I do give one of my horses scoop of herb calmer (chammomile and vervain) in her feed (it's just half of the recommended dose). Actually yes, I did notice the difference, not just to ride, but her behavior in field - she's more relaxed and not as alert. But from what I know calmers work differently on different horses.
"Life isn't about waiting for the storm to pass: it's about learning to dance in the rain..."
"When we are no longer able to change a situation - we are challenged to change ourselves."
"How people treat you is their karma; how you react is yours."