Mistletoe (latin: Viscum album) is a parasitic plant that grows on trees. It has a long history of use as a medicinal plant in Europe, used traditionally for heart disease, high blood pressure, epilepsy, delirium, and neuralgia, among other ailments. More recently, it has been used in Europe for treating cancer. There has been quite a bit of research regarding the use of mistletoe in cancer treatment. Tumor necrosis factor alpha and NK cell activity, both important indicators of the immune system’s ability to fight cancer, have been shown to increase with mistletoe treatments. Iscador, a popular formulation of mistletoe extract, has been the subject of many studies, where it has demonstrated improved disease-free survival times and mean survival times, improved quality of life, and decreased side effects from chemotherapy, in patients of various forms of cancer.
Mistletoe is usually given by subcutaneous injection, though sometimes it is given orally, or injected directly into the tumor. When used correctly by a trained physician, it is quite safe, with common side-effects being limited to redness at the site of injection and a low-grade fever.