The medicinal part is the root. The components in Ginger that are responsible for the antiemtic effect are thought to be the gingerols and shogaols. The mechanism of action is not due to a nystagmus response or vestibular stimulation.
Ginger root is one such herb.
Megabust contains Ginger to take care of any stomach upset that the other items could possibly cause and because of its specific action of increasing blood flow to the pelvic area.