Hello,
I have been reading about this intermittently. Thought of making a post and collating all information.
I invite all to add, disseminate and provide your inputs.
05-05-2023:
Since the water ionizers are exorbitantly expensive, the milion doller question is whether it makes sense to invest in one?
Hydrogen in Drinking Water Reduces Dopaminergic Neuronal Loss in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine Mouse Model of Parkinson's Disease
ncbi.nlm.nih.gov/pmc/articl...
I just decided today to start using my $189 hydrogen water maker bottle (mostly because I paid $189 for it) 
Happy for you
I thought that might come off bad. I am not wealthy. I was just trying to make the point that we spend so for things of questionable value. Desperation does that.
This is odd. I went back to look at the bottle I bought and it says it comes with a hydrogen inhaler adapter. I am sure it did not include that when I got mine in 2021. So with this bottle you can drink it or breathe it.
H2 USB Sport MAXX Hydrogen Water Generator with Glass Bottle and Inhaler Adapter (Silver) $199 amazon.com/gp/product/B07FK...
Found my box! I do have that breathing hydrogen adapter. I share the use of the bottle, so I don't see me using the adapter. Seems like a possibility of introducing germs to the bottle. I think the water is the more effective (if it is effective).
Apparently gas inhalation gave no benefit
Yes! Which makes me feel better about not noticing that feature on my unit.
👍
Electrolyzed-Reduced Water: Review I. Molecular Hydrogen Is the Exclusive Agent Responsible for the Therapeutic Effects
Molecular Hydrogen: an Emerging Therapeutic Medical Gas for Brain Disorders
Effects of hydrogen gas inhalation on L-DOPA-induced dyskinesia
Parkinson’s disease may be due to failure of melanin in the Substantia Nigra to produce molecular hydrogen from dissociation of water, to protect the brain from oxidative stress
Renoprotective and neuroprotective effects of enteric hydrogen generation from Si-based agent
Randomized double-blind placebo-controlled trial of hydrogen inhalation for Parkinson’s disease: a pilot study
Effects of concomitant use of hydrogen water and photobiomodulation on Parkinson disease
A randomized double-blind multi-center trial of hydrogen water for Parkinson’s disease: protocol and baseline characteristics
is there a preferred way of producing hydrogen water and what is the recommended amount to drink on a daily basis
Multiple system atrophy and hydrogen
Gabapentin and Parkinson's 
Parkinson's and me
