[silentbicycle]

L-Theanine is a surprisingly under-appreciated nootropic. If you buy it as a bulk powder, it's quite cheap.

Good Japanese green tea (senchas, matcha, etc.) seem to be particularly high in theanine. It contributes quite a bit of flavor to the tea.

[gwern]

I'd agree with theanine being under-appreciated. I used to drink a ton of tea - no problems, nice stimulant. So when I decided to mix & cap all my supplements and drop the whole tea thing (more work than a pill and not especially portable), I simply bought a few hundred grams of caffeine.

What could go wrong? Caffeine was what I was getting from the tea, right? Turns out caffeine alone makes me somewhat twitchy & anxious and is distinctly inferior to tea (caffeine+theanine). If I could cap them again, I'd definitely make sure to add in theanine.