Molecular Hydrogen Therapy: Evidence Review and the Science Behind (2023)

We were sceptical about molecular hydrogen until we did our own research. Surprisingly, scientific studies revealed that a simple molecule like hydrogen has antioxidant benefit and is able to protect cells against free radicals. Let's check out the science and evidence behind this.

As of October 2023, a search on the US National Library of Medicine will show over 3,000 published papers on "molecular hydrogen" in health and wellness and more than 1,000 on-going studies related to "molecular hydrogen" on

Hydrogen medicine is a new and dynamic field with many on-going research. This list is a work-in-progress list as new evidence might be added from time to time.

This work-in-progress article has more than 150 references and supporting studies related to molecular hydrogen.

molecular hydrogen therapy

What Is Hydrogen Water?

Is hydrogen water a scam? Hydrogen (H2) is the most abundant molecule in the Universe. As you know, it’s also an odorless, colorless, and tasteless gas.

Published in 1988, the association between high dietary fibre intakes and reduced disease incidence was studied. It was proposed that molecular hydrogen (acting as a powerful antioxidant), produced in quite large amounts as a by-product of colonic fermentation of dietary fibre and unabsorbed carbohydrate may play an important role (Med Hypotheses. 1988).

In 2007 and reported in a reputable journal (Nature Medicine. 2007) by a team in Japan, discovered that inhaled hydrogen gas could act as an antioxidant and protect the brain from free radicals. This sparked the interest in its potential health benefits worldwide and led to many published and on-going clinical research.

Following the landmark publication in Nature Medicine in 2007, many other studies regarding the potential application of hydrogen therapy on various conditions were subsequently published. Since the Japanese discovery, the effects of hydrogen have been researched in 63 diseases [Ref]!

It’s less known that hydrogen was therapeutically used for the first time in humans in the early 90s. It was given to 3 divers to successfully help them overcome the effects of high pressure on the brain in deep-sea diving [R, R].

Hydrogen is the smallest existent gas molecule. Because of this unique property, molecular hydrogen could penetrate into virtually every organ and cell in the body (including the brain) where it may have antioxidant, anti-inflammatory, weight-loss, and anti-allergy activity. Molecular hydrogen seems like the perfect therapeutic the world has been eagerly searching for – with very few known side effects and such wide-ranging action [R, R].

Hydrogen water is loaded with hydrogen molecules. It was formulated as the most practical and easy way to get hydrogen into the whole body. But it’s not the only way – hydrogen can also be inhaled, injected, or absorbed through a bath [R].

Hydrogen Water and Molecular Hydrogen Research by Category

Here, we have listed and compiled all other significant scientific publications related to hydrogen water and hydrogen molecule. The list was complied by running various searches on PubMed. Each study and is hyperlinked to the abstract in the U.S. National Library of Medicine or the full text article.

Here is the list by category.

1) Long COVID

Griffith University researchers (Mar 2023) identify similar brain structure changes in both chronic fatigue syndrome and long COVID. According to the researchers:

The symptom overlap between ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) and long COVID patients is consistent with our current findings of similar abnormalities in the brainstem.

Published in April 2022, this literature review suggested that Hydrogen gas may be an effective medical gas for the treatment of Chronic Fatigue Syndrome.

Published in February 2022 (Int J Environ Res Public Health. 2022), this randomised controlled trial concluded that Hydrogen gas inhalation had beneficial health effects in terms of improved physical and respiratory function in acute post-COVID-19 patients.

Explore more related articles: Long COVID

2. Molecular Hydrogen and Cancer

There are more than 600 search results on molecular hydrogen and cancer, based on articles retrieved from PubMed, Google Scholar and Cochrane.

Published in the Asian Pacific Journal of Cancer Prevention in 2023, this systematic review is the first to summarise effects associated with the use of molecular hydrogen for cancer. Out of the 677 articles retrieved from Cochrane, PubMed and Google Scholar, 27 articles were included for this systematic review. Based on the authors' analysis, "H2 plays a promising therapeutic role as an independent therapy as well as an adjuvant in combination therapy, resulting in an overall improvement in survivability, quality of life, blood parameters, and tumour reduction."

3. Antioxidant, Ischaemia-Reperfusion Injury and Brain-Protective Effects 

It was first shown in 2007 that molecular hydrogen (H2) could protect cells from damage by reducing reactive oxygen species (ROS). Inhaled hydrogen also easily reached the brain to reduce injury in rats with stroke [Nat Med. 2007].

In 2009, it was shown that hydrogen water prevented cognitive, learning, and memory problems in mice under stress by acting as an antioxidant. It also protected cells in the brain’s memory hub from
the detrimental effects of stress [Neuropsychopharmacology. 2009].

In the first pilot study of 38 stroke patients (2013), a hydrogen solution (IV) was safe and had a mild antioxidant effect [ref].

In 2017, one randomised controlled study assessing the effectiveness and safety of Hydrogen Gas inhalation treatment in stroke patients was published. Hydrogen gas inhalation treatment was safe and effective in patients with acute stroke (cerebral infarction) [Ref].

