I am still yet to see any decent studies into whether or not L-Theanine actually does anything at all. Studies never seem to find anything statistically significant, yet so many people swear by it. I'm inclined to say it is placebo.
This email in particular is extremely prevalent. Always with spaces breaking up the text in different spots as a rudimentary filter bypass measure.
It has been running in this form with only the most minor of changes to the text for years. There have been times when emails I monitor have gotten 10+ of this message in a single day.
Good recent writing on the topic: https://dynomight.net/theanine-2/
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