How long has homeopathy been used?

Homeopathy has been used for over 200 years. It was developed in the late 18th century by a German physician named Christian Friedrich Samuel Hahnemann. Hahnemann believed that "like cures like," and that a substance that causes symptoms in a healthy person can also cure those symptoms in a sick person. He developed a system of diluting substances to very low concentrations, which he believed made them more effective. Homeopathy is still practiced today by some people, although there is no scientific evidence to support its effectiveness.