The Science Behind NSDR: What Research Actually Shows

NSDR promises better focus and recovery without sleep—but most articles just repeat Huberman clips. After reviewing 6 studies and 20+ hours of transcripts, here's what the research actually supports.

NSDR (Non-Sleep Deep Rest) is a guided relaxation practice that puts your brain into a state between waking and sleeping. You lie down, follow breathing and body-scan instructions, and stay conscious while your brain shifts into slower wave patterns.

The term was coined by Stanford neuroscientist Andrew Huberman as a secular alternative to yoga nidra, which has been practiced for thousands of years. As Huberman explains: "NSDR is a lot like yoga nidra but removes a lot of the mystical language and the intentions. It focuses more on the physiology and the body scans."

Here's what happens during a session:

• Your brain waves slow down. You shift from alert beta waves to relaxed alpha and theta waves.
• Your nervous system switches gears. The parasympathetic system activates, lowering heart rate and blood pressure.
• Stress hormones drop. Cortisol levels decrease measurably after a single session.

The most-cited finding: a 2002 study showed a 65% increase in dopamine during yoga nidra practice. That stat shows up everywhere. But there's important context most articles skip, which we'll cover below.

The Three Brain Changes During NSDR

1. Brain wave shift (beta → alpha → theta)

When you're fully awake and focused, your brain produces beta waves. During NSDR, activity slows to alpha waves (relaxed alertness) and then theta waves (the edge of sleep). This theta state is where the restorative effects happen.

2. Dopamine reset in the striatum

According to Huberman, research shows that "this meditation and yoga nidra type meditation allows dopamine and other neuromodulators in an area of the brain called the striatum that's involved in motor planning and motor execution to reset itself." This may explain why people feel refreshed and focused after a session. For a deeper dive into these neurological changes, see our guide on how NSDR changes your brain.

3. Cortisol reduction

Multiple studies show decreased cortisol after yoga nidra practice. Huberman cites research where "salivary cortisol reduced statistically significantly after yoga nidra." This is the most consistently replicated finding in the literature.

Let's be direct: the evidence for NSDR is promising but limited. Most studies are small, and the strongest research is on yoga nidra specifically, not the rebranded NSDR protocols.

Here's what the science shows:

My take: Strong evidence for relaxation and stress reduction. Weaker evidence for the cognitive claims that get repeated on social media.

The Dopamine Study Everyone Cites (And What They Get Wrong)

The 65% dopamine increase stat comes from a 2002 study by Kjaer and colleagues at the University of Copenhagen. It's real science, published in Cognitive Brain Research. But context matters.

What the study actually did:

Eight experienced yoga teachers (not beginners) underwent PET scans while practicing yoga nidra. Researchers measured dopamine binding in the striatum. The 7.9% decrease in raclopride binding corresponds to approximately 65% increase in endogenous dopamine release.

What gets lost in translation:

• These were highly experienced practitioners, not people doing their first 10-minute YouTube session
• The sessions were about an hour long
• The study had only 8 participants

Does this mean NSDR doesn't boost dopamine for beginners? Not necessarily. But extrapolating a 65% increase to every YouTube video is a stretch.

What the 2024 Research Adds

The more recent studies are methodologically stronger, even if the sample sizes remain small.

Boukhris et al. (2024) tested 65 physically active participants with a 10-minute NSDR protocol. The results:

• Enhanced handgrip strength
• Improved cognitive performance on attention and executive function tasks
• Better perceptions of physical readiness and emotional balance
• Reduced muscular stress and negative emotional states

This is the first study to test a short NSDR protocol (not traditional hour-long yoga nidra) on physical and cognitive outcomes. The findings support using NSDR as a quick reset, not just a relaxation tool.

The cardiac rehabilitation study (2024) found that NSDR reduced depression, anxiety, and perceived stress in patients with coronary artery disease. It's preliminary evidence, but suggests applications beyond just healthy people looking for a productivity boost.

