How has molecular hydrogen been studied in respiratory conditions?

60 people with post COVID-19 syndrome were randomized to nitric oxide plus hydrogen, nitric oxide alone or control, 20 per group. Inhalation lasted 90 minutes daily for ten days; respiratory symptoms, walking and microcirculation were assessed.

Ter Arkh · 2026 · PMID 41859790

100 people with COPD exacerbation, respiratory failure and pulmonary hypertension after COVID-19 were randomized to five groups. Combinations of thermal helium and oxygen, nitric oxide and hydrogen were compared with a control alongside noninvasive ventilation and existing medication.

Ter Arkh · 2025 · PMID 40327618

675 COVID-19 outpatients were followed in a triple blind randomized study of hydrogen rich water or placebo twice daily for 21 days; clinical changes and adverse events were recorded through day 30.

J Clin Med · 2024 · PMID 39124575

32 participants with Long COVID were randomized under single blinding to hydrogen rich water or placebo water, 16 per group, for 14 days; fatigue, dyspnea, walking, chair stands and sleep questionnaires were compared.

Nutrients · 2024 · PMID 38794767

64 people with Omicron COVID-19 were randomized to hydrogen and oxygen inhalation or oxygen, 32 per group; viral testing, IL-6, lymphocytes and lung imaging were followed.

J Clin Biochem Nutr · 2023 · PMID 37970554

120 people with chronic rhinitis were randomized under double blinding to hydrogen rich saline or normal saline nasal irrigation; symptoms, nasal secretions, nitric oxide and regulatory immune cells were compared, with allergic and nonallergic subgroups.

J Inflamm Res · 2022 · PMID 35873384

50 symptomatic adults 21 to 33 days after a positive COVID-19 test were randomized under single blinding to hydrogen or placebo inhalation for 60 minutes twice daily for 14 days; lung function and six minute walking were measured.

Int J Environ Res Public Health · 2022 · PMID 35206179

People with acute COPD exacerbation at ten centers were randomized under double blinding to a hydrogen and oxygen mixture or oxygen; symptom scores and adverse events were recorded for seven days. Sample size is not stated in the abstract.

Respir Res · 2021 · PMID 33985501

20 people with moderate or severe persistent allergic rhinitis entered a randomized double blind self controlled comparison of hydrogen rich saline and normal saline nasal irrigation; nasal nitric oxide was measured weekly.

Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi · 2020 · PMID 32791592

20 people with moderate or severe allergic rhinitis underwent a randomized double blind self controlled comparison of hydrogen rich saline and normal saline nasal irrigation; symptom and examination scores and quality of life questionnaires were assessed.

Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi · 2018 · PMID 29798076

34 people with post COVID-19 syndrome were compared in nitric oxide plus hydrogen inhalation and no inhalation groups, 17 per group. Sessions lasted 90 minutes daily for ten days; symptoms, walking and microcirculation were assessed. Randomization is not described.

Ter Arkh · 2024 · PMID 38713041

A retrospective study of 180 hospitalized COVID-19 records used propensity matching to compare 33 hydrogen and oxygen recipients with 55 oxygen recipients; hospital stay, discharge and oxygen saturation were examined.

BMC Infect Dis · 2023 · PMID 37386364

60 healthcare workers recovering from COVID-19 were compared: 30 received 90 minute hydrogen inhalation and 30 received existing care. Immunoglobulins and phagocytosis in nasal, pharyngeal and blood samples were measured on days one and ten. Randomization is not described.

Ter Arkh · 2022 · PMID 36286901

Hospital records of 12 COVID-19 patients receiving existing care and 12 receiving additional hydrogen and oxygen inhalation were compared retrospectively; blood, inflammatory, electrolyte, liver and kidney measurements were reviewed.

Medicine (Baltimore) · 2022 · PMID 35244034

Symptoms, IgE, eosinophils and nasal microbiota were compared before and after hydrogen inhalation in people with allergic rhinitis; healthy participants were also included in microbiota analysis. Sample size is not stated in the abstract.

World Allergy Organ J · 2024 · PMID 39308790

Six people with COPD inhaled hydrogen for 30 minutes three times daily for 30 days alongside existing care; symptoms, lung function, sleep and blood markers were measured before and after.

Medicina (Kaunas) · 2024 · PMID 38399533

Ten people with chronic lung disease, seven with COPD, two with asthma and one with pulmonary tuberculosis, drank hydrogen rich water for four weeks; oxygen saturation, blood pressure, oxidative markers and exercise observations were recorded without a control group.

Diseases · 2023 · PMID 37873771

Ten people with asthma and ten with COPD inhaled a steam gas mixture containing 2.4% hydrogen once for 45 minutes; inflammatory markers in blood and exhaled breath condensate were compared before and after.

QJM · 2020 · PMID 32407476

One patient with COVID-19 like symptoms drank hydrogen rich water in a case report; oxygen status and exercise capacity were recorded. Dose and duration are not stated in the abstract.

Clin Case Rep · 2021 · PMID 34765212

A narrative review of three hydrogen papers on COPD, separating one animal experiment, one prospective clinical study and one randomized trial.

Open Med (Wars) · 2026 · PMID 42164762

A systematic review and network meta analysis of nasal irrigation for allergic rhinitis, covering 23 studies and 3,584 participants; hydrogen rich water is one of several irrigants.

Front Pharmacol · 2025 · PMID 41293244

A review of preclinical and clinical hydrogen gas and fluid research in critical illness, including lung injury and sepsis. The abstract does not state an included study count.