In 2019, a study on performed in a large animal model, suggests that adding hydrogen to the usual mix of respiratory gases could further protect babies' brains. The study was published in the Journal of the American College of Cardiology (JACC): Basic to Translational Science. The research team includes medical scientists from Harvard Medical School and Boston Children's Hospital United States.

Inhalation of hydrogen gas in patients with PCAS (post cardiac arrest syndrome) was approved as advanced medical care by the Ministry of Health, Labour and Welfare of Japan in November 2016 (Acute Med Surg. 2018). The study protocol for a randomized controlled trial was published as “Efficacy of inhaled HYdrogen on neurological outcome following BRain Ischemia During post-cardiac arrest care (HYBRID II trial)” (Trials. 2017).

Related: Why Molecular Hydrogen is a superior anti-oxidant?

4. Parkinson Disease

In 2013, another small study of 17 patients with Parkinson’s disease was published. Those who drank hydrogen water had improved symptoms. Those who drank regular “placebo” water, however, experienced a worsening. There were also no adverse effects to drinking 1 L of hydrogen water daily for almost one year [ref].

Led by the same lead author, the results of the pilot study will be confirmed in this longer and larger-scale study that includes patients who are not medicated with levodopa. This study will confirm the safety and tolerability of H2-water and if H2-water can improve Parkinson Disease symptoms.

5. Side Effects of Chemotherapy and Radiation (Chemo and Radio-protective)

Published in August 2020 (Biomed Pharmacother. 2020), this article reviewed up to date medical progress related to H2 as a radioprotectant, covering its unique properties, potential mechanisms of action, delivery techniques, findings in vitro/vivo studies even clinical practice. 

Presently ionizing radiation (IR) has extensive applications in medical diagnostics (e.g. CT scan) and tumor therapy (e.g.Radiotherapy). There has always been a strong demand for safe and potent radioprotectants. The only U.S. FDA approved radioprotectant available today is the synthetic thiol amifostine. However, it has many shortcomings such as short protection time, unfavorable routes of administration, and comparatively high toxicity. Natural antioxidants such as melatonin, vitamin E, and others, while having fewer adverse effects, they also offer much weaker protection compared against thiol agents. H2 can be easily applied with little adverse effects and great efficacy as a potential radioprotective agent. 

In 2011, a study of 49 patients (published in 2011) on radiation therapy for liver cancer, drinking hydrogen water (1.5 – 2 L/day) improved the patients’ quality of life and appetite. Hydrogen water could reduce oxidative stress and damage from radiation without compromising its cancer-killing effects [R].

In 2017, a study (published in the Molecular and Clinical Oncology), evaluated the protective effect of hydrogen-rich water on liver function of colorectal cancer patients treated with chemotherapy in 152 patients. The hydrogen-rich water group exhibited protective effect against the chemotherapy related liver injury [R].

6) Diabetes and Metabolic Syndrome (Hydrogen Water for Endocrine Disorders)

Published in 2008, a study showed that drinking hydrogen water decreased cholesterol, improved glucose tolerance and insulin resistance in 36 patients with type 2 diabetes or pre-diabetes (impaired glucose tolerance). The patients drank 900 mL of hydrogen water daily for 8 weeks [R].

In another pilot study published in 2010, patients prone to metabolic syndrome drank hydrogen water (1.5 – 2 L/day) for 8 weeks. Subjects demonstrated an 8% increase in HDL-cholesterol (good cholesterol) and a 13% decrease in total cholesterol from baseline to week 4 [R].

Further, subjects demonstrated an 8% increase in high density lipoprotein (HDL)-cholesterol and a 13% decrease in total cholesterol/HDL-cholesterol from baseline to week 4.

7) Eye Injuries

In acute glaucoma of the eyes, transient elevation of intra-ocular pressure causes significant reductions in the thickness of the retina by injury mediated through the generation of free radicals. Hydrogen-loaded eye drops aided the recovery of eye injuries in rats. It protected the nerves in the eye by its antioxidant action [ref].

A hydrogen solution reduced detrimental blood vessel growth in mice with eye injuries from chemicals. Hydrogen solutions could be used as a first-aid rinse to prevent blindness from chemical burns [ref].

8) Lungs

In a study published in 2016, 96 workers exposed to haze were randomised to 2 groups; the treatment group inhaled hydrogen and oxygen mixture (66.67%∶33.33%) 1 hour per day for 30 days, while the control group inhaled nitrogen and oxygen mixture (66.67%∶33.33%) 1 hour per day for 30 days.

The study concluded that inhalation of hydrogen gas could protect lungs of sanitation workers exposed to air pollution. Importantly, inhalation of hydrogen could improve respiratory symptoms such as cough as well.

9) Suppressing Inflammation and joint disorders

PubMed has indexed more than 11,000 research studies on molecular hydrogen and anti-inflammatory

In one human study, 20 patients with rheumatoid arthritis drank 0.5 L/day of hydrogen water for 4 weeks. By the end of the study, all patients with early rheumatoid arthritis achieved remission and
20% became symptom-free [R, R].

