Hydrogen Water for Mountain Sickness: A Negative Trial

Quick answer

Not every study is a win, and we publish those too. In a 2025 blinded, placebo-controlled trial (Zhang et al., High Altitude Medicine & Biology), hydrogen-rich water failed to reduce oxidative stress in patients with chronic mountain sickness over eight weeks. Worse, it appeared to push an oxidative-damage marker the wrong way — more so in people with a higher BMI. This is a genuine cautionary result.

What the study did

Sixty adults with untreated chronic mountain sickness (CMS) at a hospital in Nagqu, Tibet, were randomly assigned to drink 990 mL a day of either hydrogen-rich water or a placebo for eight weeks. Everyone — participants, clinicians, and investigators — was blinded to who got what. The main goal was the change in a panel of oxidative-stress markers, including catalase, glutathione, malondialdehyde (MDA), superoxide dismutase, 8-OHdG, and total antioxidant capacity (T-AOC). Side effects were tracked too.

What it found

• Compared with placebo, hydrogen water produced a larger rise in MDA — a marker of oxidative damage, so up is bad (+2.11; 95% CI 1.13–3.09; p < 0.001).
• It also raised total antioxidant capacity (+2.86; p = 0.043) — a mixed, contradictory picture.
• In participants with a BMI of 24 or higher, the MDA increase was more pronounced (p = 0.02 for interaction).
• Side effects occurred in 50% of the hydrogen group vs 37% of placebo, most often dizziness.

What this means for you

The authors' own conclusion is the headline: hydrogen water showed both pro-oxidative and antioxidative effects, did not reduce oxidative-stress damage in chronic mountain sickness, and may increase oxidative risk in people with a higher BMI.

Context matters — this was a specific, high-altitude patient group, not healthy people at sea level, so it doesn't erase the positive findings in other conditions. But it's a real reminder that hydrogen water isn't automatically beneficial everywhere, and that "antioxidant" doesn't mean "harmless in every setting." If you have a serious altitude-related condition, this is a talk-to-your-doctor situation, not a self-treat one.