Due to the extremely diluted nature of homeopathic remedies, there is no risk of negative side effects, although some herbs, such as Arnica, can have serious side effects if overdosed. On the other hand, homeopathic herbs may cause nausea, vomiting, nosebleeds, and diarrhea if they are too much. Still, since they are diluted in homeopathy, side effects are removed since the herb is extremely diluted, reducing the risk of side effects. Side effects of homeopathic medicines vary from person to person.