Only a few years ago, molecular hydrogen was mainly associated with its ability to neutralise certain harmful free radicals. Today, research is focusing on something perhaps even more significant: its ability to influence cellular signalling mechanisms, including the important protective Nrf2 pathway.
This could fundamentally change our understanding of how molecular hydrogen acts in the body.

1. What are free radicals and why does our body produce them?
Every cell in our body constantly generates energy, converts nutrients and carries out thousands of chemical reactions.
These processes also naturally produce reactive oxygen species (ROS). Some of them are free radicals – particles with an unpaired electron, which can be highly chemically reactive.
However, free radicals are not only harmful.
In appropriate amounts, they take part in important biological processes, such as cell communication, immune defence and the regulation of some adaptive mechanisms.
The problem arises when their production exceeds the body’s ability to maintain oxidation-reduction balance.
This state is called oxidative stress.
Long-term or excessive oxidative stress may contribute to damage to cell membranes, proteins and DNA. It is also linked to a number of processes associated with inflammation and ageing.
The goal, therefore, is not to eliminate all free radicals, but to keep their production and effects in balance.

2. How do antioxidants work?
The body has its own extensive antioxidant system.
It includes, for example, the enzymes superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx), as well as glutathione and other protective molecules.
This defence also includes substances obtained from food, such as vitamin C, vitamin E and various plant compounds.
Antioxidants work in several ways. Some can react directly with radicals, others support their enzymatic removal, regenerate other antioxidants or influence the formation of reactive substances.
Importantly, it is not simply a matter of supplying free electrons to the body. Antioxidant protection is a complex set of chemical reactions and biological regulatory processes.
And this is exactly where molecular hydrogen becomes exceptionally interesting.

3. Molecular hydrogen – a small molecule with unusual properties
Molecular hydrogen, H₂, is the smallest diatomic molecule.
Thanks to its small size and physical properties, it can diffuse relatively easily through biological membranes and reach various parts of the body.
Unlike many common antioxidants, H₂ is not a large or complex organic molecule. It is a simple gas made up of two hydrogen atoms.
The first major discovery: 2007
Molecular hydrogen first attracted major attention through the work of Japanese scientist Ikuroh Ohsawa and his colleagues, published in the prestigious journal Nature Medicine in 2007.
The researchers showed that, under experimental conditions, molecular hydrogen can react with highly reactive hydroxyl radicals (•OH) without reacting in the same way with all reactive oxygen species.
At the same time, they observed protective effects in cell experiments and in an animal model of ischaemia-reperfusion brain injury.
This gave rise to the idea of H₂ as a selectively acting antioxidant.
Today, however, we know that this explanation probably does not describe the full scope of its biological action.
Direct reactions of H₂ with radicals are limited by their rate and by competition from other molecules in the biological environment.
That is why researchers are looking for other mechanisms that could explain the observed effects of hydrogen even at relatively low concentrations.

4. Nrf2 – one of the main regulators of cellular protection
One of the most interesting directions of current research is the effect of molecular hydrogen on the Nrf2 signalling pathway.
Nrf2 (Nuclear factor erythroid 2-related factor 2) is a so-called transcription factor.
This means it takes part in controlling the activity of certain genes.
We can think of it as a regulator that helps the cell switch on its own protective mechanisms when needed.
Under normal circumstances, the amount of active Nrf2 in a cell is tightly regulated, among other things by the protein Keap1.
When a cell detects certain forms of oxidative or chemical stress, the regulatory mechanisms may change. Nrf2 is stabilised, enters the cell nucleus and influences the activity of genes whose products help the cell cope with the stress.
What can Nrf2 activation do?
Nrf2 controls an extensive network of protective processes. For example, it supports the production or renewal of certain enzymes and molecules involved in:
Maintaining antioxidant balance.
Glutathione metabolism and regeneration.
Protection against reactive chemicals.
Processing certain products of oxidative damage.
Maintaining cellular homeostasis.
Well-known target genes of this pathway include HMOX1, which encodes the enzyme HO-1, and NQO1, whose product helps protect cells against certain redox-active substances.
So Nrf2 does not act like a conventional antioxidant that directly neutralises a single radical molecule.
It helps regulate the system through which the cell protects itself.

5. How can molecular hydrogen influence Nrf2?
Experimental research shows that administering molecular hydrogen can, under certain conditions, influence Nrf2–Keap1 signalling.
In a number of cell and animal models, increased Nrf2 activity or changes in the expression of downstream protective proteins, such as HO-1, were observed after exposure to H₂.
This is important because it suggests that the effect of molecular hydrogen may not lie solely in direct reactions with radicals.
H₂ may indirectly influence the cells’ own antioxidant response.
Direct and indirect effects – a key difference
Direct antioxidant action: A molecule of the substance reacts chemically with a particular reactive particle.
Indirect action via Nrf2: The substance influences cell signalling and thus the activity of protective genes and enzymes.
The second mechanism is not a simple supply of electrons. It is a change in the way the cell responds to oxidative stress.
This possibility is among the most interesting hypotheses in current research on molecular hydrogen.
It is important to add, however, that it has not yet been clearly established which initial molecular interaction of H₂ triggers these signalling changes.
Nor has it been shown that every administration of hydrogen automatically activates Nrf2 in all tissues or under all circumstances.

