Can Gamma Entrainment Help You Sleep Better?
- iniyanjose
- 12 hours ago
- 3 min read
Have you ever noticed how your body naturally syncs to a beat—tapping a foot to music, matching your pace to a walking partner, or getting drowsy during a steady train ride?
That “syncing” tendency has a scientific name: entrainment. And researchers are now exploring whether the brain can be gently guided by rhythm too—especially at a frequency that keeps showing up in neuroscience: 40 hertz (40-Hz).
Why 40-Hz matters
Forty hertz sits in the range of faster brain rhythms sometimes called “gamma.” Gamma activity has been linked to how different brain networks coordinate timing—like an orchestra keeping a shared tempo. Researchers have been investigating whether steady 40-Hz sensory stimulation (like light or sound patterns) can encourage the brain to align with that rhythm.
What does this have to do with sleep?
Sleep isn’t just “switching off.” It’s a deeply timed process—your brain’s rhythms shift across the night, and your body’s internal clock helps align sleep with day/night cycles.
Here’s what early evidence suggests:
1) Insomnia symptoms (human study, objective sleep testing): A study reported that 30 minutes of 40-Hz light flicker in the evening was associated with improvements on polysomnography (the gold-standard sleep test) in children with insomnia symptoms—things like shorter time to fall asleep and better sleep efficiency. Important: this doesn’t prove it works the same way for adults, and it’s not yet the kind of broad, replicated evidence we’d want for a clinical recommendation.
2) Sleep disruption in Alzheimer’s (human studies, actigraphy): Sleep fragmentation and day–night rhythm changes are common in Alzheimer’s. Reviews of clinical research report that 40-Hz sensory stimulation studies in Alzheimer’s populations have included sleep-related improvements (often measured with actigraphy/sleep scales), alongside safety and feasibility findings. Important: these studies are still relatively small, and actigraphy isn’t the same as full sleep-lab testing.
3) Can you deliver 40-Hz stimulation during sleep? A study in the journal SLEEP found that 40-Hz visual stimulation during sleep could evoke gamma activity without degrading sleep quality, supporting feasibility for future research.
What about circadian rhythms (your body clock)?
In animal research, 40-Hz light flicker has been reported to improve disrupted day–night activity patterns and to influence clock-related biology in the brain’s master clock region (the SCN). That’s intriguing—but animal results don’t automatically translate to humans.
ReviveXR and Sleep
ReviveXR has created a secret sauce that includes 40-hertz and other science backed strategies for enhanced relaxation and sleep. In a small scale feasibility study offered to participants with Alzheimer’s Disease over 3.5 months, we received positive anecdotal reports of enhanced quality of sleep, being able to go back to sleep after waking up in the night from every single participant of the study. This is of course, very preliminary data. But we are hoping to expand on this in the future.
The takeaway: 40-Hz stimulation is a promising research area at the intersection of brain rhythms, sleep, and circadian timing—but the science is still developing. If you’re someone who cares about brain health, aging, recovery, or sleep, this is a space worth watching.
(Safety note: rhythmic flickering light is not appropriate for everyone—especially people with photosensitive seizure risk. Always consult a qualified clinician for health decisions.)
If you’re curious, I’ll share more in upcoming posts: what entrainment is, what studies can—and can’t—claim, and how we think about designing rhythm-based experiences responsibly.