Long post, sorry. Glycine: what actually has human evidence behind it, and what is extrapolation from animals?
Most of the popular protocols are borrowed from clinical populations and applied to healthy people without comment.
If you need three other compounds to notice the first one, you have not tested the first one.
There is a serious question about whether the studied form matches what is sold, and nobody in a thread can answer it.
The comparison group matters more than the compound when the outcome is something as fuzzy as focus.
Happy to be corrected on any of the above.
How long before you can reasonably say something is or is not doing anything?
Most of what is called evidence here is one person, one vial, one month.
Same here.
How long have you been on glycine?
Reconstitution arithmetic is only half the problem. The other half is what was in the vial.