History of Hydrogen Medicine: From Early Experiments to Modern H₂ Research

Before Medicine: Hydrogen Had to Become Hydrogen

The story begins centuries before anyone understood H₂ as a biological molecule. Historical accounts credit the 16th-century physician and alchemist Paracelsus with observing a mysterious flammable gas when metals reacted with acids. He did not identify it as the element we now call hydrogen, but the observation became part of the early history.

In 1766, Henry Cavendish studied what was then called “inflammable air” and helped establish it as a distinct gas. Later, Antoine Lavoisier helped give the gas its modern name: hydrogène, from roots associated with water and forming—essentially, “water-former.”

The Part of Hydrogen’s Medical History We Originally Missed

When we produced the original H2Minutes history episode, we jumped from the naming of hydrogen in the 1700s to Nicholas Senn’s work in 1888. Newer historical reviews bring an earlier chapter into much better focus.

In fact, hydrogen was being discussed in medical contexts nearly a century before Senn.

1888: Nicholas Senn Uses Hydrogen in Gastrointestinal Investigation

Nicholas Senn’s work remains an important historical milestone, but it needs to be described accurately.

In 1888, Senn reported the use of hydrogen gas to insufflate the gastrointestinal tract. At a time when surgeons had limited ways to identify intestinal perforation and visceral injury, hydrogen provided a way to help determine whether the gastrointestinal tract had been penetrated.

So this was a genuine medical use of hydrogen gas, but it was primarily diagnostic and surgical, not evidence that hydrogen itself was being used as a modern therapeutic treatment.

1940s–1960s: Hydrogen Moves Into Deep-Diving Physiology

The next important chapter came from deep diving. Swedish engineer Arne Zetterström experimented with hydrogen-containing breathing mixtures during the 1940s as researchers looked for alternatives that could support deeper diving under extreme pressure.

Later diving programs continued investigating hydrogen-containing respiratory mixtures. This work became important to the molecular-hydrogen field because it provided unusual physiological data on human and animal exposure to very high concentrations of H₂ under controlled hyperbaric conditions.

Modern reviews cite exposures as high as approximately 98.87% H₂ with about 1.13% O₂ at 19.1 atmospheres without observed toxic effects from the hydrogen itself. That does not mean every hydrogen inhalation setup is automatically safe—device engineering, gas mixtures, flammability, oxygen availability, ventilation, and the delivery interface still matter—but it is meaningful evidence that molecular hydrogen itself has a remarkably low biological toxicity profile.

For a modern discussion of hydrogen inhalation dose, delivery systems, engineering, and safety, see our Hydrogen Inhalation Therapy: The Ultimate Guide.

1975: Hydrogen Returns as an Experimental Therapy

One of the most important early modern biomedical studies appeared in Science in 1975.

Dole, Wilson, and Fife exposed mice with squamous-cell carcinoma to a hyperbaric gas mixture containing 97.5% hydrogen and 2.5% oxygen at eight atmospheres. The investigators reported a marked response in the tumors and proposed that hydrogen might be interacting with free-radical chemistry.

The experiment was unusual and highly preclinical, and later researchers were not able to reproduce the same outcome in every tumor model. But historically, the study mattered because it brought H₂ back into biomedical research and explicitly connected hydrogen with free-radical biology decades before the modern H₂ field took off.

2007: The Paper That Changed the Modern H₂ Field

Then came the paper that most people in today’s molecular-hydrogen field recognize as the beginning of the modern era.

In 2007, Ikuroh Ohsawa and colleagues published “Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals” in Nature Medicine. In a rat model of cerebral ischemia-reperfusion injury, inhaled H₂ reduced oxidative injury and brain damage.

The original interpretation emphasized molecular hydrogen’s ability to selectively reduce highly reactive oxidants such as the hydroxyl radical while leaving other biologically important reactive species relatively undisturbed.

That explanation was important, but it turned out not to be the entire story. Research since then has expanded into redox regulation, gene expression, inflammatory signaling, mitochondrial function, cell-death pathways, immune regulation, metabolism, and other mechanisms.

From a Few Papers to a Global Research Field

The numbers in our original H2Minutes script are now badly outdated—and that is actually good news.

The old episode referred to roughly 600 studies and reviews. Today, H2HUBB’s public Molecular Hydrogen Research Library alone contains more than 1,600 published research records, including human evidence, reviews, laboratory research, animal studies, and multiple H₂ delivery methods.

Researchers have now investigated molecular hydrogen through inhalation, hydrogen-rich water, hydrogen-rich saline, baths, topical applications, ophthalmic delivery, and other methods. The research spans oxidative stress, inflammation, cardiovascular health, neurological conditions, exercise, metabolism, respiratory health, immune regulation, and many other areas.

2014 and Beyond: Research, Regulation, and Real-World H₂ Products

As the science expanded, molecular hydrogen also started moving into consumer products and more formal research infrastructure.

In the United States, FDA GRAS Notice 520 received a “no questions” response for hydrogen gas as a food ingredient in certain beverages. That is an important food-use milestone, but it should not be confused with FDA approval of molecular hydrogen as a medical treatment.

At the same time, clinical research continued to expand, especially in Japan, China, Korea, Europe, and other regions. Hydrogen inhalation, hydrogen-rich water, and other delivery methods have now been investigated in a growing number of human populations.

This is also where H2HUBB’s work fits into the modern history. The field now has not only researchers studying H₂ biology, but also a real consumer marketplace filled with hydrogen water bottles, inhalation devices, tablets, machines, testing technology, and other products. That makes independent product testing, performance standards, research education, and accurate hydrogen-dose information increasingly important.

Final Thoughts: Hydrogen’s Medical History Is Older Than Most People Realize

The most interesting thing about hydrogen’s history is that the idea keeps resurfacing.

Physicians were experimenting with hydrogen-containing gases in the 1790s. Surgeons were using hydrogen diagnostically in the 1800s. Divers and physiologists studied hydrogen-containing breathing mixtures in the 1900s. Dole and colleagues investigated hyperbaric H₂ in 1975. Then the 2007 Nature Medicine paper gave the field a modern mechanistic foundation and helped turn scattered historical interest into sustained research.

From our perspective at H2HUBB, that history matters because it changes how you look at the field. Molecular hydrogen is not simply a new wellness trend that appeared with hydrogen water bottles. It is a molecule with a long and unusual scientific history that is still being worked out today.

And that may be the most accurate ending to this story: we are still in the history of molecular hydrogen right now.