Sleep shows up in the hydrogen water research mostly as a side measurement. Teams studying appetite, aging, exercise and long COVID added sleep to their outcome lists, and in the two trials whose full text is open, sleep was scored with a questionnaire. The four small human trials covered here each report a sleep result, and they do not agree with each other.
Read closely, one shows a larger improvement with hydrogen on a measure that was not a primary outcome, one shows a difference on a single part of a questionnaire while the overall score did not differ, and two found no significant difference from control water. A mouse study adds objective sleep recordings, with its own caveats.
The Appetite Trial That Put Sleep in Its Title
HYDRAPPET was an 8-week randomized, double-blind trial in adults with obesity, with 35 participants in the analysis. One group drank 1.0 L a day of hydrogen-rich water, delivering 15 mg of hydrogen across three servings, and the other drank the same amount of tap water [1]. Sleep was measured with the Pittsburgh Sleep Quality Index (PSQI), a self-rated questionnaire with seven components where higher scores mean worse sleep.
The total PSQI score fell by an average of 2.2 points in both groups, from 6.9 to 4.8 with hydrogen and from 7.5 to 5.2 with tap water [1]. The difference between groups over time was not significant (p = 0.92). In the full sample, the one sleep result that separated the groups was a single component, subjective sleep quality, at p = 0.05. That component is the basis for the abstract’s statement that hydrogen improved subjective sleep quality.
The authors did not correct for multiple comparisons, citing the exploratory nature of the study and its small sample, and they note that self-reported questionnaires are open to bias [1]. One co-author is employed by Natural Wellness Now Health Products, the company that supplied the drinks. Appetite and cholesterol results from the same trial are a separate question from sleep.
The Long COVID Trial
A 2024 pilot trial randomized 32 adults with lingering fatigue and breathlessness after COVID to hydrogen-rich water from an electrolysis device or plain water in identical packaging, twice a day for 14 days [2]. Its primary outcomes were fatigue, breathlessness, walking distance and a chair-stand test. Sleep, measured with the PSQI, was not one of them.
The PSQI score in the hydrogen group went from 6.06 to 3.31, and in the plain water group from 4.63 to 4.00 [2]. The percent change was significantly greater with hydrogen (p = 0.012). The hydrogen group also started with worse sleep scores. In an exploratory analysis of participants who reported difficulty sleeping, the formal test of whether the groups changed differently over time was only marginal (p = 0.064).
The authors list a small sample, single blinding that might have introduced bias, and a 14-day intervention that may be too short [2]. They also describe the PSQI as measuring sleep over one month, which is longer than the time participants spent drinking the water. Of the four trials, this is the most favorable to hydrogen, and sleep was still not a primary outcome of the pilot study.
Two Trials Where Sleep Did Not Separate From Control
A six-month randomized pilot trial gave 40 adults aged 70 and over either 0.5 L a day of hydrogen-rich water or control water and assessed sleep among many other measures [3]. Hydrogen beat control on telomere length, a DNA methylation marker, some brain metabolite levels and a chair-stand test. Sleep was among the outcomes with no significant difference between groups.
A six-week double-blind trial in 27 adults over 50 who were starting resistance training gave hydrogen-rich water or control water twice a day [4]. Hydrogen reduced markers of exercise muscle damage more than control did. For sleep, the authors write that hydrogen tended to outperform control, with p = 0.119, which is not statistically significant.
Who Ran These Studies
Three of the four human trials, the appetite, aging and exercise studies, come from the Applied Bioenergetics Lab at the University of Novi Sad in Serbia, with the same senior author [1][3][4]. In two of them a co-author is listed with Natural Wellness Now Health Products, and HYDRAPPET states that company provided the interventions. The long COVID trial was run by a separate group in China [2].
None of that makes a result wrong. It does mean the human sleep data come mostly from one research group, and that the trial with the clearest sleep signal is a single 14-day pilot study.
What the Mouse Study Showed
The one study here built around sleep recorded it objectively, in mice. Animals fitted with brain and muscle electrodes drank hydrogen-rich water or regular water for seven days, and their sleep was recorded at baseline and after sleep deprivation [5]. Hydrogen increased sleep consolidation in undisturbed mice, increased both non-REM and REM sleep after sleep loss, and shortened the time to fall asleep after lights came on.
The study was funded by the US National Institutes of Health. Its disclosure statement says one author has accepted speaking and consulting fees regarding molecular hydrogen and another holds a patent on hydrogen-rich water tablets [5]. Mouse sleep is also not human sleep, so this is a reason to run a human trial with objective sleep measures, not a substitute for one.
A Plausible but Unproven Mechanism
In cell and rat experiments, hydrogen selectively reduced the hydroxyl radical, the most damaging reactive oxygen species, without reacting with other reactive oxygen species that have normal roles in the body [6]. That finding is the usual basis for calling hydrogen a selective antioxidant.
A 2018 review proposed a framework in which inflammation and oxidative stress may drive sleep problems in neuro-immune conditions such as chronic fatigue syndrome, bipolar disorder and multiple sclerosis [7]. It named molecular hydrogen, alongside melatonin, as a therapeutic target that holds promise in those disorders. No human trial has tested whether any sleep effect of hydrogen water actually runs through that pathway.
Practical Takeaway
The human evidence covered here is four small trials, with 27 to 40 participants each. One found a larger improvement with hydrogen on a non-primary measure [2], one found a difference on one questionnaire component while the total score did not differ [1], and two found no significant difference [3][4]. That is not enough to call hydrogen water a sleep aid.
In the appetite trial, people drinking plain tap water improved their total sleep score by the same amount as the hydrogen group [1]. That is a reminder that sleep questionnaire scores can improve during a trial for reasons that have nothing to do with the drink. If you drink hydrogen water and sleep better, the drink may not be the reason.
If better sleep is the goal, the habits with a far stronger evidence base come first: a consistent sleep schedule, managing light exposure in the evening, and getting persistent sleep problems checked for an underlying disorder.
References
- The Effects of 8-Week Hydrogen-Rich Water Consumption on Appetite, Body Composition, Sleep Quality, and Circulating Glucagon-like Peptide-1 in Obese Men and Women (HYDRAPPET): A Randomized Controlled Trial. Medicina, 2025
- The Effect of 14-Day Consumption of Hydrogen-Rich Water Alleviates Fatigue but Does Not Ameliorate Dyspnea in Long-COVID Patients: A Pilot, Single-Blind, and Randomized, Controlled Trial. Nutrients, 2024
- The effects of 6-month hydrogen-rich water intake on molecular and phenotypic biomarkers of aging in older adults aged 70 years and over: A randomized controlled pilot trial. Experimental Gerontology, 2021
- The effects of drinking hydrogen-rich water for six weeks on exercise-related biomarkers in exercise-naïve men and women over 50 years following resistance training program: a randomized controlled pilot trial. Research in Sports Medicine, 2025
- Hydrogen-rich water improves sleep consolidation and enhances forebrain neuronal activation in mice. Sleep Advances, 2024
- Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. Nature Medicine, 2007
- The putative role of oxidative stress and inflammation in the pathophysiology of sleep dysfunction across neuropsychiatric disorders: Focus on chronic fatigue syndrome, bipolar disorder and multiple sclerosis. Sleep Medicine Reviews, 2018
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease. Content is for informational purposes only and is not medical advice; consult a qualified healthcare provider before starting any supplement. As an Amazon Associate we earn from qualifying purchases.
