What are the components of the Freestyle Libre (Flash Glucose Monitoring) system?

Medical Advisory BoardAll articles are reviewed for accuracy by our Medical Advisory Board
Educational purpose only • Exercise caution as content is pending human review
Article Review Status
Submitted
Under Review
Approved

Last updated: June 19, 2025View editorial policy

Personalize

Help us tailor your experience

Which best describes you? Your choice helps us use language that's most understandable for you.

From the Guidelines

The Freestyle Libre Flash Glucose Monitoring system consists of three main components: a small, round sensor, a handheld reader device or compatible smartphone app, and disposable sensor applicators. The sensor contains a thin, flexible filament that is inserted just under the skin to measure glucose levels in the interstitial fluid continuously for up to 14 days [no specific duration mentioned in 1]. The reader or smartphone app is used to scan the sensor to obtain current glucose readings, and an 8-hour history of glucose data can be captured and downloaded if the sensor is scanned at least every 8 h 1. Key features of the system include:

  • A small, round sensor applied to the back of the upper arm
  • A handheld reader device or compatible smartphone app
  • Disposable sensor applicators
  • Water-resistant sensor that can be worn while showering or swimming
  • No need for routine fingerstick calibrations, making it less invasive than traditional glucose monitoring 1. This system helps patients with diabetes better manage their condition by providing comprehensive glucose data that shows not just current levels but also how glucose changes throughout the day in response to food, medication, exercise, and other factors.

From the Research

Components of the Freestyle Libre System

The Freestyle Libre system consists of several components, including:

  • A sensor that is applied to the skin to measure glucose levels [(2,3,4,5,6)]
  • A reader or mobile phone that is used to scan the sensor and obtain glucose readings [(2,3,4,5,6)]
  • A factory-calibrated continuous 14-day glucose sensor 2

Key Features of the Freestyle Libre System

Some key features of the Freestyle Libre system include:

  • Continuous glucose monitoring for up to 14 days 2
  • Factory-calibrated sensor that does not require user calibration 2
  • Ability to scan the sensor with a reader or mobile phone to obtain glucose readings 3
  • Suitable for use in adults with type 1 diabetes [(2,4)]
  • Can be used in alternative sites, such as the upper arm, lower back, and anterior chest 6

Accuracy and Performance of the Freestyle Libre System

Studies have shown that the Freestyle Libre system has adequate accuracy during its entire lifetime, but is least accurate during its first and last days 2. The system has also been compared to other continuous glucose monitoring systems, such as the Dexcom G7, and has been shown to have lower mean absolute relative difference (MARD) values 4. Additionally, the system has been evaluated for use in client-owned cats with diabetes mellitus and has been shown to be easy to use and have good correlation with blood glucose measurements 5.

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

Have a follow-up question?

Our Medical A.I. is used by practicing medical doctors at top research institutions around the world. Ask any follow up question and get world-class guideline-backed answers instantly.