Marshmallow Root is a supplement for anger and is meant to calm and soothe you. Further studies are needed to confirm these speculations. L-tyrosine has the potential to make you more amiable by increasing dopamine, norepinephrine, and epinephrine. I've worked with people where this did nothing for them, and I've worked with people whose lives were changed dramatically by the increase in energy and positivity.
Saffron calms you down and improves your mood. The maximum dosage is 400mg, but that would be hard to achieve with most of what's sold.