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The NDSS is administered by Diabetes Australia
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Flash glucose monitoring fact sheet

PDF coverThis fact sheet is available in two formats.

You can download and print out the PDF version.

Or you can read it as a website page below.

Flash glucose monitoring (Flash GM) is a sensor technology that can help you measure your glucose levels without pricking your finger. Your diabetes health care team can provide you with more information and advice about Flash GM.

Regular (finger prick) blood glucose monitoring can help you track and monitor the effects on your blood glucose levels caused by food, exercise, medication, hormones and illness.

The result indicates when to act if blood glucose levels are outside of your target range. It also helps to identify trends or changes in blood glucose levels that you may wish to share with your diabetes health care team. Flash glucose monitoring continually measures glucose levels throughout the day and night, and therefore gives much more information than finger prick blood glucose monitoring. Flash GM provides a more in-depth understanding of glucose patterns and variability to help you make decisions about managing your diabetes.

A Flash GM device has no alarms—depending on the person’s individual needs this may be an advantage or a disadvantage.

How does Flash GM work?

Flash GM devices are small wearable sensors that measure glucose levels throughout the day and night. A reader or a smart phone or smart device (with the FreeStyle LibreLink app) is scanned over the sensor to see the current glucose level. When scanned, the reader shows arrows. This indicates whether glucose levels are rising, falling or steady. It also shows the previous eight hours of glucose data. The graphs on the Flash GM reader can be reviewed to look for patterns and trends in blood glucose levels.

Flash GM main parts

The only Flash GM device currently available in Australia is the FreeStyle Libre. This device has two main parts:

  1. The sensor sits on the skin (on the back of the arm) with a small electrode inserted just under the It measures the level of glucose in the interstitial fluid (the fluid between your cells). A new sensor needs to be inserted every 14 days.
  2. The reader (when sensor is scanned) allows you to view your glucose data including a current glucose reading, a graph of the last 8-hours of glucose readings, and a trend The reader may be either a FreeStyle Libre reader handheld device (which is also a blood glucose and blood ketone meter) or an app on a compatible smartphone or smart device. The reader also stores glucose data, which can be uploaded for you and your diabetes health care team to review to help make decisions about changes to insulin doses or insulin pump settings.

With Flash GM there is no transmitter, you scan sensor to read. The sensor should be located on the upper arm.

Flash GM parts as described in text above.

Why use Flash GM?

Flash GM has a number of benefits:

  • 24/7 readings. Flash GM allows you to view the changes to your glucose levels across the day, rather than just at a single point in time. Flash GM graphs may help you and your diabetes health care team learn how different things, such as food and physical activity, affect your glucose levels. Reviewing these graphs for patterns may help you balance your diet, physical activity and insulin doses. Data can only be seen if there is regular scanning of the sensor. To view a full day of glucose levels you need to scan at least every 8 hours.
  • Trend arrows. As well as showing glucose levels at any point in time, Flash GM shows whether glucose levels are rising, falling or stable and how quickly they are changing. This allows you to respond to rising or falling glucose levels before they are out of range.
  • Overnight monitoring. Flash GM devices measure glucose levels throughout the night without the need to wake up and do finger prick blood glucose checks. On waking up, you can scan and view your overnight glucose data (this may include any overnight hypos as these devices do not alarm to alert you of low glucose levels). To view a full day of glucose levels you need to scan at least every 8 hours.
  • Reduced need for finger prick checks. Flash GM does not completely replace the need for finger prick blood glucose checks, but it does reduce the number needed. The device doesn’t need calibrating; however, a finger prick blood glucose reading is needed when:
    • glucose levels change rapidly
    • to confirm hypoglycaemia
    • when symptoms don’t match the sensor reading
    • when adjusting insulin doses including before having an insulin correction dose.
  • An easier way to monitor. Flash GM makes it much easier to check glucose levels, particularly those who might find finger prick blood glucose checks difficult to do. It is also easier for carers, particularly for those in childcare, school or an aged care facility.
  • Peace of mind. Being able to easily check glucose levels at any time can provide reassurance and reduce anxiety.
  • Data sharing. The Freestyle Libre, has the option of sharing glucose data with up to 20 other people via the FreeStyle Libre app on their smartphone or smart device. This can be particularly useful if you are a parent, carer of a young child, or a carer or family member of an older person who is living alone, as it allows you to monitor their glucose levels even when you are not with them. Data can also be downloaded to share with their diabetes health care team.
  • Reduced alarm fatigue. While Flash GM doesn’t have the automated alarms available with continuous glucose monitoring (CGM), this can be a benefit for some people who can find alarms annoying or disruptive.
  • Smartphone compatibility. Sensor readings can either be viewed on the FreeStyle Libre Reader or a compatible smartphone or smart device.
  • Integrated blood glucose and ketone meter. The FreeStyle Libre Reader also works as a finger prick blood glucose and ketone meter (using the Freestyle blood glucose monitoring strips or ketone monitoring strips). This makes it easier to monitor glucose and ketone levels when needed, without having to carry a second device through the FreeStyle Libre app.
  • No medication interference. The accuracy of the Freestyle Libre sensor isn’t affected by medications containing paracetamol.
  • Cost. Flash GM devices are more expensive than regular finger prick monitoring. However, Flash GM is more affordable than CGM devices for those not eligible for subsidised CGM or Flash GM products through the CGM Initiative as part of the NDSS.

Downsides to Flash GM

While Flash GM offers many benefits, there are also things that some people don’t like or find difficult, and these are important to consider before deciding to use Flash GM.

