Why you can trust
this directory.
One in three websites about "hydrogen water" blends evidence with marketing. Not here. Every study in the directory passed these four filters before getting in.
01Inclusion criteria
- Published in an indexed, peer-reviewed journal.
- DOI verifiable in Crossref.
- Human subjects (we exclude in vitro and animal studies from this directory).
- Molecular H₂ as the primary intervention (water, gas, bath, IV, or saline).
- Measurable clinical outcome (not only biochemical).
02Crossref audit
Before including a study we verify: the DOI resolves to the correct publication; the journal is real and indexed; authors and affiliation match the record; publication date is correct. If anything doesn’t check out, it doesn’t go in.
03Four evidence levels
- Level 1 — Meta-analyses and systematic reviews. The summit.
- Level 2 — Randomized controlled trials (RCTs). The standard.
- Level 3 — Observational and safety studies.
- Level 4 — Extraordinary case reports. Documented anecdote.
This hierarchy follows the convention used by GRADE and the Cochrane Collaboration.
04Nine thematic blocks
Once classified by level, we regroup studies by body system or family of conditions. So a cardiologist can look at "Cardiometabolic" only, and a dermatologist at "Autoimmune" only. See the 9 blocks.
05What we report in each article
For each study we publish: full citation, DOI, year, journal, methodological design, sample size, H₂ dose and route, duration, primary and secondary outcomes, and a narrative summary. Where there are serious limitations, we say so in the body of the article, not in a footnote.
06Conflicts of interest
We don’t take sponsorships from H₂ machine manufacturers. We don’t sell products. We have no commercial affiliates. If a researcher in the directory publishes a new study with a declared conflict of interest, we report it.
07Errors and corrections
If you find an error, tell us. If a study was retracted, we remove it from the directory or mark it as retracted. If a new meta-analysis changes the landscape, we update the corresponding block.