Getting enough deep sleep is not just good for rest—it’s also essential for building strong muscles, healthy bones, and burning fat.
Bodybuilders often rely on deep sleep for growth hormone release, and teens need it to reach their full height. But until now, scientists didn’t fully understand why missing sleep reduces growth hormone levels.
A new study from the University of California, Berkeley, finally offers answers. Researchers discovered the brain circuits that control the release of growth hormone during different sleep phases, and they uncovered a new feedback loop that keeps the hormone levels in balance.
Their findings, published in the journal Cell, help explain how sleep and hormone control are connected. These insights could lead to better treatments for sleep problems, metabolic disorders like diabetes, and even brain diseases such as Parkinson’s and Alzheimer’s.
The lead author of the study, Dr. Xinlu Ding, said that while earlier studies only looked at hormone levels in blood, this new research actually measured brain activity in real time using mice. “We’re showing what’s really going on inside the brain,” she said.
Growth hormone plays a major role in how the body handles sugar and fat, so not getting enough sleep could also increase the risk of gaining weight, developing diabetes, or having heart problems.
Deep in the brain, inside a part called the hypothalamus, are special neurons that control growth hormone release. These include growth hormone-releasing hormone (GHRH) neurons, which turn it on, and somatostatin neurons, which turn it off. The released hormone then activates another part of the brain called the locus coeruleus, which is involved in waking us up, focusing, and reacting to new things. When this part of the brain doesn’t work right, it can lead to mental health and brain disorders.
Dr. Daniel Silverman, a co-author of the study, said that learning how this brain system works could help scientists develop hormone-based treatments to improve sleep and brain function. “This circuit could give us a new way to calm the brain when it’s too active,” he explained.
To explore these brain circuits, the research team inserted tiny electrodes into mice brains and used light to trigger specific neurons. Mice sleep often in short bursts, making them perfect for studying how hormone levels change during sleep and wake cycles.
The scientists found that the two brain chemicals controlling growth hormone work differently during different types of sleep. During REM sleep, when dreams happen, both somatostatin and GHRH increase together to boost growth hormone. But during non-REM sleep—the deep, restful kind—GHRH goes up a little while somatostatin drops, which also increases growth hormone.
Here’s the surprise: the growth hormone that gets released during sleep later activates the brain’s arousal center, the locus coeruleus, helping the brain wake up. This creates a loop where sleep boosts growth hormone, and growth hormone, in turn, helps control how alert we feel. But too much of it may even lead to tiredness, showing how tightly balanced the system must be.
“Sleep drives growth hormone, and growth hormone controls wakefulness. That balance is key for health,” said Silverman. This balance may affect more than just physical growth—it might also improve brain function and thinking.
So, growth hormone not only builds muscle and burns fat, but it might also make you feel more alert and focused when you wake up. As Ding explained, “It may also have mental benefits by helping your brain work better after a good night’s sleep.”
If you care about sleep health, please read studies about foods that help people sleep better, and Keto diet could improve cognitive function in people with sleep loss.
For more health information, please see recent studies about the natural supplements for sound sleep, and how your diet can improve sleep quality.
Copyright © 2025 Knowridge Science Report. All rights reserved.