Intensive Care Med Exp · 2025 · PMID 40938520

A review of molecular hydrogen literature on respiratory conditions including allergy, asthma, COPD and lung injury. The abstract does not state an included study count.

Int J Mol Sci · 2025 · PMID 40362357

A review of hydrogen inhalation, drinking water and saline literature and cellular pathways, with a focus on COVID-19. The abstract does not state an included study count.

Biomedicines · 2023 · PMID 37509530

A rapid review of pharmacological and inhaled interventions for post COVID-19 condition, identifying five completed and 41 ongoing studies, including hydrogen inhalation.

Cochrane Evid Synth Methods · 2023 · PMID 40475898

A systematic review of 20 post COVID-19 fatigue studies with 5,629 participants, including hydrogen inhalation among several interventions.

Front Psychiatry · 2022 · PMID 36032234

A review of molecular hydrogen research in acute lung injury, describing delivery routes and measured inflammatory and cell death pathways. The abstract does not state an included study count.

Mol Med · 2022 · PMID 35240982

A review of experimental and clinical hydrogen literature on lung injury, COPD, asthma, pulmonary fibrosis and related conditions. The abstract does not state an included study count.

J Zhejiang Univ Sci B · 2022 · PMID 35187885

A review of molecular hydrogen literature in COVID-19 and critical illness, including hydrogen and oxygen inhalation and inflammation experiments. The abstract does not state an included study count.

Front Med (Lausanne) · 2021 · PMID 34746162

A review of preclinical and clinical molecular hydrogen research relevant to COVID-19, covering measured oxidative, inflammatory and cell death pathways. The abstract does not state an included study count.

Oxid Med Cell Longev · 2021 · PMID 34646423

A review of hydrogen literature in lung transplantation, describing inhalation, drinking water, infusion, organ preservation and experimental measurements. The abstract does not state an included study count.

Exp Biol Med (Maywood) · 2021 · PMID 33899545

A review of hydrogen experimental literature including radiation lung injury, covering gas inhalation and hydrogen water in cells and animals. The abstract does not state an included study count.

Curr Pharm Des · 2021 · PMID 33463456

A narrative review of existing molecular hydrogen research relevant to COVID-19; it did not recruit a new participant cohort. The abstract does not state an included study count.

Front Pharmacol · 2020 · PMID 33178011

Mice with acute lung injury received methylprednisolone nanoparticle nebulization carried by hydrogen and oxygen gas; a gas only arm was also included. Aerosol distribution, lung tissue and inflammatory markers were measured. Sample sizes are not stated in the abstract.

Int J Pharm · 2026 · PMID 42951223

Mice with ovalbumin induced asthma inhaled hydrogen for seven days; airway responsiveness, histology, immune and oxidative markers were measured. Sample sizes are not stated in the abstract.

Eur J Med Res · 2025 · PMID 41146240

Mice with traumatic brain injury inhaled 2% hydrogen for 60 minutes at one and six hours after injury; lung tissue, oxygenation and NLRP3 markers were assessed, including an inhibitor combination arm. Sample sizes are not stated in the abstract.

BMC Chem · 2025 · PMID 40405232

Mice with pemphigus associated interstitial lung disease received hydrogen rich water; lung tissue, inflammatory genes and oxidative markers were assessed. Sample sizes are not stated in the abstract.

Int J Mol Sci · 2025 · PMID 40362440

150 mice with blast lung injury were assigned to nebulized hydrogen rich water or sterile water, 75 per group; lung function, blood gases and histology were compared at 6, 12, 24 and 48 hours after injury.

Surgery · 2025 · PMID 39799761

Rats with cigarette smoke induced COPD received a hydrogen and oxygen generator intervention or steroid; blood cells, lung structure and echocardiography were compared. Sample sizes are not stated in the abstract.

Curr Res Toxicol · 2024 · PMID 39839142

30 mice in an ovalbumin asthma experiment were randomized to five groups; 3% hydrogen inhalation, salbutamol and control conditions were compared using lung histology, blood cells, immune and oxidative markers.

Antioxidants (Basel) · 2024 · PMID 39594470

Protein and metabolite profiles were analyzed after hydrogen inhalation in septic mice; separate cell and animal experiments assessed a microalgae carried composite that generates hydrogen. Sample sizes are not stated in the abstract.

Mater Today Bio · 2024 · PMID 39328786

Asthmatic mice received hydrogen rich water and underwent gut microbiota and serum metabolite analysis; additional cell work examined indole acetic acid and AhR signaling. Sample sizes are not stated in the abstract.

Free Radic Biol Med · 2024 · PMID 39147072

Mice with an acute respiratory distress model received hydrogen carrying coral calcium or hydrogen inhalation; lung function, microcirculation and mitochondrial division pathways were compared. Sample sizes are not stated in the abstract.

J Pharm Anal · 2024 · PMID 40177064

Mice with radiation lung injury received different cycles of hydrogen inhalation; lung function, histology, macrophages and NF-κB signaling were measured. Sample sizes are not stated in the abstract.

Heliyon · 2024 · PMID 38826750

18 rats were assigned to control, hindlimb ischemia reperfusion, or ischemia reperfusion plus hydrogen saline; saline was injected intraperitoneally 30 minutes before ischemia, with lung histology and oxidative markers compared.

Sci Prog · 2024 · PMID 38807538