The science · 科学依据
It started with one paper in 2007.
Hydrogen had been breathed by divers since the 1940s and studied on and off for decades. Then a Japanese team showed it was doing something far more interesting than anyone expected — and the field opened.
Everything below is published work. We link the originals so you can check us.
The origin
Professor Shigeo Ohta, Nippon Medical School.
In 2007 Ohta’s group published in Nature Medicine that molecular hydrogen acts as a selective antioxidant: it neutralises the hydroxyl radical (·OH) and peroxynitrite (ONOO⁻) — the two species that actually drive DNA damage, lipid peroxidation and mitochondrial collapse — while leaving the milder reactive oxygen species your cells use for signalling intact.
That single distinction is why hydrogen behaves differently from every antioxidant that came before it, and why the research volume went from a trickle to a flood.
Source · Ohsawa I, Ishikawa M, Takahashi K, et al. (Ohta S, senior author). Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals. Nature Medicine 13, 688–694 (2007).
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H₂ used in the original inhalation experiments
Disease models studied since, per Ohta’s reviews
Daltons — the smallest molecule there is
Not all free radicals are enemies.
Your body makes reactive oxygen species on purpose — for signalling, for immune defence. Only two of them are unambiguously destructive. Those are the two hydrogen reacts with.
| Species | What it does in the body | H₂ reacts? |
| H₂O₂ Hydrogen peroxide |
Cell signalling, growth, differentiation | Left alone |
| O₂⁻ Superoxide |
Immune defence, signalling | Left alone |
| ROO· Peroxyl radical |
Moderately damaging | Largely left alone |
| RO· Alkoxyl radical |
Moderately damaging | Largely left alone |
| HOCl Hypochlorous acid |
Immune defence against pathogens | Left alone |
| ·OH Hydroxyl radical |
The most destructive species in biology | Neutralised |
| ONOO⁻ Peroxynitrite |
Potent oxidant, many pathologies | Reduced |
Why selectivity is the whole point
A conventional antioxidant — vitamin C, vitamin E — clears reactive species indiscriminately, which is one proposed explanation for why high-dose antioxidant supplementation has repeatedly disappointed in large trials: it may suppress useful signalling along with the damage. Hydrogen’s narrow reactivity is not a limitation. It is the reason it can be taken daily without blunting normal physiology.
Bioavailability
Two daltons. Nothing else gets in like this.
Vitamin C is hydrophilic and stops at the membrane. Vitamin E is lipophilic and needs a carrier. Coenzyme Q10 is far too large to cross into the brain. Hydrogen is electrically neutral, non-polar, and the smallest molecule in the universe — it diffuses where nothing else can follow.
01 · Through the blood-brain barrier
One of very few antioxidant molecules that reaches the central nervous system directly, rather than acting only in the periphery.
02 · Into the mitochondria
Oxidative stress originates at the cell’s energy plant. Hydrogen reaches the source rather than mopping up downstream.
03 · Into the nucleus
Where DNA sits. Protection at this level is why much of the research interest centres on ageing and long-term cellular health.
04 · Everywhere else, quickly
Inhaled hydrogen diffuses systemically within minutes. It is not targeted to one organ, and it does not accumulate.
What is left afterwards
H₂ + 2·OH → 2H₂O
When hydrogen neutralises hydroxyl radicals, the product is water. There is no metabolite to process, no residue to accumulate, no burden on the liver or kidneys. This is the plainest reason the safety profile is what it is.
From a diving gas to clinical consideration.
Six moments that moved hydrogen from curiosity to something health systems felt obliged to evaluate.
Diving
1943
Swedish engineer Arne Zetterström makes the first documented use of a hydrogen–oxygen breathing mix for deep diving, reaching 160 m. The first evidence humans tolerate hydrogen at sustained pressure.
Early research
1975
Dole, Wilson and Fife report regression of skin tumours in mice under hyperbaric hydrogen, published in Science. Suggestive, never followed up at scale, and worth knowing about precisely because it went quiet.
Foundation
2007
Ohta’s group publishes the selective-antioxidant mechanism in Nature Medicine. The modern field begins here.
Emergency medicine
2016
Japan’s Ministry of Health, Labour and Welfare lists hydrogen inhalation as Advanced Medical Care B for post-cardiac-arrest syndrome, following a first-in-human pilot study published in Circulation Journal.
National protocol
2020
China’s National Health Commission includes hydrogen–oxygen inhalation in the seventh edition COVID-19 treatment protocol. A multi-centre trial associated with Academician Zhong Nanshan reports improvement in dyspnoea and disease severity.
