Homeopathy is built on a powerful idea: "like cures like." A substance that can cause symptoms in a healthy person may, when given in a micro-dose, trigger the body to correct those same symptoms in someone unwell.
This principle, the Law of Similars, has been around since the 1700s, discovered by German physician Samuel Hahnemann. He believed medicine should support the entire person, emotionally, mentally and physically, not just silence one symptom.