Most wellness trends collapse when you ask a simple question: what actually is it? Hydrogen water survives that question — which is more than can be said for a lot of what fills health store shelves. The concept is simple, the science is real, and the research behind it is substantial. Here's what the chemistry actually says.
The Simple Answer
Water with extra hydrogen dissolved in it
Hydrogen water is regular water that's been enhanced with dissolved molecular hydrogen gas (H2). Nothing in the water's fundamental chemistry changes. The mineral content stays the same. The pH stays the same. You're dissolving the same gas that makes up most of the universe — in a very small quantity — into ordinary water.
The result goes by several names: hydrogen-rich water, hydrogenated water, or HRW. These terms are interchangeable. What they describe is water hydrogen-rich with dissolved H2 gas, measured in parts per million. No restructured molecules. No energetic charge. Just dissolved gas.
Molecular hydrogen versus hydrogen ions — two entirely different things
Hydrogen ions (H+) are charged particles that determine acidity and alkalinity. Molecular hydrogen — the kind found in hydrogen water as studied in clinical research — is a neutral gas molecule: two hydrogen atoms bonded together (H2). No charge. Entirely different chemistry and behavior.
Alkaline hydrogen water products sometimes conflate these two things. Drinking hydrogen-rich water, as studied in published research, means consuming water with dissolved H2 gas — not water that's simply been made alkaline.
How Hydrogen Dissolves in Water — and Why It Doesn't Stay Forever
Water can dissolve gases, but only up to a point. Henry's Law sets a natural ceiling: at room temperature and standard atmospheric pressure, water can hold approximately 1.6 parts per million of dissolved molecular hydrogen gas — roughly 1.6 milligrams per liter.
Hydrogen doesn't stay in water indefinitely. Open a glass to the air and H2 begins escaping through off-gassing. Temperature accelerates this. So does agitation. How hydrogen-rich water is generated, stored, and consumed matters significantly for how much H2 actually reaches the person drinking it.
Understanding PPM — the unit of hydrogen concentration
Parts per million (PPM) is the standard unit for hydrogen concentration in water. One ppm equals one milligram of dissolved H2 per liter. Research studies examining the health effects of drinking hydrogen water have generally used concentrations from 0.5 ppm to approximately 1.6 ppm, which represents the effective saturation limit under standard conditions. Some devices use pressurization to push concentrations higher, though the clinical significance of concentrations above 1.6 ppm hasn't been well characterized. Our dedicated piece on what PPM, PPB, and ORP actually measure unpacks the units and why ORP is not a hydrogen reading.
How Hydrogen Water Differs from Regular Water
Chemically, the difference is exactly one thing: the presence of dissolved H2 gas. Nothing else changes. No altered crystal lattice, no special molecular structure. The water tastes essentially the same — some people report a slightly different mouthfeel at high-concentration hydrogen levels, but this varies and is anecdotal.
What stays the same
Mineral content stays the same. pH stays the same. The only variable is the amount of dissolved molecular hydrogen gas. This means any biological effects researchers observe in hydrogen-rich water trials are attributable to the H2 itself — not to mineral changes or alkalinity. That's an important feature of how the research has been designed.
Hydrogen Water vs. Alkaline Water
Alkaline water has a pH above 7 — typically between 8 and 10. This elevated pH comes from dissolved minerals or from electrolysis processes that generate hydroxide ions. Hydrogen water and alkaline water are separate categories. High-concentration hydrogen water can have a pH that is essentially neutral. We covered this distinction in detail in our piece on hydrogen water vs. alkaline water, which walks through why the two are routinely confused.
pH and hydrogen concentration measure completely different things
Alkalinity measures hydroxide ion (OH-) concentration. Hydrogen concentration measures dissolved H2 gas. A standard pH meter tells you nothing about H2 content; a dissolved hydrogen meter or ORP meter is required. Most published clinical trials on hydrogen-rich water used pH-neutral water specifically, so outcomes observed in those studies are not attributable to alkalinity as a confounding variable. The Lourdes Hydrofix Premium Edition produces water at approximately pH neutral (±0.1 from source water) — meaning its characteristics are driven by dissolved H2, not altered pH.
You can find the Lourdes Hydrofix in our hydrogen water machine collection.
How Hydrogen Water Is Made
Three main approaches exist, each producing meaningfully different results in concentration, consistency, and purity.
Tablets and portable generators
Hydrogen tablets dropped into water create a chemical reaction that releases H2 gas, some of which dissolves before escaping. Portable bottle generators use small electrolytic cells powered by a rechargeable battery. Water that has been injected with hydrogen gas under elevated pressure is used in some canned and bottled products — though these face off-gassing challenges once opened. All three approaches can produce measurable dissolved hydrogen, but concentration and consistency vary significantly.