10) Muscle Fatigue and Weakness

In an experiment with 10 young athletes (DB-CT), drinking hydrogen water reduced lactic acid build-up during heavy exercise and decreased muscle fatigue [R].

Drinking 2 L of hydrogen water daily helped 8 cyclists power through sprints with more energy and less exhaustion in one small 2-week study [R].

11) Hydrogen Water Enhances Energy Metabolism

Drinking hydrogen water protected the body’s energy powerhouse, the mitochondria, in several studies of 41 people with muscle diseases. They drank 0.5 – 1 L of hydrogen water per day [R].

12) Boosts Skin Health

Hydrogen water given through an IV solution safely improved skin health in 4 patients with skin redness and inflammation, and pain. The skin redness went away after a couple of days of treatment and did not come back [R].

Bathing in hydrogen water for 3 months noticeably reduced skin wrinkles in 6 people. Hydrogen water could also boost collagen production, reduce UV damage and act as an antioxidant in skin cells. Warm hydrogen-infused baths could be a pleasant, safe way to reverse skin aging [R].

In a study published in Nature in 2018, hydrogen-water bathing therapy could fulfill the unmet need for chronic inflammatory skin diseases such as psoriasis after 8 weeks of treatment.

13) Anti-aging and Longevity

Ageing is a physiological process of progressive decline in the organism function over time. It affects every organ in the body and is a significant risk for chronic diseases. PubMed has indexed more than 700 research studies on molecular hydrogen and anti-aging.

This paper (Mar 2022) reviews the basic research and recent application of hydrogen in order to support hydrogen use in medicine for ageing prevention and ageing-related disease therapy.

Molecular hydrogen has therapeutic and preventive effects on various organs. It has antioxidative properties as it directly neutralizes hydroxyl radicals and reduces peroxynitrite level. It also activates Nrf2 and HO-1, which regulate many antioxidant enzymes and proteasomes. Through its antioxidative effect, hydrogen maintains genomic stability, mitigates cellular senescence, and takes part in histone modification, telomere maintenance, and proteostasis. In addition, hydrogen may prevent inflammation and regulate the nutrient-sensing mTOR system, autophagy, apoptosis, and mitochondria, which are all factors related to ageing. Hydrogen can also be used for prevention and treatment of various ageing-related diseases, such as neurodegenerative disorders, cardiovascular disease, pulmonary disease, diabetes, and cancer. 

It was also already discovered that hydrogen can prolong the life of stem cells by reducing oxidative stress [R].

14) Enhances Wound Healing

Hydrogen water intake via tube feeding in elderly patients reduced the wound size of pressure ulcers and enhanced recovery [R].

15) May Improve Bladder Health

In rats with a blockage in the bladder, drinking hydrogen water reduced bladder volume by neutralising oxidative stress. It also improved the responsiveness of bladder muscles. As a strong antioxidant, hydrogen water could potentially help those with a bladder obstruction [R].

16) May Protect the Kidneys

Hydrogen added to the dialysis solution reduced inflammation and high blood pressure in 21 kidney failure patients on dialysis [R].

17) May Protect the Liver

In 60 patients with Hepatitis B (a viral infection that attacks the liver and can cause both acute and chronic disease), drinking hydrogen water as an add-on to regular treatment was safe and reduced oxidative stress [R].

Hydrogen water also significantly improved liver function and reduced oxidative stress in patients with chronic hepatitis B [R].

18) May Kill Bacteria and Improve Oral Health

Drinking hydrogen water 4 – 5X daily improved gum health in 13 patients with inflamed gums after 8 weeks. It also boosted blood antioxidants and enhanced the effects of other gum disease treatments [R].

Hydrogen water could kill the bacteria that most commonly cause gum disease and cavities. It could be used to improve overall oral health [R].

19) Preserves Transplant Organs

Hydrogen water could help preserve and reduce damage to transplant organs without any toxic effects. It reduced the inflammation and injury that usually happens when donated organs are stored, which could help save more lives [R].

20) Infectious Disease (Influenza and other viral infectious diseases)

A group of scientists in China suggested that hydrogen-rich solution therapy may be a safe, reliable, and effective treatment for Multiple Organ Dysfunction Syndrome (MODS) induced by influenza and other viral infectious diseases (SOJ Microbiol Infect Dis. 2017).

Hydrogen Water Safety, Dosage, Side effects

Experts don’t believe there are any risks to drinking hydrogen water (WebMD). Drinking too much water poses the risk of a life hyponatremia. This occurs when your kidneys can’t get rid of excess water and the sodium content in your blood is diluted. Hyponatremia can be life-threatening. However, you need to drink a lot of water for hyponatremia to occur. Usually only athletes performing intense exercise are at risk.

Molecular hydrogen (H2) has no known side effects. It’s not toxic even at high concentrations. However, the long-term risks remain unknown until additional studies are carried out [R].

In most clinical studies, people drank 0.5 – 2 L of hydrogen water daily.

After drinking hydrogen water, about 40% of the H2 is absorbed by the body [R].

Where to buy hydrogen water?

There are many hydrogen water related products you can buy online. Shop for hydrogen water online > Amazon.

Explore more related articles: Molecular Hydrogen


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