Hi there matron yes I know people that have used it and I use theanine at 500mg (this is the high end dosing) and finds it really relaxes me and chills me out and works very well It's also good for when you've had too much caffeine as it takes the edge off it. If I were you I'd start at the low end 50-100mg and assess tolerance and work your way up from there till you find your sweet spot. Side affects wise I've found none at this dose, obviously if you're taking medication you'd need to check whether there are any interactions. Report back here if/when you decide to take it and tell us what's your take on this.