Countertop electrolysis systems
Countertop electrolysis machines pass an electrical current through water via a specialized membrane, separating water into hydrogen and oxygen, then dissolving the hydrogen back into the drinking water stream. These systems can operate continuously at higher flow rates and maintain more consistent dissolved H2 concentrations than portable approaches.
Why the generation method affects what you actually get
Not all electrolysis designs are equal. Single-chamber systems generate hydrogen and oxygen in the same space, which can allow cross-contamination. Dual-chamber (separate-chamber) designs keep these streams physically isolated, affecting both purity and achievable concentration. Our dedicated piece on separate-chamber vs. single-chamber electrolysis walks through why this design choice drives most of the variation between machines. Solid polymer electrolyte (SPE/PEM) membranes enable cleaner hydrogen generation than basic alkaline electrolysis approaches. The Lourdes Hydrofix Premium Edition uses a separate-chamber design with a multi-layer fibriform polymer membrane. Under test conditions, it produced approximately 134.2 mL/min of hydrogen gas, measured by Masa International Corp. (Test No. MM03-6024-01; full documentation available at holyhydrogen.com/pages/certifications), achieving up to approximately 1.6 ppm under normal operating conditions.
What the Research Shows
The body of published science on molecular hydrogen is substantial — and accelerating. More than 80 human clinical trials have now been conducted, alongside hundreds of pre-clinical studies examining mechanisms, biomarkers, and applications across a wide range of health areas. Serious scientists at peer-reviewed journals worldwide are publishing on this topic because the findings are interesting enough to warrant continued investigation.
The 2007 study that put molecular hydrogen on the map
The published research has a clear starting point. In a landmark 2007 paper in Nature Medicine, Ohsawa et al. proposed that molecular hydrogen may act as a selective antioxidant — a hypothesis that subsequent research continues to explore. Their work suggested that H2 might interact preferentially with hydroxyl radicals and peroxynitrite (two of the most cytotoxic reactive oxygen species) while leaving other ROS that serve beneficial physiological roles largely undisturbed. That selectivity hypothesis distinguished this work from earlier, broader antioxidant research and launched a wave of follow-on investigation in clinical trials and human studies (Ohsawa I, Ishikawa M, Takahashi K, et al. Nature Medicine. 2007;13:688–694. PMID: 17486089).
What clinical trials have examined since
Human studies have since examined hydrogen-rich water across exercise capacity, oxidative stress biomarkers, liver function, cardiovascular disease indicators, cognitive effects, and metabolic health. A 2024 systematic review by Dhillon et al., published in the International Journal of Molecular Sciences, analyzed 25 controlled studies and found consistently positive trends across these areas — noting, as systematic reviews in emerging research fields typically do, that larger standardized trials would further strengthen the evidence base. That call for more research reflects the normal arc of a field gaining momentum, not a reason for skepticism: over 2,000 published peer-reviewed papers now exist on molecular hydrogen, including more than 80 human clinical trials, and the pace of publication continues to accelerate (Dhillon G, Buddhavarapu V, Grewal H, et al. Int J Mol Sci. 2024;25(2):973. PMID: 38256045).
The information above reflects topics explored in published scientific research on molecular hydrogen. It does not describe the function of the Lourdes Hydrofix device. The Lourdes Hydrofix is a hydrogen water generator — not a medical device — and is not intended to diagnose, treat, cure, or prevent any disease.
Safety and FDA Status
The U.S. Food and Drug Administration has granted molecular hydrogen "Generally Recognized As Safe" (GRAS) status for use in food and beverages, documented under GRN No. 520. No known adverse effects from consuming hydrogen-rich water have been reported in the peer-reviewed literature — unsurprising, given that the substance is water with dissolved H2 gas that simply dissipates if not absorbed.
What "GRAS" actually means
GRAS designation means that qualified scientific experts have reviewed available evidence and concluded the substance is safe for human consumption under intended conditions. It is not a therapeutic claim. It doesn't establish that hydrogen water treats or prevents any disease. It establishes that it is safe to drink — which is the baseline question when evaluating any novel beverage ingredient. For a product with the research trajectory that molecular hydrogen carries, that safety foundation matters.