6. Nrf2 is not the only signalling pathway under investigation
The biological action of H₂ is also being studied in relation to other regulatory systems.
One of them is NF-κB, which is involved in regulating inflammatory and immune responses.
Another is NLRP3, part of a cellular complex known as the inflammasome, which takes part in some inflammatory processes.
Experimental studies show that molecular hydrogen can, under certain conditions, influence signalling in these systems.
Research also focuses on mitochondria, energy metabolism and the interplay between oxidative stress and inflammation.
The current picture of molecular hydrogen is therefore broader than the mere neutralisation of free radicals.
Above all, its possible role in regulating the cellular stress response is being studied.

7. Why is it not desirable to keep Nrf2 permanently activated at maximum?
It might seem that the stronger the Nrf2 activation, the better.
But it is not that simple.
Nrf2 activity must be properly regulated. Its protective action can benefit healthy cells, whereas long-term excessive activity of this pathway can, in certain biological situations, also have undesirable consequences.
For example, some cancer cells can use increased Nrf2 activity to protect themselves against oxidative stress or treatment.
The goal, therefore, is not maximum Nrf2 activation, but properly functioning cellular regulation.
The effect of molecular hydrogen on this regulation is a promising subject of research, not proof that H₂ can safely and selectively activate protective mechanisms only where it is desirable.

8. What do human studies show so far?
Molecular hydrogen has been studied in various areas – for example in connection with physical exertion, recovery, metabolic markers and selected inflammatory or neurological conditions.
Some clinical studies have reported favourable changes in certain measured markers.
However, the results must be interpreted with caution.
Studies often involve small numbers of participants and use different H₂ concentrations, different methods of administration and different follow-up periods.
We also do not yet have enough high-quality clinical evidence to establish a universal effective dose of hydrogen or to reliably confirm its benefit for the prevention or treatment of specific diseases.
The results of cell and animal experiments cannot be automatically transferred to humans.
We therefore regard molecular hydrogen as a scientifically interesting substance with potential biological effects, whose clinical significance is still being researched.

9. Why did we start infusing drinks with hydrogen?
The development of TIRTAN was also prompted by observations of the oxidation-reduction properties of fresh fruit and vegetable juices.
In our measurements we found that some freshly prepared juices show a negative oxidation-reduction potential (ORP), which can change relatively quickly after juicing.
These changes led us to ask whether the electrochemical properties of drinks could be influenced by adding molecular hydrogen, without having to carry out electrolysis directly in them.
The result of several years of development is TIRTAN, which uses patented vortex technology.
The device produces hydrogen outside the drink being infused and then mechanically works it into the liquid using intense vortex flow.
This approach makes it possible to enrich not only water but also other suitable drinks with molecular hydrogen, without the hydrogen production itself altering their chemical composition through electrolysis.
Why don’t we focus only on ORP?
A negative ORP is a useful indicative measure of a change in the electrochemical properties of a drink.
On its own, however, it does not determine the concentration of molecular hydrogen or its biological effect.
That is why we distinguish between the ORP value, the actual H₂ concentration and the results of biological studies.
Today’s research shows us that the potential significance of molecular hydrogen does not lie only in how negative an ORP we can measure.
A far more interesting question is how H₂ can influence the regulatory processes of living cells themselves.

10. The future of hydrogen research: Nrf2 and cellular balance
From a scientific point of view, molecular hydrogen first began to attract significant attention because of its possible antioxidant action.
Today, the story is expanding to include research into cell signalling, mitochondrial function, inflammatory mechanisms and the regulation of gene expression.
Nrf2 – one of the important regulators of natural cellular protection – deserves special attention.
Perhaps the most interesting property of molecular hydrogen is not only its ability to react directly with certain free radicals, but its potential to influence the mechanisms by which the body itself maintains oxidation-reduction balance.
It is this hypothesis that is opening up new directions of research.

TIRTAN is a technology for preparing drinks enriched with molecular hydrogen. Its aim is to enable the practical use of this gas in drinks while knowledge of its biological effects continues to develop.
Disclaimer: This article is for information and educational purposes. The biological mechanisms described are the subject of scientific research, in which we collaborate with Palacký University Olomouc and the Slovak Academy of Sciences in Bratislava.
TIRTAN is not intended to diagnose, treat or prevent any disease, and its use does not replace medical care.