  • Doesn’t completely replace blood glucose monitoring. While using Flash GM can reduce the number of finger prick checks needed, finger prick checks are still recommended when glucose levels are changing rapidly, to confirm hypoglycaemia, when symptoms don’t match the sensor reading and when adjusting insulin doses.
  • Accuracy. Flash GM devices measures the level of glucose in the interstitial fluid (the fluid between your cells) rather than the blood. Because glucose travels to the blood first and then to the fluid between the cells, Flash GM readings and blood glucose levels will not usually be exactly the same. When glucose levels are stable the readings should be close, but there will be a greater difference when glucose levels are either rising or falling quickly.
  • Being attached. Some people don’t like wearing a sensor, particularly if they are also using an insulin pump, as they then have two different devices attached to their body. For young children, lean adults and older individuals, it can also be difficult to find suitable sites in which to insert the sensor because they don’t have much body fat.
  • Staying attached. It can be difficult for some people to keep the sensor attached, particularly if they spend a lot of time in water and/or sweat a lot during exercise. The sensor might also be knocked off while playing or during sport. Unfortunately, if the sensor falls out, they can’t be reused. This can usually be prevented by using extra tape to keep the sensor attached. Your diabetes health care team can provide advice on the available options and which tape might be best for you.
  • Skin reactions. Some people may experience allergic reactions, skin rashes, itching, bleeding or bruising in the area where the sensor is inserted.
  • Discomfort. There may also be some mild pain or discomfort during insertion. Your diabetes health care team can provide advice on reducing the risk of these problems and managing them if they do occur.
  • Information overload. It can also be overwhelming to see what glucose levels are doing all the time. Your diabetes health care team can help you to learn how to use and interpret this information so that it can be used to improve diabetes management rather than becoming something else to worry about, particularly if glucose levels are out of target.
  • No alarms. Unlike CGM, Flash GM doesn’t have automated alerts when glucose levels move outside your target range. This means that the device will not alert you of hypoglycaemia or hyperglycaemia unless you scan at the times your glucose levels are low or high.
  • No insulin pump integration. Flash GM devices do not integrate with any insulin pumps and can only be used as a standalone device.
  • Cost. Flash GM is more expensive than finger prick blood glucose monitoring. If you are not eligible for subsidised Flash GM products through the NDSS, the cost of the FreeStyle Libre is $2,500 per year and is unlikely to be covered by private health insurance. This is a lower cost than CGM but higher than regular finger prick blood glucose monitoring.
Flash GM sensors measure glucose levels in the interstitial fluid and not the blood.

Government-subsidised Flash GM

The Australian Government provides access to fully subsidised Flash GM products for eligible people through the CGM Initiative as part of the NDSS. Eligible people are the following groups:

  • Type 1 diabetes; Age Under 21 Years
    Children and young people with type 1 diabetes aged under 21 years
  • Type 1 diabetes; Age 21 Years and Older with Valid Concessional Status
    People with type 1 diabetes aged 21 years and older who have valid concessional status
  • Type 1 diabetes; Pregnancy/Post-Pregnancy
    Women with type 1 diabetes who are actively planning pregnancy, pregnant or immediately post-pregnancy
  • Conditions similar to type 1 diabetes; Age Under 21 Years
    Children and young people aged under 21 years with conditions very similar to type 1 diabetes who require insulin

For more information about the eligibility criteria for each of these groups, visit

Choosing Flash GM

Whether you choose Flash GM instead of CGM will depend on a number of factors including:

  • if you want a device with alarm settings to inform you when your glucose levels move outside your individually set target range
  • whether you prefer a device that doesn’t need calibrating
  • if the device will be used in conjunction with an insulin pump, a compatible smartphone or separate receiver/reader
  • whether you want the option of sharing glucose data; and
  • personal preference.

Choosing the right device for you should be done with your diabetes health care team. They can provide you with all the information you need about Flash GM and about the different types of CGM devices, and answer any questions you might have. Your diabetes health care team will advise you how to best use your device to manage your diabetes.

An up-to-date list of fully subsidised products available through the CGM Initiative as part of the NDSS can be found on the NDSS website at

Choosing the right device for you should be done with your diabetes health care team.

Accessing fully subsidised Flash GM

To access fully subsidised Flash GM through the NDSS you will need to be registered with the NDSS and meet the CGM Initiative eligibility criteria. If eligible, your authorising health professional will need to fill out and sign the Continuous and Flash Glucose Monitoring Access form appropriate to your eligibility group. These forms are available on the NDSS website at and include a list of the health professionals who are authorised to certify eligibility in each group.

When the form has been submitted and processed, the NDSS will contact you to confirm your eligibility. Once your eligibility is confirmed, you will receive an email or a letter from us explaining how to start accessing your fully subsided Flash GM sensor through the NDSS.

More information

If you are interested in learning more about Flash GM or CGM:

  • speak with your diabetes health care team
  • visit the NDSS website
  • call the NDSS Helpline on 1800 637 700. The Helpline operates between 8:30am and 5pm Monday to Friday and between 9am and 12 noon on Saturdays and national public holidays.

More information about Freestyle Libre can be found by visiting the supplier website

The NDSS and you

A wide range of services and support is available through the NDSS to help you manage your diabetes. This includes information on diabetes management through the NDSS Helpline and website. The products, services and education programs available can help you stay on top of your diabetes.

This fact sheet is intended as a guide only. It should not replace individual medical advice. If you have any concerns about your health, or further questions, you should contact your health professional.

Version 1 August 2020.