I've been taking L-theanine with my coffee for a few years now. It has a noticeable positive impact on my ability to focus and think clearly. I also feel a lot

I've been taking L-theanine with my coffee for a few years now. It has a noticeable positive impact on my ability to focus and think clearly. I also feel a lot more comfortable taking it than other nootropics, because a) it's just a naturally-occurring amino acid, b) I'm not aware of any negative side effects reported from using it.