I've tried a few. I had great results with Valerian Root for sleepiness for about two weeks. Then the effect tapered off and finally disappeared. As if I had become dependent or adapted to it. So I stopped it and switched to Gaia Sleep tea. That worked for another 2 weeks and is now tappering off.
This year I've planted a lot of the normal cooking herbs and they're growing beautifully. I chop them up and add them to almost every thing. But I've noted no difference other than taste.
"When the search for truth is confused with political advocacy, the pursuit of knowledge is reduced to the quest for power." - Alston Chase