Allergy
For allergic diseases, the human data situation is limited: only a few small human studies exist — for example on allergic rhinitis and skin reactions — supplemented by reviews and predominantly preclinical investigations in animal and cell models (e.g. on allergic asthma).
The studies examined hydrogen-rich water, H₂ inhalation, hydrogen-rich saline and topical applications. Endpoints were inflammatory and immunological markers as well as individual symptom parameters; mechanistically, H₂ is regarded as a possible damper of allergic inflammatory responses.
The few human findings are preliminary and rely heavily on preclinical models. Robust statements about a clinical benefit in allergies are currently not possible; H₂ is not a recognized allergy treatment.
Human studies on molecular hydrogen for Allergy. This page collects the 13 studies catalogued in this area — 2 randomized trials, 2 pilot/observational studies and 6 reviews. Listed newest first.
2025 · Zajac — Molecular Hydrogen in the Treatment of Respiratory Diseases
This review compiles twenty years of research on molecular hydrogen in respiratory medicine, covering allergies, asthma, COPD, pulmonary fibrosis, lung injury, respiratory infections, and lung cancer.
2021 · Bajgai et al. — Role of Molecular Hydrogen in Skin Diseases and its Impact in Beauty.
Oxidative stress and chronic inflammation are central drivers of skin diseases such as psoriasis, atopic dermatitis, and skin ageing; molecular hydrogen (H₂) may offer a therapeutic approach by targeting these mechanisms.
2021 · Ohta — Direct Targets and Subsequent Pathways for Molecular Hydrogen to Exert Multiple Functions: Focusing on Interventions in Radical Reactions
Molecular hydrogen (H₂) is not simply a passive antioxidant — it actively intervenes in radical chain reactions, modifying lipid peroxides and downstream signaling cascades.
2015 · Ohta — Molecular hydrogen as a novel antioxidant: overview of the advantages of hydrogen for medical applications.
Molecular hydrogen (H₂) is a mild, selective antioxidant that neutralizes the most damaging reactive oxygen species without disrupting normal cellular redox signaling — a key advantage over broad-spectrum antioxidants.
2012 · Ohta — Molecular hydrogen is a novel antioxidant to efficiently reduce oxidative stress with potential for the improvement of mitochondrial diseases.
This review by Shigeo Ohta — one of the founders of modern H₂ medicine — surveys the biological effects of molecular hydrogen across more than 38 diseases, physiological states, and clinical tests documented in the years following the 2007 Nature Medicine paper.
2011 · Ohta — Recent progress toward hydrogen medicine: potential of molecular hydrogen for preventive and therapeutic applications.
Since the landmark 2007 Nature Medicine paper demonstrating that molecular hydrogen (H₂) selectively neutralizes toxic hydroxyl radicals, the field of hydrogen medicine has grown rapidly.
2020 · Jin — Changes of nasal nitric oxide in the treatment of allergic rhinitis with hydrogen-rich saline lavage of nasal cavity
A nasal lavage with hydrogen-rich saline significantly changed the nitric-oxide value in the nose and could thus offer a starting point for treating allergic rhinitis (hay fever).
2018 · Jin — Clinical Study of Hydrogen-Rich Saline in the Treatment of Moderate to Severe Allergic Rhinitis
Nasal lavage with hydrogen-rich saline significantly improved symptoms, signs, and quality of life in patients with moderate-to-severe allergic rhinitis — with no relevant adverse effects.
2025 · Wong et al. — Nano-Bubble Hydrogen Water in Wet-Wrap Dressing Improves the Severity of Pediatric Patients With Atopic Dermatitis
In 20 children with atopic dermatitis, wet-wrap dressings soaked in nano-bubble hydrogen water significantly reduced erythema, dryness, and total skin severity scores compared to baseline; in a split-body sub-study (8 patients), hydrogen-water-treated limbs improved significantly more than limbs treated with plain water.
2005 · Sobko et al. — Birth-Related Increase in Intracolonic Hydrogen Gas and Nitric Oxide as Indicator of Host-Microbial Interactions
This study measured endogenous hydrogen gas produced by gut bacteria in 32 newborns during the first 6 months of life to monitor intestinal colonization — it is not an H₂ therapy study.
2021 · Zhang — Molecular hydrogen alleviates asthma through inhibiting IL-33/ILC2 axis
In an OVA-sensitised mouse model of asthma and a bronchial epithelial cell model, hydrogen/oxygen gas mixture inhalation markedly reduced allergic inflammation by suppressing the IL-33/ILC2 signalling axis.
2020 · Niu — Hydrogen Attenuates Allergic Inflammation by Reversing Energy Metabolic Pathway Switch
Hydrogen curbs allergic airway inflammation by resetting a disturbed energy metabolism of the immune cells.
2017 · Zhao — Changes in IL-4 and IL-13 Expression in Allergic Rhinitis Treated with Hydrogen-Rich Saline in a Guinea-Pig Model
Hydrogen-rich saline significantly reduced sneezing, scratching, IgE levels, and key allergy-driving cytokines (IL-4, IL-13) in guinea pigs with experimentally induced allergic rhinitis.