Accumulated evidence
Today
Research spans well over a hundred disease models, with clinical trials registered across Asia, Europe and North America. Most remain small. The direction is consistent; the certainty is not yet there.
Source · Zetterström hydrox dives 1943–45 · Dole, Wilson & Fife, Science 190:152–154 (1975) · Ohsawa et al., Nature Medicine (2007) · Tamura et al., Circulation Journal (2016) · China NHC COVID-19 protocol 7th ed. · Guan et al., multi-centre H₂/O₂ trial (2020)
The people doing the work.
Hydrogen research is a small field with identifiable authors. These are the names you will meet repeatedly if you read the literature yourself.
Prof. Shigeo Ohta
Japan · Nippon Medical School
Senior author of the 2007 Nature Medicine paper that established selective antioxidation — the acknowledged starting point of the modern field. Has since published extensively on mechanism and on the regulatory path for hydrogen therapy.
Prof. Sun Xuejun 孙学军
China · Naval Medical University
Among the first in China to study hydrogen biology systematically. Author of the founding Chinese-language texts on the subject, including Hydrogen Molecular Biology (2013) and Hydrogen Gas Medicine (2020), with work cited several thousand times.
Academician Zhong Nanshan 钟南山
China · Respiratory medicine
Led and publicly backed the multi-centre hydrogen–oxygen inhalation research during COVID-19, which preceded the therapy’s inclusion in China’s seventh-edition national treatment protocol.
Prof. He Qianjun 何前军
China · SJTU Center of Hydrogen Science
Works on nanomaterial-controlled hydrogen release, published in Nature Communications and elsewhere — extending hydrogen from inhalation towards targeted delivery.
Tyler W. LeBaron
United States · Molecular Hydrogen Institute
Founded one of the earliest non-profit hydrogen research bodies. Compiles the global literature, pushes for trial registration, and is among the more vocal critics of overstated marketing claims within the industry.
Dole, Wilson & Fife
United States · 1975
The Science paper that first suggested a therapeutic role for hydrogen. Included here because the field then ignored it for thirty years — a useful reminder of how slowly this kind of evidence actually moves.
These researchers are not affiliated with H₂Hub and have not endorsed us. We list them because their published work is the evidence base we rely on — and because you should be able to read it without going through us.
Delivery
How you take it changes what you get.
This is the single most common source of confusion — and of misleading marketing. A result from an inhalation study does not transfer to a bottle of hydrogen water, and vice versa. The dose, the duration and the tissue reached are all different.
| Method | Dose delivered | Where it is studied | Practicality |
| Inhalation | Highest and most sustained | Cardiac arrest, COVID-19, most clinical protocols | Needs a device |
| Hydrogen-rich water | Lower, and it degasses quickly | Metabolic and exercise studies | Easy, portable |
| Hydrogen saline (IV) | Controlled, clinical only | Animal and hospital research | Not consumer |
| Baths and topical | Localised, poorly characterised | Thin literature | Limited evidence |
Our studio and home sessions use inhalation at 333 ml/min because that is where the clinical literature is concentrated. Hydrogen water is a reasonable complement, not a substitute.
Where the evidence is thin.
An honest map matters more than a long citation list. If you only read one section on this page, read this one.
Much of the literature is preclinical
A large share of published hydrogen studies are animal or cell-culture work. Promising mechanisms in mice do not automatically translate to outcomes in people, and the history of antioxidant research is full of exactly that failure.
Human trials are usually small
Many human studies run with dozens rather than hundreds of participants, over weeks rather than years. They are suggestive, not conclusive. Large, long, independently funded trials remain rare.
Delivery methods are not interchangeable
Inhalation, hydrogen-rich water and saline infusion deliver very different doses to different tissues. A finding from one should never be quoted as evidence for another — and frequently is.
Effect sizes vary widely between people
Some participants in published studies show clear changes; others show none. Nobody can currently predict which group you are in. This is why your first session is free rather than bundled into a package.
The 1975 result was never replicated at scale
Dole’s tumour-regression finding in Science sat unexamined for three decades. We include it in the timeline for honesty, not as evidence of anything about cancer. It is not a claim we make.
Read it, then try it.
The literature is public and we will point you to it. The session is free and takes an hour.
H₂Hub is a wellness studio, not a medical provider. Nothing on this page is a diagnosis, a treatment, or a promise of a clinical outcome, and it is not a substitute for advice from your doctor. Where we cite research, we cite it as research — published findings, not claims about what will happen to you.
The question that usually comes next: is it safe?
Hydrogen is flammable in a specific concentration range. We set out where that range actually sits, what these machines produce, and the shut-off systems involved — with the numbers, not reassurance.
Read the safety page →