Yes, I take l-theanine every morning because I tend to wake up with anxiety. In 15 minutes...Gone!
It is BS. Thiamine helps with carbohydrate metabolism and prevents malnutrition symptoms. If you are active, 1.5 to 2 mg is optimal.
For your consideration.
My understanding is that morning anxiety is caused by higher cortisol levels and that even something as simple as moving around and becoming active can help reduce those levels.
How To Break The Cycle Of Morning Anxiety
https://www.re-origin.com/articles/how-to-break-the-cycle-of-morning-anxiety