Being tired behind the wheel can be as dangerous as driving while drunk¹. Yet, whereas showing up to work intoxicated can lead to dismissal, being visibly sleepy doesn’t tend to have comparable consequences — at least for now.

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As employers learn more about the productivity and safety costs of inadequate rest, might lack of sleep be treated as a sackable offence? And, if sleep can be enhanced to give workers wakeful benefits that go beyond those of a conventional night’s rest, might employers expect people to take such measures? These questions are not far-fetched.

Early attempts by companies to manage the risks from their employees’ poor sleep have already tested legal and ethical boundaries. In 2016, the Dutch Data Protection Authority investigated two companies that had provided employees with devices to track their activity, including sleep patterns in one case (see go.nature.com/4wwnzzx; in Dutch). The agency ruled the collection of such data impermissible, noting that they constituted sensitive health information and that employee consent could not be regarded as having been given freely, owing to the inherent power imbalance.

Digital systems that permit fine-grained monitoring of sleep are becoming increasingly widespread and accepted, as governments, health systems and insurers pay closer attention to sleep as an important public-health lever. Meanwhile, research and product development are shifting from merely measuring sleep and treating sleep disorders to enhancing sleep technologically, potentially altering expectations for what counts as healthy rest.

Once sleep becomes something that institutions can quantify, governments can frame as a public-health necessity and technologies can supposedly optimize, the stakes are raised beyond individual lifestyle choices and ethical questions come to the fore.

When does institutional support for better sleep turn into an expectation? Who will receive access to sleep enhancement and who will bear the costs of sleep deprivation? Who will be least able to refuse the offer of a better night’s sleep, despite it potentially being a means to subtle surveillance? Researchers, ethicists and policymakers must explore such concerns before the technology matures and is used more widely.

Why sleep loss matters

Sleep supports basic aspects of human life, including cognition, physical health, productivity, emotional regulation and even relationships, moral judgement and behaviour^2–4. Yet, despite scientific consensus on the importance of rest, chronic sleep deprivation remains widespread.

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Sleep problems have been described as an emerging global epidemic⁵. In some high-income countries, at least one-third of adults sleep less than the recommended minimum of seven hours a night⁶, a deficiency associated with an increased risk of cardiovascular disease, metabolic disorders, poor mental health, impaired cognitive performance and accidents³. Severe sleep disturbances have also been documented in many low-income countries⁵. All told, hundreds of billions of US dollars are lost each year through reduced economic output owing to insufficient sleep⁶.

Insomnia and related sleep disorders can be treated through cognitive behavioural therapy or medication. However, sleep deprivation can also result from policy choices, workplace design and social norms that shape when, how and for whom rest is possible^3,6.

In cases in which sleep loss is driven by work schedules, economic insecurity or social rewards for being constantly available, treating individuals mainly with drugs can risk obscuring the conditions that undermine rest in the first place. Emerging technologies complicate this landscape further.

Monitoring and enhancement

Wearable devices are used widely to track sleep and physiological signals, including heart rate and blood oxygen levels. These data are typically presented as summaries and trends, with artificial-intelligence-enabled tools used increasingly to identify patterns and generate personalized feedback⁷.

Users can adjust everyday behaviours (such as bedtimes or late-night caffeine consumption) and observe how these changes affect their sleep⁷. Wearable-supported interventions might reduce sleep disturbance, although their effects on total sleep time have not been established clearly and the quality of evidence for most outcomes is low⁸.

Other technologies aim to shape sleep. Non-invasive brain-stimulation devices induce electrical currents in the brain — using electrodes placed on the scalp or magnetic fields — to modulate its activity during sleep. Other sensory approaches deliver sounds, gentle motion or odours to influence brain rhythms, including those characterizing deep sleep⁹.

Such biohacking approaches seek to improve the restorative process itself, including the timing, continuity, efficiency and healing effects of sleep. The aim is to improve both health and performance while awake.

Yet, evidence of practical benefit is still limited. Most experiments have been laboratory-based and the effects vary between different methods and study designs. Bioethical work on enriching sleep remains nascent. Previous analyses focused mostly on wakefulness enhancement: measures intended to control when people sleep, reduce the amount required or maintain performance despite sleep deprivation, including interventions that carry health risks^10,11.

If evidence of benefit from enhancing sleep grows, these technologies could become normalized and embedded in people’s homes. Using them to boost sleep might not feel like cheating or accepting a health risk to gain an advantage. But there are strings attached.

Ethical concerns

Sleep enhancement sounds relatively benign, much like seeking better nutrition or working out. Concerns about unnaturalness or threats to authenticity and the value of achievement that are prominent in debates about enhancement in other areas, such as sports or cognitive performance¹¹, are muted in the case of sleep.

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Moreover, sleep-enhancement tools that rely on continuous, passive data collection operate during an unconscious state. Because the sleeping person isn’t affected directly by the monitoring while it happens, it might seem like a small imposition.

Yet, these same characteristics might make it easier for institutions to pressure people into using these technologies supposedly as a means of care. For example, consider two employment policies: one requires workers to use a cognitive enhancer, such as modafinil, to maintain alertness¹¹; the other requires people to participate in a wearable-based sleep-optimization programme. The latter might seem easier to justify, even though it involves intrusive monitoring.

It’s easy for companies to cite research backing such a programme. For example, a four-week field experiment found that employees who wore a headband delivering precisely timed sounds while they slept reported better work engagement and task performance the next day¹². (Whether these benefits extended to employees’ lives beyond the workplace was not assessed.)

Employers in safety-critical industries such as medicine, aviation and construction might view sleep enhancement or monitoring as a way to prevent harm resulting from fatigue. For example, a 2018 report on two UK pilot projects in railway construction recommended equipping the entire workforce with tracking devices¹³. In the trials, these devices enabled supervisors to look at predicted alertness scores before shifts and anonymized analyses were shared with management.

Normalizing the routine collection of sleep data could make it easier for companies to engage in other forms of bodily surveillance, encompassing stress, fitness or other health-related domains¹⁴. None of these concerns is an argument against sleep enhancement itself. But researchers and policymakers should look at the broader issues beyond sleep metrics and work-related targets to ask how an intervention affects the sleeper’s overall well-being¹⁵ and whether it respects their rights. The need for scrutiny is especially great in safety-critical contexts, in which technologically enhanced rest might come to be treated as a professional responsibility owed to others¹¹.

Responsible-governance priorities