Category: FreeStyle Libre Systems Tips
Get the glucose alerts* you need, when you need them, with the Libre app†.
Alarms* are designed to help you catch glucose changes sooner—so you can act quickly and stay in range. You can set optional alarms in the Libre app† to let you know when your glucose numbers go above or below your chosen range, right on your smartphone† or smartwatch‡§. Plus, with FreeStyle Libre systems, you can rely on accurate1 glucose readings every minute, all day long||.
Here are 5 commonly asked questions about alarms*.
1. How can I turn on and manage glucose alarms in the Libre app?
To turn on, check, or change your glucose alarms*, tap Alarms on the navigation bar in the Libre app†. When glucose alarms are turned on, the app lets you know the minute your glucose goes above or below your set levels.
You can set high and low glucose ranges, turn alarms on or off, and choose your sound or vibration settings to fit your needs.
2. What alarms are available with the Libre app and which alarms can I customize?
The Libre app† has four types of alarms*1—two that are customizable (alarms you can set yourself) and two that are default (alarms you cannot change).
Customizable alarms*
Not actual patient data.
Low Glucose
The default Low Glucose Alarm is 70 mg/dL, but this is a customizable alarm—meaning you can change this number.
You’ll be notified the minute your glucose falls below the level you set.
You can also set a custom alarm tone.
High Glucose
The default High Glucose Alarm is set to 250 mg/dL, but this is a customizable alarm—meaning you can change this number.
You’ll be notified the minute your glucose rises above the level you set.
You can also set a custom alarm tone.
Note: Escalating alarms are made to be discreet. They start with a notification on your smartphone’s home screen and a vibration that gets louder over time.
Not actual patient data.
Default alarms*
Urgent Low Glucose¶
Your Urgent Low Glucose Alarm is automatically set at 55 mg/dL.
Note: This alarm can’t be turned off, but can be silenced# for up to 6 hours using Silent Mode.
Not actual patient data.
Signal Loss
Signal Loss Alarm lets you know when glucose alarms aren’t available.
A notification will pop up on your smartphone’s home screen. It means your sensor hasn’t communicated with the app for 20 minutes. This may be because it is too far away or there is an issue with your sensor.
Discover how to set, customize, and understand your glucose alarms* in the Libre app†.
3. What range should I set my glucose alarms to?
You may decide to set optional, custom glucose alarms* so you know when to take action.
- Low Glucose Alarms can be set between 60 mg/dL and 100 mg/dL.
- High Glucose Alarms can be set between 120 mg/dL and 400 mg/dL.
Talk with your healthcare provider about the values you should choose to best work for your body.
4. Can alarms be silenced?
Yes. The Libre app† has a Silent Mode# setting under the Alarms menu.
It lets you set glucose and signal loss alarms* without sound# (and with vibration, based on your phone’s settings) for up to 6 hours at a time. You’ll see a notification on your smartphone’s home screen.
5. What happens if I don’t dismiss a glucose alarm notification when using the Libre app?
If you don’t dismiss a glucose alarm*, you’ll get a reminder from the Libre app† every 5 minutes while your glucose stays above or below your set limits.
Once you dismiss the alarm, it won’t appear again until your next high or low glucose reading.
Trust Libre systems for your important diabetes decisions.
With Libre systems, you’re covered—day and night||—as your custom alarms* alert you the moment your glucose is too low or too high.
Access our Libre systems guides for more information on alarms* and glucose readings, tips for wearing your sensor, and more.
Read Libre 3 Plus Sensor Guide | Read Libre 2 Plus Sensor Guide
Looking for extra support? Get free 1:1 sensor training with a Certified Diabetes Educator.
Connect one on one with a Certified Diabetes Educator over the phone—for free. They’ll walk you through sensor setup, show you how to read your glucose patterns, and answer any questions you have along the way.
Or call directly at 1-833-855-4273.
Available Monday–Friday, 8 AM to 8 PM Eastern Time (excluding major holidays)
100% free. No strings attached.
More articles you may enjoy
Use Libre app† reports to spot glucose patterns.
Get more from your glucose data with the reports feature.
