[brandonasuncion]

I've tried different L-Theanine supplements, and there's definitely a difference in quality across companies... which could help explain the variance in experiences.

Unfortunately, there isn't much regulation for supplements in general. Some companies do 3rd party purity testing, though it's not always the case.

[AlecSchueler]

> I've tried different L-Theanine supplements, and there's definitely a difference in quality across companies...

This could also be explained by placebo effects.