Molecular hydrogen is being studied intensely in Asia by MD's and PhD's with over 600 studies published, it helps with over 166 human identified conditions. They have done in vitro, in vivo and human studies. It has been shown to be safe for everyone, as the body makes it naturally every day in the intestines. The clinical studies are mostly reported from Japan, Korea and China, the three countries that are actively funding molecular hydrogen research.
Hydrogen gas is reported to have no cytotoxicity even at high concentrations. The safety of H2 for humans is demonstrated by its application in Hydreliox, an exotic breathing gas with a mixture of 49% H2, 50% helium and 1% O2, which is used to prevent decompression sickness and nitrogen narcosis during very deep technical diving. ( 1 ) With Hydreliox in their tanks, scuba divers can safely pursue diving depths of up to four hundred feet.
Hydrogen water has lots of not understood properties. Ex:. The absolute tiniest concentration dissolved in water has still statistical significant effects. Notably, H2 concentrations as low as 0.08 ppm exhibited nearly the same effects as saturated Hydrogen water with (1.5 ppm). Therefore, the amount of administered H2 seems to be independent of the magnitude of effects in many cases.
Nevertheless, promising applications for H2 treatment are expected to emerge for many human diseases, and personalized treatments for patients are a therapeutic goal. Thus, appropriately designed, large-scale, prospective clinical studies are warranted to optimize H2 dose, timing, and delivery methods.
The positive effects of H2 have been observed in practically all organs covering 31 disease categories that can be subdivided into 166 disease models, human diseases, treatment-associated pathologies, and pathophysiological conditions of plants with a predominance of oxidative stress-mediated diseases and inflammatory diseases.
These publications are very instructive because they summarize all current and past studies on Hydrogen.
2016: Dr. Gart L. Nicholson reports on 338 publications studying the benefits of molecular hydrogen at scirp.org:
Click any of the links above and search in the opening document for the medical term you are interested in.
Tip: you will find bracketed numbers like this:  all over in the document. Clicking them will show the url of the original publication at the bottom of the document.
A collection of really interesting publications. The scope of the listed research covers nearly every disease known.
Listed below, there are a lot of animal studies, but considering the non-toxicity and benign nature of Hydrogen, it is possible to experiment in any direction.
Bipolar - Schizophrenia
Cerebral Ischemia Reperfusion
Excessive production of free radicals
Gastric injury, ulcers, alcohol damage
Search and review the nih.gov: HTML
Search and review biomedcentral.com: HTML
A couple of general articles about Hydrogen.
The reference links to hydrogen information
I guess everyone gets the idea by now that this is the real McCoy.