Most explanations throw around terms like "parasympathetic activation" without explaining what that actually means. Here's the mechanism in plain language.

The Sleep-Wake Spectrum (You're Not Fully Awake or Asleep)

We tend to think of consciousness as binary: you're either awake or asleep. But that's not how the brain works.

There's a spectrum between full alertness and deep sleep. NSDR targets the middle zone, sometimes called the "hypnagogic state" or "liminal state." You're conscious enough to follow instructions but relaxed enough for restorative processes to occur.

This explains why NSDR can work when naps sometimes backfire. With naps, you might slip into deeper sleep stages and wake up groggy (sleep inertia). With NSDR, you stay in the lighter restorative zone without fully going under.

Why Brain Waves Matter (Alpha, Theta, Delta Explained)

Your brain produces different electrical patterns depending on your state:

NSDR moves you from beta into alpha and theta without dropping into delta (actual sleep). The theta state is associated with increased creativity, memory consolidation, and reduced stress hormones.

The Parasympathetic Switch

Your autonomic nervous system has two modes:

Sympathetic: Fight-or-flight. Heart rate up, stress hormones released, ready for action.

Parasympathetic: Rest-and-digest. Heart rate down, relaxation, recovery.

Modern life keeps many people stuck in sympathetic mode. NSDR deliberately activates the parasympathetic system through:

• Slow, controlled breathing
• Progressive body relaxation
• Reduced sensory input (eyes closed, still position)

The cortisol reduction seen in studies is a measurable sign that this switch is happening. This is the most reliably replicated finding across NSDR and yoga nidra research.

Let's address the elephant in the room: NSDR and yoga nidra are functionally the same practice.

Huberman is transparent about this. He's stated that he created the term NSDR because yoga nidra sounded too "mystical" for some audiences. It was a rebranding for accessibility, not a scientific innovation.

The honest answer: If you're doing a body scan while lying down and following breathing cues, you're doing yoga nidra regardless of what the video title says. The research applies to both.

Why Huberman Rebranded It

Huberman has explained his reasoning: "I want to acknowledge that yoga nidra has been around for thousands of years and was certainly there before NSDR."

The rebranding worked. Google searches for "NSDR" have grown significantly since 2022, bringing relaxation practices to people who might have scrolled past "yoga nidra."

Is it marketing? Yes. Does that make it less effective? No. Call it whatever helps you actually do it.

These three practices overlap but serve different purposes. Here's a decision framework:

When NSDR Beats Napping

For afternoon recovery, NSDR is usually better than a nap. Here's why:

• Flexibility: You can do 10, 20, or 30 minutes based on available time
• No grogginess: Staying in lighter states avoids sleep inertia
• Easier to do: No need to fall asleep (which some people struggle with)
• Multiple sessions: You can do NSDR twice daily without disrupting nighttime sleep

The Boukhris 2024 study showed measurable benefits from just 10 minutes, which is faster than most people can fall asleep for a nap.

When Meditation Beats NSDR

If you want to improve attention and focus, traditional meditation has stronger evidence.

NSDR is passive. You follow instructions without much effort. Meditation (especially focused-attention types) requires actively directing and redirecting attention. That active training appears to strengthen attention networks more than passive relaxation.

Choose meditation if your goal is: concentration improvement, emotional regulation training, or building a daily mindfulness practice.

Choose NSDR if your goal is: quick recovery, stress reduction, or falling asleep. If sleep is your main concern, you might also find our guide on how to fall asleep faster using Huberman's protocol helpful.

When Nothing Replaces Sleep

NSDR is a supplement, never a replacement for sleep.

Sleep researcher Matthew Walker and others have been clear: memory consolidation and certain restorative processes only happen during actual sleep stages. No amount of NSDR can substitute for the deep sleep your brain needs.

The 2024 Harvard thesis found inconclusive results when testing whether NSDR could counter the cognitive effects of sleep deprivation. Translation: it might help you feel better, but it won't undo the damage of skipped sleep.

No practice works for everyone in all situations. Here's where the NSDR hype exceeds the evidence.

