Molecular hydrogen as a treatment for ME/CFS: a mini-review of clinical evidence and mechanistic rationale

Abstract:

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a debilitating multisystem illness characterized by profound fatigue, post-exertional malaise, cognitive impairment, and autonomic dysfunction, yet it currently lacks FDA-approved treatments. Molecular hydrogen (H2), administered primarily as hydrogen-rich water (HRW), has emerged as a potential therapeutic candidate due to its selective antioxidant effects, anti-inflammatory activity, and support of mitochondrial and cellular homeostasis. These mechanisms align with several biological abnormalities implicated in ME/CFS, including oxidative stress, chronic inflammation, and impaired energy metabolism. This narrative mini-review summarizes mechanistic evidence relevant to ME/CFS and evaluates three developmental clinical studies of HRW in this population.

Although early trials are small and methodologically limited, moderate-dose HRW consumed over extended durations has demonstrated feasibility and preliminary benefits in reducing fatigue and improving physical function, with generally mild side effects. Overlapping findings in Long COVID further suggest potential applicability across related post-viral fatigue conditions. Key limitations include small sample sizes, reliance on self-report outcomes, and the absence of objective biomarkers.

Future research should prioritize larger, rigorously controlled trials incorporating remote biometric and biochemical assessments to clarify mechanisms of action and identify responsive subgroups. Overall, molecular hydrogen represents a promising, low-burden adjunctive therapy warranting further investigation in ME/CFS.

Source:Friedberg F and LeBaron TW (2026) Molecular hydrogen as a treatment for ME/CFS: a mini-review of clinical evidence and mechanistic rationale. Front. Med. 13:1760210. doi: 10.3389/fmed.2026.1760210 https://www.frontiersin.org/journals/medicine/articles/10.3389/fmed.2026.1760210/full (Full text)

Successful treatment of myalgic encephalomyelitis/chronic fatigue syndrome using hydrogen gas: four case reports

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is characterized by unexplained fatigue and malaise that persist for more than 6 months with neuropsychiatric symptoms, including slight fever, headache, weakness, impaired thinking, and depression.[1,2] The onset and severity of these symptoms vary and reduce the quality of life as well as social, occupational, and personal activities of those affected, with some becoming bedridden.[1,2] The number of ME/CFS patients in the United States is estimated to be between 836,000 and 2.5 million.[3]

Although it currently remains unclear whether there are objective and biological abnormalities in ME/CFS, recent neuroimaging, blood marker analyses, and energy metabolism and mitochondrial studies detected these abnormalities in ME/CFS patients.[4] ME/CFS may be caused by the activation of the immune system, both within and outside the brain, which induces the release of inflammatory cytokines. ME/CFS is presumed to cause abnormalities in the central and autonomic nervous systems, systemic energy metabolism, and immune system and also involve oxidative and nitrosative stress.[4,5,6] Dysfunctions in systemic energy metabolism may be related to abnormalities in the structure and function of mitochondria.[7,8,9,10]

Molecular hydrogen (H2) is a gaseous molecule that selectively scavenges reactive oxygen and nitrogen species with strong oxidizing power, namely, hydroxyl radicals (·OH) and peroxynitrite, respectively.[11,12] H2 easily crosses the blood-brain barrier and biological membranes, reaches mitochondria, and protects cells from ·OH-induced cell damage.[11,12] A recent literature review revealed that H2 attenuated acute or chronic fatigue in animals and healthy subjects.[13] We also reported that the anti-fatigue effects of H2 involved the protection of mitochondria, which may also ameliorate the pathogenesis of ME/CFS.[13] Therefore, we conducted this case study to test this hypothesis by examining the efficacy of H2 gas inhalation in four patients with ME/CFS.

Source: Hirano, Shin-ichi*; Ichikawa, Yusuke; Sato, Bunpei; Takefuji, Yoshiyasu; Satoh, Fumitake. Successful treatment of myalgic encephalomyelitis/chronic fatigue syndrome using hydrogen gas: four case reports. Medical Gas Research 14(2):p 84-86, June 2024. | DOI: 10.4103/2045-9912.385441 https://journals.lww.com/mgar/fulltext/2024/14020/successful_treatment_of_myalgic.7.aspx (Full text)