We have a wonderful Quarter/Paint cross mare that is VERY high strung under saddle and is an energy machine!
This mare loves to work but she doesn't know when to gear down. She acts like this whether she's being asked to "work" or enjoy a leisurely hack down the road. She has never been out of control and other than the constant jogging when riding her, has never offered to buck or bolt. She has great ground manners and is very laid back when grooming/tacking, the only time she is hyper is under saddle.
We have heard about different vitamins and oils that can be used to naturally help calm a horse like this down but we have never used any of these ourselves so would love the opinion of people who have.