How to get more from your glucose numbers
See how daily choices affect your glucose and how Libre systems show your unique patterns.
Build diabetes-friendly meals2 with a few steps.
Your guide to creating balanced meals—no complicated rules or counting
Share this article:
FreeStyle Libre 3 system is cleared to be used by children 4 years and older with Libre 3 sensor and 2 years and older with Libre 3 Plus sensor.
FreeStyle Libre 2 system is cleared to be used by children 4 years and older with Libre 2 sensor and 2 years and older with Libre 2 Plus sensor.
Medicare and other payor criteria may apply.
* Alarm notifications will only be received when alarms settings are enabled and turned on and sensor is within 20 feet (FreeStyle Libre 2) or 33 feet (FreeStyle Libre 3) unobstructed of the reading device.
† The FreeStyle Libre systems apps are only compatible with certain mobile devices and operating systems. Please check the Support section of our website for more information about device compatibility before using the apps. Use of the FreeStyle Libre systems apps may require registration with LibreView.
‡ The Libre app for smartwatches is only compatible with certain devices and operating systems. Please check the Support section of our website for more information about device compatibility before using the app. Use of the Libre app may require registration with LibreView. The Libre app for smartwatches should not be used to make treatment decisions. Please follow the Libre app instructions on your smartphone.
§ Glucose information and notifications will only be received when your smartphone is within range of your sensor and smartwatch. Notifications seen on your smartwatch are mirrored from the Libre app on your smartphone. You must enable the appropriate settings on your smartphone to receive alerts on your smartwatch.
|| 60-minute warm-up required when starting the sensor.
¶ To get the Urgent Low Glucose Alarm on your phone with the FreeStyle Libre systems apps, you will first need to start your FreeStyle Libre systems sensor with your phone. If you do not start your FreeStyle Libre systems sensor with your phone, you will not get the Urgent Low Glucose Alarm on your phone.
# Silent mode allows users to silence their signal loss and glucose alarms, including urgent low glucose alarm for up to six hours. You will not hear your glucose and signal loss alarms even if you've turned on Override Do Not Disturb but may still get the visual and vibratory notifications based on your phone's settings.
** Study was performed with the outside US version of the FreeStyle Libre 14 day system. Data is applicable to FreeStyle Libre 2 and 3 systems, as feature sets are similar as FreeStyle Libre 14 day system, excluding alarms.
♢ Eligible patients will receive one (1) FreeStyle Libre 2 Plus sensor or (1) FreeStyle Libre 3 Plus sensor for users with a compatible mobile phone operating system at $0 copay. The expiration date of the voucher is 60 days from the issue date. This program is available for patients with Type 1 diabetes or Type 2 diabetes or gestational diabetes. Patients ages 18 and older are eligible to sign up and receive an offer for the (1) FreeStyle Libre 2 Plus sensor or (1) FreeStyle Libre 3 Plus sensor. Patients ages 2–17 are eligible to receive an offer for the (1) FreeStyle Libre 2 Plus sensor or (1) FreeStyle Libre 3 Plus sensor through their parent or guardian. This offer is void where prohibited by law. Abbott may modify or rescind this offer at any time without notice. The discounts are not available to beneficiaries of Kaiser Permanente, Medicare, Medicaid or other federal or state healthcare programs, residents of Massachusetts, or US territories (other than Puerto Rico). The free (1) FreeStyle Libre 2 Plus sensor or (1) FreeStyle Libre 3 Plus sensor is provided as a sample and is limited to one sample per eligible person per product identification number. The FreeStyle Libre 2 Plus sensor or FreeStyle Libre 3 Plus sensor cannot be re-sold, traded nor submitted to any third-party payer for reimbursement and is not provided as any inducement for future purchases. The free sample card is not health insurance.
References: 1. FreeStyle Libre 2 and 3 User's Manuals. 2. ADA Nutrition & Wellness Team. “What Is the Diabetes Plate?” Diabetes Food Hub. American Diabetes Association, January 15, 2025. https://diabetesfoodhub.org/blog/what-diabetes-plate.
ADC-119352 v1.0