Homeopathy is a system of alternative medicine that was developed in the late 18th century by Samuel Hahnemann. It is based on the idea that a substance that causes the symptoms of a disease in a healthy person can be used to treat that disease in a sick person. Homeopathic remedies are usually made from natural substances, such as plants or minerals, and are prepared by diluting the substance in water or alcohol. The effectiveness of homeopathic remedies is not supported by scientific evidence,