Sleep Cycle

Disease Category:
Target Audience:

Clinical Effectiveness
Version: 5.2.1
Developer: NorthCube AB
Review Date: 2016-04-27
Cost: Free + Premium versions

Overall App Summary:

Sleep Cycle is in a crowded field of sleep apps claiming to awaken the user after a sleep at just the right time to offer a more enjoyable awakening – more relaxed, comfortable and natural. Sleep Cycle uses the smartphone microphone and/or accelerometer to determine sleep patterns and sleep quality, in order to make judgement re: the timing of awakening. Apps in these categories, including Sleep Cycle, use methods that have not been validated and are likely invalid. In addition to the lack of methodology support, Sleep Cycle itself, provides no studies or data to show its own effectiveness. Are its users waking up more comfortably? Does it measure “light” and “deep” sleep per its claims?


App’s Intended Use:

Sleep Cycle purports to analyze sleep cycles, allowing its alarm clock function to awaken the user in the “lightest sleep phase” as to promote a more “feeling rested and relaxed” upon awakening. The methods this app uses to analyze sleep, which are used by many other related sleep apps, has not been validated and is likely invalid. Thus, it is likely to provide false sleep reporting to its users and mechanism for awakening that has not been proven to work.


Who’s this app most useful for?

This app is intended for people who want a more comfortable and “natural” awakening after sleep. It is not recommended because its makers have not demonstrated it to be effective. Further, the methods it uses to track sleep have not been validated and are likely inaccurate.


How should one use it?

The user may be interested in the visual reports generated as they are pleasing to the eye and may offer some sort of insight into sounds or movements generated during sleep, although their utility is unknown.


Why should anyone use this app? Is it clinically relevant?

Sleep Cycle uses sound (from the sleeping user) and can detect the sleeper’s motion (when their smart phone is alongside their body during sleep), neither of which have been shown to correlate with sleep cycles strongly enough to be useful in the ways Sleep Cycle claims. Thus, the methods used by Sleep Cycle have not been validated and Sleep Cycle, the app itself, has not been validated.


Is there any published evidence that the app actually works?

Not that the reviewers are aware of. However, the app does have at times outdated or incorrect information.



Regulatory Compliance

Most likely not going to be regulated by the FDA under the mobile medical application guidance.


What is the most important/ desirable feature of the app?

The interface is pleasing, easy to use, and straight forward. However, this may deceive the user, who may believe that it is a clinically useful app.


How is the app’s design and usability?

Outstanding (Professional design); able to start using the app immediately without significant training/ help.



How would you compare this app to other’s in its category?

Sleep Cycle’s functionality is very similar to other sleep apps that claim to awaken the user “at the right time.” None have been shown to be effective.


If there’s a paid version, is it worth the upgrade?

The premium, paid version, was not reviewed.


Security and Privacy

Password: Not required
Data Security: No mention
Data Sharing: No mention
Regulatory Compliance:

Adam Cohen

Dr. Adam B. Cohen, a Michigan native, is a neurologist & neuro-ophthalmologist at Massachusetts General Hospital in Boston, Massachusetts, where he is the Neurology Inpatient Medical Director and TeleNeurology Co-Director. He focuses on process innovation, digital health, and improving the efficiency of specialty health care delivery.

Conflicts of Interest:

Employment: Massachusetts General Hospital and Harvard Medical School; Consultant/ Advisor: Decibel Therapeutics, EM Gladiators LLC; Ownership: Expertaj; Research: Academic only; no private funding.

Maulik Majmudar

Dr. Maulik Majmudar is a practicing cardiologist and Associate Director of the Healthcare Transformation Lab at Massachusetts General Hospital; and an Instructor at Harvard Medical School. He lectures at Massachusetts Institute of Technology in areas of healthcare innovation & entrepreneurship, as well as medical device design and development. Dr. Majmudar started his career as a medical student at Northwestern University Feinberg School of Medicine, completed resident training in Internal Medicine at The Johns Hopkins Hospital, and followed by a fellowship in Cardiovascular Medicine at Brigham and Women's Hospital at Harvard Medical School. You can follow him @mmajmudar

Conflicts of Interest:

Employment: Massachusetts General Hospital and Harvard Medical School; Consultant/ Advisor: AliveCor, BioFourmis, Cardiogram, EchoSense, Facebook, HUINNO, MC10, Nokia; Ownership: BioFourmis, Cardiogram, HiLabs, Quanttus; Research: EchoSense, GE Healthcare, MIT.

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