Homeopathy is an alternative medical practice in which extremely dilute amounts of certain natural substances are used to treat various ailments.

Homeopathy was developed in the late 18th century by Samuel Hahnemann, a respected doctor in Germany. Hahnemann believed that “like cures like” and that minute concentrations of a particular toxin could cure the very same symptoms it would cause in larger doses. Think poison ivy to treat rashes.

This notion of “like cures like” was similar to the emerging science of inoculation and vaccination. And Hahnemann’s treatments in their dilute forms were far safer than most medical practices during his time, such as bloodletting.