How Most People Use Hydrogen Water
Many hydrogen water users incorporate it into a morning routine — two large glasses before eating, typically around 400–500 mL at a time. Some users drink approximately 2 liters per day. This reflects common practice among long-term users and the reference intake used in many research studies. It is not a medical protocol; optimal intake for any individual is not established by the evidence. Timing matters in a practical sense: water hydrogen-rich with dissolved gas is most concentrated immediately after generation. Off-gassing begins once hydrogen water is exposed to air, which is why countertop system users typically drink at the point of production.
Where to Go Next
The foundational question — what is this thing — now has an answer. What comes next is the question that actually matters: what does the research say it can offer?
For a careful look at what clinical trials have actually found — positive results, study design, and how to read the evidence properly — see Does Hydrogen Water Actually Work? A Look at the Evidence.
For readers who have encountered skeptical coverage and want to evaluate those critiques with the published research in hand, Is Hydrogen Water a Scam? What the Evidence Actually Says addresses the most common objections directly.
Given the engineering criteria the published research implies — chamber design, membrane type, electrode material, and consistent concentration at the point of consumption — here is how those criteria are addressed in practice. The Lourdes Hydrofix Premium Edition product page includes the third-party test certificates and lab data that support its performance specifications.
Related Reading
- Does Hydrogen Water Actually Work? A Look at the Evidence
- Is Hydrogen Water a Scam? What the Evidence Actually Says
- Hydrogen Water vs. Alkaline Water: What's Actually Different
- Understanding PPM, PPB, and ORP: What the Numbers on Your Hydrogen Machine Actually Mean
- Separate-Chamber vs. Single-Chamber Electrolysis: Why the Design of Your Machine Matters
Holy Hydrogen products, including the Lourdes Hydrofix Premium Edition, are not medical devices and are not intended to diagnose, treat, cure, or prevent any disease. All information on this site is provided for educational and general wellness purposes only and should not be considered medical advice. Always consult a qualified healthcare provider before beginning any new wellness practice, especially if you have a medical condition, are pregnant or nursing, or take prescription medications.
Further Reading
For the broader peer-reviewed literature on molecular hydrogen and hydrogen-rich water, see PubMed's filtered results. The papers below are good entry points into the science:
- Ohsawa et al. (2007), Nature Medicine. PMID: 17486089. The landmark paper that introduced the selective antioxidant hypothesis — proposing that H2 preferentially reduces the most cytotoxic reactive oxygen species (hydroxyl radicals and peroxynitrite) while leaving useful signaling ROS alone. Every later trial in the field traces back to this paper.
- Dhillon et al. (2024), International Journal of Molecular Sciences. PMID: 38256045. A systematic review of 25 controlled hydrogen-water studies that found consistently positive trends across exercise capacity, oxidative stress, liver function, and metabolic markers — while calling for larger standardized trials, as is typical of an emerging research field.
- Johnsen et al. (2023), Molecules. PMID: 38067515. A clinical-trials review that catalogues 81 registered hydrogen trials and 64 published human studies across cardiovascular, respiratory, central nervous system, infection, and cancer-adjacent areas — useful for getting a bird's-eye view of where the human research has actually gone.
- LeBaron et al. (2022), International Journal of Molecular Sciences (Review I). PMID: 36499079. A review walking through the history of electrolyzed-reduced water and demonstrating, study by study, that the observed effects come from dissolved H2 itself — not from alkaline pH, negative ORP, "microclustering," or other claimed properties. Helpful for separating the chemistry from the marketing.
- LeBaron et al. (2022), International Journal of Molecular Sciences (Review II — Safety). PMID: 36498838. A safety-focused review of electrolyzed-reduced water, including the case for measuring actual H2 concentration rather than relying on ORP or pH proxies, and the recommendation that pH should not exceed 9.8.
- Zhou et al. (2024), Metabolites. PMID: 39452918. A review of hydrogen-rich water's effects on athletic performance — endurance, strength, sprint times, time to exhaustion — and a clear summary of the proposed redox-homeostasis mechanisms, while flagging that not every study has shown a benefit.
References
- Ohsawa I, Ishikawa M, Takahashi K, Watanabe M, Nishimaki K, Yamagata K, Katsura K, Katayama Y, Asoh S, Ohta S. Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. Nature Medicine. 2007;13:688–694. PMID: 17486089.
- Dhillon G, Buddhavarapu V, Grewal H, Sharma P, Verma RK, Munjal R, Devadoss R, Kashyap R. Hydrogen Water: Extra Healthy or a Hoax?—A Systematic Review. International Journal of Molecular Sciences. 2024;25(2):973. PMID: 38256045.
- U.S. Food and Drug Administration. GRAS Notices: Hydrogen Gas (GRN No. 520). Available at: hfpappexternal.fda.gov.