However, extending the life of a sensor could:
- Lead to inaccurate readings, which might affect your diabetes management.
- Void the manufacturer’s warranty or support if issues arise.
- Increase the risk of skin irritation or infection.
If you choose to extend a sensor’s life, it’s crucial to monitor its performance closely and replace it at the first sign of inaccuracy or discomfort.
Practical Tips to Maximize Sensor Life Within the Recommended Period
While extending sensor life beyond the recommended period isn’t always safe, you can take steps to maximize its effectiveness during its intended use. Here are some tips:
- Clean the Application Site: Before applying the sensor, clean the skin thoroughly with an alcohol wipe to remove oils, dirt, and bacteria.
- Use Skin Barriers: If you have sensitive skin, consider using a skin barrier wipe to protect your skin from adhesive irritation.
- Reinforce the Adhesive: Use medical-grade adhesive patches or tapes to secure the sensor, especially if you’re active or exposed to water.
- Avoid Excessive Water Exposure: While most CGMs are water-resistant, prolonged exposure to water can weaken the adhesive.
- Monitor Placement: Avoid placing the sensor on areas where it’s likely to be disturbed by clothing, belts, or physical activity.
Signs That It’s Time to Replace Your Sensor

Even if your sensor hasn’t reached the end of its recommended lifespan, certain signs may indicate it’s time for a replacement:
- Erratic Readings: If your glucose levels are fluctuating unusually or seem inaccurate, the sensor may no longer be functioning properly.
- Skin Discomfort: Redness, itching, or swelling around the sensor site could indicate irritation or infection.
- Adhesive Issues: If the sensor becomes loose or falls off, it’s time to replace it to ensure accurate readings.
Paying attention to these signs will help you maintain optimal performance and avoid complications.
The Role of Calibration in Sensor Longevity
Some CGMs, like the Medtronic Guardian Sensor 3, require periodic calibration using fingerstick tests. Calibration helps ensure accurate readings, but it becomes less effective as the sensor nears the end of its lifespan. If you notice that calibrations are becoming unreliable or frequent, it’s a sign that the sensor needs replacement.
On the other hand, many modern CGMs, like the Dexcom G6 and Freestyle Libre 2, are factory-calibrated and don’t require manual adjustments. These systems are designed to provide consistent accuracy within their recommended wear period.
Insurance and Cost Considerations
For many users, the cost of CGM sensors is a major factor in determining how long to wear them. While extending sensor life might seem like a cost-saving measure, it can lead to complications that outweigh the benefits.
Fortunately, most insurance plans cover CGM systems and their supplies, especially for individuals with diabetes. If you’re concerned about costs, speak with your healthcare provider or insurance company to explore coverage options. Some manufacturers also offer discount programs or patient assistance for those without insurance.
Planning Ahead for Sensor Changes
To avoid interruptions in your diabetes management, plan ahead for sensor replacements. Keep track of when your current sensor will expire and have a replacement ready. Many CGMs have companion apps that send reminders when it’s time to replace your sensor, making it easier to stay on schedule.
Additionally, talk to your healthcare provider about how to optimize your CGM use. They can provide guidance on proper placement, troubleshooting issues, and interpreting glucose data to improve your overall health.
Final Thoughts
So, how long can you wear a CGM? The answer depends on the specific device you’re using, but most CGMs are designed to function optimally for 7 to 14 days. By following the manufacturer’s guidelines, practicing good skin care, and monitoring your sensor’s performance, you can ensure accurate and reliable readings throughout its lifespan.
While it may be tempting to stretch a sensor beyond its intended use, the risks often outweigh the rewards. Instead, focus on maximizing your CGM’s performance within its recommended timeframe. This will not only protect your health but also ensure the data you rely on for diabetes management remains accurate and actionable.
Your CGM is a powerful tool that can transform the way you manage your blood sugar. By understanding sensor life and how to make the most of it, you can enjoy the benefits of real-time glucose monitoring without letting sensor limitations hold you back.
How Aptiva Medical Can Help You
At Aptiva Medical, we make managing your CGM sensor life simple. From choosing the right device to navigating replacements and adhesive issues, our team provides expert guidance and top-tier products to support your diabetes management journey.
With personalized care and resources, we’ll help you maximize your Continuous Glucose Monitoring system and stay on track with your health goals. Take control of your glucose monitoring—reach out to Aptiva Medical today for reliable support every step of the way.