I've been taking theanine for at least 2 years now ... I used 100 mg 3 times a day when I first started taking this and it worked like a charm ... Later used it at bedtime only to control nocturnal myoclonus (jerking when entering REM) it worked then too ...
FWIW though ... I found that I don't need this if I avoid all gluten though ... I react to certain other foods (mostly glutamates) in different ways but gluten really makes me anxious ...
The reason I needed Theanine 3 times a day in the beginning was because I was being cross contaminated by a houseguest who was eating gluten every day ... Once she left so did my need for Theanine ...