Posted 19 November 2013 - 11:03 AM
Like you said, gaba does not cross the bbb, so if you want to affect your brain it's out.
Phenibut as far as I know is, depending on dose, a strong gaba agonist meaning it will fuck with your gaba system (reducing receptors, decreasing the effect of any substance including self produced gaba in the brain).
Picamilon should have the same negative effects phenibut has, since it delivers gaba through the bbb, again resulting the receptors to decrease because the brain did not want that gaba there.
theanin, as far as I know does not do this. it does increase gaba amongst other things, but it makes the brain increase gaba production, which might be the important difference resulting in no receptor reduction or less reduction depending on dosage. It's not clear if this is the case I guess, but my experience with it clearly shows that I have no problems to stop taking it, meaning my gaba system is not downregulating.
In any case theanine is the least problem causing drug if you want to get effects of increased gaba in your brain.