To mellow out, you can drink Drank, the "anti-energy drink" that "slows your roll" by inducing sleepiness with melatonin, valerian root, and rose hips.
Or you can drink green tea, whose theanine mellows without inducing sleepiness.
Addendum: And at least Drank isn't dangerous like the über-caffeinated energy drinks can be.
The "slow your roll" philosophy is a good one indeed. But it can be attained more naturally.