It Won't Replace Lost Sleep

The productivity influencers who suggest NSDR can substitute for sleep are overselling it. The Harvard 2024 thesis specifically tested this and found non-significant effects on attention and working memory in sleep-deprived students.

NSDR might help you push through an afternoon after a bad night. It won't erase sleep debt.

The Research Sample Size Problem

Most NSDR and yoga nidra studies have small samples:

• Kjaer 2002 dopamine study: 8 participants
• Most yoga nidra studies: 20-50 participants
• Boukhris 2024: 65 participants (largest I found)

This doesn't mean the findings are wrong. It means we should hold them loosely. "Promising direction" is more accurate than "proven science."

Individual Response Varies

Some people find NSDR deeply restorative. Others report feeling restless or bored. If it doesn't work for you after 5-10 sessions, it may not be your practice.

This isn't a how-to guide, but here are the research-backed parameters.

Duration: 10 vs. 20 vs. 30 Minutes

Start with 10 minutes. The Boukhris study showed benefits from a 10-minute protocol. Longer isn't necessarily better.

Huberman recommends 10-30 minutes depending on available time. Traditional yoga nidra sessions run 30-60 minutes, but modern protocols have shortened this.

If you're pressed for time: 10 minutes works. If you have more time: 20-30 minutes may deepen the effects.

Best Time to Practice

Afternoon (2-5pm) is ideal for most people. This targets the natural "postprandial dip" (post-lunch energy drop) that occurs in circadian rhythm. For specific timing recommendations based on your goals, see our guide on the best times to practice NSDR.

Avoid using NSDR as a sleep replacement when you're significantly sleep-deprived. The research doesn't support that application.

Where to Find Protocols

Huberman has released free NSDR protocols on YouTube. Search "NSDR Huberman" for his 10 and 20-minute versions. Traditional yoga nidra recordings from experienced teachers work identically.

Does NSDR increase dopamine?

Yes, but context matters. The 2002 Kjaer study showed 65% dopamine increase in experienced practitioners during an hour-long session. Whether a 10-minute YouTube video produces the same effect in beginners is unknown. The mechanism is real; the magnitude may vary.

Is NSDR just yoga nidra?

Functionally, yes. Huberman coined NSDR as a secular, science-forward term for the same practice. Think of NSDR as yoga nidra's secular cousin. The research applies to both.

Can NSDR replace sleep?

No. Memory consolidation and certain restorative processes only occur during actual sleep stages. NSDR is a recovery tool, not a sleep substitute. The Harvard 2024 thesis found inconclusive results for countering sleep deprivation with NSDR.

How long does it take to see benefits?

Acute benefits (reduced stress, improved alertness) can occur after a single session. Cumulative benefits for sleep quality appear after 2+ weeks of regular practice, based on the 2022 insomnia study.

Who shouldn't do NSDR?

People with certain psychiatric conditions should consult a healthcare provider first. Pregnant women should avoid supine positions after the first trimester. Otherwise, NSDR is generally safe for most people.

Studies:

• Kjaer TW, et al. (2002). Increased dopamine tone during meditation-induced change of consciousness. Cognitive Brain Research. PubMed: 11958969
• Boukhris O, et al. (2024). The acute effects of nonsleep deep rest on perceptual responses, physical, and cognitive performance. Applied Psychology: Health and Well-Being. PubMed: 38953770
• Harvard DASH (2024). Testing Non-Sleep Deep Rest (NSDR) protocol to counter the cognitive consequences of short sleep in young adult students.
• MDPI (2024). Non-Sleep Deep Rest Relaxation and Virtual Reality Therapy for Psychological Outcomes in Patients with Coronary Artery Disease. J Clin Med. 13(23):7178

YouTube Sources:

• Huberman Lab Podcast #96: How Meditation Works & Science-Based Effective Meditations (wTBSGgbIvsY)
• Huberman Lab Essentials: Master Your Sleep & Be More Alert When Awake (lIo9FcrljDk)