[sp332]

L-theanine is popular, I take it in a pill but Soylent added it to their coffee product. (Edit: NOS energy drinks also include L-theanine.) Others I've seen around include Bacopa monnieri, choline, Rhodiola rosea. More examples here https://nootrobox.com/full-stack

[blacksmith_tb]

Some of us consume our l-theanine in tea, which also contains caffeine (and some other friendly phytochemicals).

[germinalphrase]

Do you favor a particular kind of tea?