20/11/2025
ます）
“Does Hydrogen Gas Inhalation Really Work?”
— A Medical Perspective Triggered by the Shohei Ohtani Coverage
“Hollywood actresses and top athletes are using it.”
Health trends with such taglines have appeared throughout history. While chatting with a patient today, an article in Josei Seven about Shohei Ohtani’s “hydrogen bed” became a hot topic.
The article mentioned that many celebrities—including stage actress Yuki Amami—have incorporated “hydrogen inhalation” into their daily lives.
But what matters most here is a single question:
“What does the science actually say?”
Years ago, I wrote a book on hydrogen therapy—nearly a decade ago now.
(Research has advanced since then, and I would like to update my views.)
As physicians, we must speak based on data, not promotional claims.
■ Bottom line:
Does inhaled hydrogen gas enter the body in amounts large enough to affect the whole system?
→ Based on current science, the answer is closer to NO.
Let me explain carefully.
1. Hydrogen behaves completely differently from oxygen
After oxygen enters the lungs, it binds to hemoglobin—the body's “transport vehicle”—and is carried throughout the bloodstream.
However:
Hydrogen has no equivalent transport molecule.
In other words, there is no “truck” that carries hydrogen through the body. Even if hydrogen reaches the lungs, it is unlikely to circulate throughout the body in the way oxygen does.
Additionally:
Lung breathing works by negative pressure.
Air flows into the alveoli due to physical negative pressure.
But the “ease of dissolution into blood” (diffusion capacity) varies among substances.
Hydrogen, being very small, may diffuse slightly from the alveoli into the blood.
However, its solubility in blood is extremely low (Henry’s law), making it unlikely that enough hydrogen can be absorbed to reach the entire body.
2. Is it true that hydrogen removes only “bad” reactive oxygen species?
This originates from a Japanese basic science study in 2007:
Ohsawa et al., Nature Medicine, 2007; 13: 688–694.
Hydrogen gas was shown in vitro to selectively reduce:
• Hydroxyl radicals (·OH)
• Peroxynitrite (ONOO–)
But a crucial note:
This is based on test-tube and animal studies.
Large-scale clinical trials in humans have not demonstrated decisive benefits.
Furthermore, the body’s antioxidant system is already finely regulated:
• SOD
• Catalase
• Glutathione
…all work in harmony.
Health does not simply improve by adding large amounts of external antioxidants.
(In fact, excess antioxidants can reduce performance — Cell Metabolism, 2014; 20: 356–368.)
3. Does hydrogen inhalation really aid recovery?
Hydrogen water, hydrogen IVs, hydrogen inhalation…
Research is underway globally, but:
No consistent clinical effectiveness has been established.
There are some small, positive studies—such as mild fatigue improvement
(Med Gas Res, 2021; 11: 73–79)—
but all are small-scale and have weak placebo controls.
For athletes, evidence is especially limited regarding:
• Muscle recovery
• Performance enhancement
• Injury healing
“An athlete uses it” ≠ “It works.”
Athletes often try new devices regardless of rigorous scientific validation.
4. What about “hydrogen spas” and “hydrogen baths”?
Can hydrogen in water pe*****te the skin?
This is a common misunderstanding.
The skin barrier is extremely strong.
There is no evidence that hydrogen pe*****tes the skin in amounts significant enough to affect the whole body.
If substances easily passed through the skin, the skin would not protect us—and daily bathing would be dangerous.
Moreover, hydrogen gas escapes water quickly due to its volatility.
So, does hydrogen have no potential?
→ Not at all.
Hydrogen’s potential in:
• Antioxidant effects
• Anti-inflammatory effects
• Gene expression regulation
…is scientifically intriguing.
However, as a physician, I must say honestly:
At present, it remains an “adjunct therapy.”
There isn’t enough evidence to make it a main treatment or cornerstone of anti-aging medicine.
That said, relaxation and mood-improving effects are very plausible—likely enhanced by placebo effects as well.
Summary
Claims that hydrogen “works” require caution—but its research potential should not be dismissed.
Lung breathing functions by negative pressure, and unlike oxygen, hydrogen has no equivalent to hemoglobin. Diffusion driven by partial pressure is minimal. This is a medically sound perspective.
My own stance is:
I cannot yet say hydrogen inhalation “changes the whole body.”
Still, because basic research is progressing,
the medical approach is to maintain “cautious optimism” while awaiting future clinical evidence.
