- What is the NC° Band, and how does it work with Natural Cycles?
- How effective is Natural Cycles when used with the NC° Band?
- Who is the NC° Band available to, and where can I buy it?
- Should I wear the NC° Band during the day?
- Is the NC° Band waterproof?
- How to know the NC° Band battery status
- How to wear the NC° Band with the silicone strap
- Can I sync temperatures for multiple days at once?
- Why was my temperature not recorded?
What is the NC° Band, and how does it work with Natural Cycles?
The NC° Band is a smart, overnight wearable designed specifically to take the hassle out of manual morning temperature logging. You simply wear it to sleep, and it seamlessly syncs with your Natural Cycles app in the morning to update your daily fertility status.
While you sleep, the band continuously records three major biological indicators:
- Body Temperature: This is the core data point used by the NC° algorithm to calculate your fertility status.
- Heart Rate: This helps the algorithm detect variations in your typical routine (such as changes in sleep quality or if you are fighting off an illness).
- Motion: This tracks movement to ensure the device only saves temperature data collected while you are fully asleep.
*Please keep in mind that using the NC° Band is not the same as measuring orally with a thermometer, and should not be used for fever detection. Temperatures collected from the band should not be compared to measurements from an oral thermometer or other devices. We write more about this here: Why different measuring devices give different temperatures.
Quick Start Guide: How to Use the NC° Band Every Night
- Before going to bed: Wear the band on your inner wrist. We recommend using your non-dominant hand.
- When you wake up: In the morning, open your Natural Cycles app. To activate your band's Bluetooth, simply touch/move the band or place it briefly on its charger. Your data will upload automatically, and your daily fertility status will instantly refresh.
Here are a few more tips on syncing your NC° Band with Natural Cycles you may find helpful:
- For optimal use of the NC° app, we recommend you sync your NC° Band data every morning.
- Ensure that your latest temperature data syncs and is saved before you check your fertility status for the day, as today’s new data may update your daily fertility status.
How effective is Natural Cycles when used with the NC° Band?
The effectiveness of Natural Cycles remains the same whether you use an oral basal thermometer, the NC° Band, the Oura Ring, a compatible Garmin device, or the Apple Watch. Natural Cycles is 93% effective with typical use and 98% effective with perfect use. You can learn more about Natural Cycles’ effectiveness here: How effective is NC° Birth Control?
Who is the NC° Band available to, and where can I buy it?
At the moment, the NC° Band is only available for users in Europe, the UK, the US, Canada, Australia, and Brazil while supplies last.
We're working hard to expand availability to more users as soon as possible. Please stay tuned for updates!
If you are located in one of these countries, you can purchase the NC° Band either when you sign up for your Natural Cycles subscription or directly from the Buy Extra Supplies section (found in the app's top menu). It’s also available for purchase in our NC° Shop in the US, UK, and Europe.
Common questions
Should I wear the NC° Band during the day?
To use your NC° Band with the NC° app, you only need to wear it while you sleep, and there is no need to wear it during the day.
Is the NC° Band waterproof?
You should avoid fully submerging your NC° Band in water.
While the band has IP65 waterproof protection and can handle splashes, you should not shower, bathe, or swim while wearing it.
How to know the NC° Band battery status
You can check the battery status in the app by going to the top menu > My Device > Device details.
When charging your device, the light indicates the following:
- Pulsating light: the band is charging. A full charge takes ~2.5 hours.
- Steady light: the battery is fully charged.
The band’s battery has been optimized to last up to 14 days.
To record a full night of sleep, avoid having a critically low battery level before going to sleep.
Does the NC° Band emit EMF frequencies, and can I turn off Bluetooth?
The NC° Band is designed with user safety in mind and meets country-specific and global consumer electronic device requirements, including both CE marking and FCC certification.
Independent testing conducted by TÜV SÜD confirmed the band emits a maximum of 1.41 mW, which is significantly below the European health and safety limit of 20 mW.
To further minimize exposure and preserve battery life, the band’s Bluetooth automatically turns off after five minutes of stillness. When Bluetooth is active, it transmits only in very short bursts (approximately 6 milliseconds every 2 seconds), even during syncing. This results in significantly lower exposure than common devices like smartphones or Wi-Fi routers.
How to wear the NC° Band with the silicone strap
The NC° Band comes with a nylon strap by default. If you prefer, you can purchase a silicone strap in the app under Buy Extra Supplies.
Please note that the silicone strap is currently available in limited quantities. If you don’t see it in your app yet, thank you for your patience—we’re working hard to make it available to everyone soon.
Below you will find instructions on how to wear the NC° Band with the silicone strap:
To extract your temperature data, your NC° Band sensor needs consistent skin contact on your inner wrist. The silicone strap is designed to be adjustable—aim for a fit that is snug enough to stay in place while you sleep, but gentle enough to allow for the natural swelling that happens overnight. It’s completely normal if it takes a few nights to find your perfect band size for a comfortable fit.
Can I sync temperatures for multiple days at once?
If, for any reason, you skipped syncing your temperature data for a few days but wore your band at night, that data will automatically sync the next time you open the app.
When you open the app, a pop-up will appear, displaying your unsynced temperatures in a list with the date of each temperature. Click on "Save" in the pop-up to sync all the previously unsynced temperatures to the Natural Cycles app.
Here’s some important information to keep in mind:
- If you sync temperatures for the past days, the algorithm will consider all the new data, and you may see changes in your fertility status on the days when new temperature data was added.
- The band stores 2-3 weeks of temperatures if only worn at night.
For these reasons, we recommend that you try to sync your temperature every day instead of syncing multiple temperatures at once.
Why was my temperature not recorded?
The algorithm requires a continuous block of at least 4 hours of sleep to accurately extract your resting basal temperature. If you see an "Interrupted Sleep" or “Not enough data” error message, it is usually because:
- You slept for less than 4 hours total
- The band lost skin contact during the night because the strap was too loose
- The band was not positioned correctly on your wrist
- The band's battery died mid-sleep
If you run into any issues with your NC° Band, don’t hesitate to get in touch with our Customer Care team. We're here to help!