We are a growing group of persons trying out hydrogen applications because of the confirmed non-toxicity of hydrogen at all concentrations.
The general reasoning is that we don't need to wait for more complementing human studies, Hydrogen is reportedly harmless, one can't overdose and it is a health promoting element right from the start of the application.
The promise of Hydrogen consumption is as great as calming the hands of Parkinson's disease, delaying Alzheimer, normalizing cardiovascular problems, reduce the frequency of heart-attacks, remove kidney stones, a much faster healing of chronic wounds and burn wounds, removing local pain and who knows what else will be discovered.
I have observed incredible effects: 3 days drinking hydrogen water lowered high blood pressure to normal. Kidney stones disappeared, arthritis pain removed and mobility restored after 20 min gassing the hand. Burn wounds heal fast and without pain.