Top Clinical Studies on Molecular Hydrogen

Hydrogen acts as a therapeutic antioxidant by selectively reducing cytotoxic oxygen radicals

Ohsawa I, Ishikawa M, Takahashi K, et al.

Nature Medicine · 2007 · PMID: 17486089

The foundational paper for the entire field. Showed H₂ selectively reduces hydroxyl radicals (•OH) and peroxynitrite — the most cytotoxic species in cellular oxidative stress — while leaving beneficial reactive oxygen species intact. Cited 2,000+ times in the subsequent literature.

In vitro + animal model (rat middle cerebral artery occlusion)

Recent progress toward hydrogen medicine: potential of molecular hydrogen for preventive and therapeutic applications

Ohta S.

Current Pharmaceutical Design · 2011 · PMID: 21219114

Comprehensive mechanism review establishing molecular hydrogen as a non-classical antioxidant with disease-modifying potential across multiple inflammatory and metabolic conditions. Surveys the early human and animal evidence and outlines the proposed selective-radical-scavenging mechanism.

Beneficial biological effects and the underlying mechanisms of molecular hydrogen — comprehensive review of 321 original articles

Ichihara M, Sobue S, Ito M, et al.

Medical Gas Research · 2015 · PMID: 31958022

Systematic review covering 170+ disease models — including inflammatory, metabolic, neurological, and oxidative-stress conditions — where molecular hydrogen has been investigated for preventive and therapeutic effects. Discusses delivery routes, dosing, and mechanism-of-action evidence to date.

Supplementation of hydrogen-rich water improves lipid and glucose metabolism in patients with type 2 diabetes or impaired glucose tolerance

Kajiyama S, Hasegawa G, Asano M, et al.

Nutrition Research · 2008 · PMID: 18707463

Randomized, double-blind, placebo-controlled crossover pilot. 30 patients with type-2 diabetes or impaired glucose tolerance drank 900 mL of hydrogen-rich water daily for 8 weeks. Researchers observed changes in oxidative-stress markers, lipid profile, and adiponectin levels in the hydrogen arm versus placebo.

N=30 · 8-week crossover · double-blind, placebo-controlled

Consumption of water containing a high concentration of molecular hydrogen reduces oxidative stress and disease activity in patients with rheumatoid arthritis

Ishibashi T, Sato B, Rikitake M, et al.

Medical Gas Research · 2012 · PMID: 22520831

Open-label pilot study of 20 patients with rheumatoid arthritis drinking high-concentration hydrogen water (4–5 ppm, 530 mL/day) for 4 weeks. Researchers observed changes in oxidative-stress markers (8-OHdG) and reported disease-activity scores (DAS28) over the intervention period.

N=20 · 4-week pilot · open-label

Consumption of water containing over 3.5 mg of dissolved hydrogen could improve vascular endothelial function

Sakai T, Sato B, Hara K, et al.

Vascular Health and Risk Management · 2014 · PMID: 25378931

Open-label trial in 34 adults assessing flow-mediated dilation (FMD) of the brachial artery before and after drinking high-concentration hydrogen water. Researchers reported changes in endothelial function — a surrogate marker linked to long-term cardiovascular health.

N=34 · open-label

Pilot study of H₂ therapy in Parkinson’s disease: a randomized double-blind placebo-controlled trial

Yoritaka A, Takanashi M, Hirayama M, et al.

Movement Disorders · 2013 · PMID: 23400965

48-week randomized, double-blind, placebo-controlled pilot in levodopa-treated Parkinson’s patients drinking 1,000 mL/day of hydrogen-rich water. Researchers tracked Unified Parkinson’s Disease Rating Scale (UPDRS) scores between the hydrogen and placebo arms.

N=17 · 48 weeks · randomized, double-blind, placebo-controlled

Hydrogen-rich water consumption positively affects muscle performance, lactate response, and alleviates delayed-onset muscle soreness after resistance training

Botek M, Krejčí J, McKune AJ, Sládecčková B.

Journal of Strength and Conditioning Research · 2022 · PMID: 33555824

Randomized, double-blind, placebo-controlled crossover trial in resistance-trained men. Participants consumed hydrogen-rich water before exercise; researchers measured blood lactate, countermovement-jump performance, and delayed-onset muscle soreness (DOMS) ratings versus placebo.

N=12 · crossover · randomized, double-blind, placebo-controlled

Hydrogen-rich water reduces liver fat accumulation and improves liver enzyme profiles in patients with non-alcoholic fatty liver disease: a randomized controlled pilot trial

Korovljev D, Stajer V, Javorac D, Ostojić SM.

Irish Journal of Medical Science · 2019 · PMID: 30982748

28-day randomized controlled pilot trial in overweight outpatients with non-alcoholic fatty liver disease drinking 1 L/day of hydrogen-rich water versus placebo. Researchers used dual-echo MRI to assess liver fat and measured liver enzyme (AST/ALT) profiles before and after the intervention.

N=12 · 28-day pilot · randomized, controlled

The effects of 24-week, high-concentration hydrogen-rich water on body composition, blood lipid profiles, and inflammation biomarkers in adults with metabolic syndrome

LeBaron TW, Singh RB, Fatima G, et al.

Diabetes, Metabolic Syndrome and Obesity · 2020 · PMID: 32273740

Randomized, double-blind, placebo-controlled trial in adults with metabolic syndrome. Over 24 weeks, researchers tracked body composition, blood lipids, HbA1c, glucose, and inflammation biomarkers between the hydrogen and placebo arms.

N=60 · 24 weeks · randomized, double-blind, placebo-controlled