These are homeopathic remedies, they are so dilute that there is nothing left of the original substance, merely a vibration/essence of it. It is said to work on a like cures like basis. If a large amount of the undiluted substance was taken it would cause xxx symptoms, the homeopathic version is supposed to cure similar symptoms. So, in the case of Ipeac, which can cause sickness, a homeopathic remedy of it is said to help with sickness, or feelings of sickness, and anything else a large dose of Ipeac would cause.