A yoni egg is a smooth, egg-shaped stone that is inserted into the vagina for Kegel training. They are also known as jade eggs, although they can be made of various crystals such as quartz or obsidian. The word "yoni" is Sanskrit for "womb," although modern use usually refers to yoni as the vulva or vagina. The weight of the egg is meant to act as a Kegel ball, and the material its made of is meant to promote crystal energy healing. However, there is no scientific evidence that yoni eggs work in any of these capacities. In fact, using yoni eggs can cause bacterial infections and intense pain. Most medical professionals agree that yoni eggs dont have any medical benefits and, in fact, using them can actually harm the vagina. Yoni eggs are not shown to have any scientific medical use. Therefore, it is not recommended to use yoni eggs as they can be harmful to vaginal health.