• Mistletoe is a plant that grows on several types of trees and has been used since ancient times to treat many ailments (see Question 1 ¹ and Question 2 ²).



• Mistletoe extract has been shown to kill cancer cells in the laboratory and to boost the immune system (see Question 3 ³).



• Animal studies have suggested that mistletoe may be useful in decreasing the side effects of standard anticancer therapy (see Question 5 ⁴).



• Many human studies using mistletoe to treat cancer have been done in Europe with unclear results, and a few clinical trials in the United States and abroad are in progress (see Question 6 ⁵).



• Very few bad side effects have been reported from the use of mistletoe extract, though mistletoe plants and berries are poisonous to humans (see Question 7 ⁶).



• The U.S. Food and Drug Administration (FDA) has not approved mistletoe as a treatment for cancer or any other medical condition (see Question 8 ⁷).



• The FDA does not allow injectable mistletoe to be imported or used except for clinical research (see Question 8 ⁷)

Glossary Terms

A term for diseases in which abnormal cells divide without control. Cancer cells can invade nearby tissues and can spread to other parts of the body through the blood and lymph systems. There are several main types of cancer. Carcinoma is cancer that begins in the skin or in tissues that line or cover internal organs. Sarcoma is cancer that begins in bone, cartilage, fat, muscle, blood vessels, or other connective or supportive tissue. Leukemia is cancer that starts in blood-forming tissue such as the bone marrow, and causes large numbers of abnormal blood cells to be produced and enter the blood. Lymphoma and multiple myeloma are cancers that begin in the cells of the immune system. Central nervous system cancers are cancers that begin in the tissues of the brain and spinal cord.

The individual unit that makes up the tissues of the body. All living things are made up of one or more cells.

A type of research study that tests how well new medical approaches work in people. These studies test new methods of screening, prevention, diagnosis, or treatment of a disease. Also called a clinical study.

In medicine, a preparation of a substance obtained from plants, animals, or bacteria and used as a drug or in drugs.

FDA. An agency in the U.S. federal government whose mission is to protect public health by making sure that food, cosmetics, and nutritional supplements are safe to use and truthfully labeled. The Food and Drug Administration also makes sure that drugs, medical devices, and equipment are safe and effective, and that blood for transfusions and transplant tissue are safe. Also called FDA.

The complex group of organs and cells that defends the body against infections and other diseases.

Use of a syringe and needle to push fluids or drugs into the body; often called a "shot."

A semiparasitic plant that grows on some types of trees. Mistletoe extracts are being studied as treatments for cancer.

A problem that occurs when treatment affects healthy tissues or organs. Some common side effects of cancer treatment are fatigue, pain, nausea, vomiting, decreased blood cell counts, hair loss, and mouth sores.

In medicine, treatment that experts agree is appropriate, accepted, and widely used. Health care providers are obligated to provide patients with standard therapy. Also called standard of care or best practice.

Treatment.