Setting Expectations for Glucose Readings

Setting Expectations for CGM Glucose Readings

A Continuous Glucose Monitor (CGM) sensor is a great tool to track how your blood sugar fluctuates throughout the day. Here are a few points to keep in mind when using your CGM sensor:

Ideal blood glucose levels for non-diabetics

AgelessRx recommends non-diabetic patients aim for a range between 75-125 mg/dL. 70 mg/dL to 80 mg/dL is considered an ideal fasting sugar level, and post-meal glucose levels should not spike sugar higher than 125mg/dl.

However, this isn’t a strict rule. Some people cannot tolerate these lower levels and need to work on bringing them down into this range over time. On the other hand, there are some people who are “fat adapted” and thrive on lower levels of blood glucose.

Please consult with your PCP for more personalized expectations of your ideal blood glucose levels.

There is a margin of error of about 10-20% for all CGM sensors.

There are some limitations on the accuracy of readings from your CGM sensor. This is the case for all CGM sensors on the market, regardless of brand.

We currently offer the FreeStyle Libre Version 2 sensor, which has significantly improved accuracy compared to previous versions and other brands.

All glucose reading tools have some margin of error. Even a finger stick reading has a margin of error of 10-20%, depending on the device. It is important to take this into account when reviewing your blood glucose levels.

Blood sugar readings from a CGM sensor are delayed by roughly 15 minutes compared to blood sugar readings from a blood glucose meter (finger prick).

If you take your readings from a CGM sensor and blood glucose meter at the same time, especially after eating food, you may notice different blood glucose levels.

This is because glucose circulates the body through the blood first, then eventually diffuses out into the interstitial fluid – a thin layer of fluid that surrounds your tissue cells and rests right under the skin but above your blood vessels.

CGM sensors measure blood sugar in the interstitial fluid, while blood glucose meters measure glucose from your blood vessels.

Because of this, you can expect a bit of a lag with readings from your CGM sensor, but just by about 15 minutes.

If you have any doubts about your CGM sensor’s readings, double check with a blood glucose meter.

A CGM sensor can be a great tool to check your blood sugar throughout the day. However, it’s not a bad idea to double check with a blood glucose meter, especially if you have doubts about your blood sugar readings from the CGM sensor.

Even a blood glucose meter can be inaccurate, depending on a variety of factors. For more information, read more about blood glucose measuring devices and guidelines on the FDA’s website.

If you have any questions about your CGM sensor, please feel free to contact the AgelessRx care team via email at or through the AgelessRx Customer Portal.