Mistletoe and Immunotherapy: How They Work Together to Improve Cancer Survival
Introduction
Cancer immunotherapy has changed the way doctors treat cancer, helping the body’s immune system recognize and attack tumours. However, not all patients respond, and side effects can be difficult to manage. This has led researchers to explore natural therapies that can strengthen the immune system and make treatments work better. One such option is mistletoe therapy, an extract from the Viscum album plant that has been used in complementary cancer care for over a century. Studies suggest that when used together with immunotherapy, mistletoe may help patients live longer, feel better, and tolerate treatment more easily. This article explains how mistletoe supports the immune system, what research has shown about its combination with immunotherapy, and what this could mean for patients in the future.
What Is Mistletoe Therapy and How Does It Work?
Mistletoe therapy uses extracts from the European mistletoe plant. These extracts are given as small injections under the skin, usually several times a week, or they can be used intravenously. They contain natural compounds, called lectins, viscotoxins, and polysaccharides, which are thought to activate immune cells like T-cells and natural killer (NK) cells that attack cancer cells. They help balance the immune response, making it stronger but less likely to cause harmful inflammation. They also trigger cancer cell death (apoptosis) in lab studies and reduce side effects from chemotherapy or immunotherapy, such as fatigue, nausea, or loss of appetite.
Most research indicates that mistletoe acts as an immune-supportive therapy, potentially helping the body respond more effectively to cancer treatment.
Immunotherapy and Why Mistletoe May Help
Immunotherapy works by “unlocking” the immune system so it can better recognize and destroy cancer cells. The most common drugs used are called checkpoint inhibitors, which target proteins like PD-1, PD-L1, or CTLA-4. These treatments can be very effective, but not everyone benefits because the tumour environment can “block” immune responses. Side effects can sometimes make it hard to continue treatment.
Mistletoe may help with these challenges by stimulating immune activity, encouraging immune cells to move into the tumour area and stay active, reducing inflammation and stress on the immune system, and improving energy and well-being, helping patients continue treatment. In this way, mistletoe and immunotherapy may work together — immunotherapy activates the immune system’s attack, while mistletoe supports and strengthens it.
Evidence from Studies
Research now looks at survival when mistletoe is used with immunotherapy. There have been several studies of patients with advanced lung cancer, and those who received mistletoe alongside immune checkpoint inhibitors had significantly longer survival times than those who had immunotherapy alone. In several smaller studies of other cancers, mistletoe appeared to enhance treatment response and reduce hospital stays when used alongside immunotherapy. Patients also reported fewer side effects and a higher sense of well-being.
Safety
Mistletoe therapy is generally well tolerated. The most common effects are mild, such as a small red bump at the injection site, mild fever, or flu-like symptoms, which often mean the immune system is responding. Serious allergic reactions are rare. Because mistletoe affects the immune system, it should only be used under medical supervision, especially when combined with immunotherapy. Doctors trained in integrative oncology can guide safe use.
Conclusion
Mistletoe therapy offers a gentle, natural way to support the immune system and improve tolerance to cancer treatment. When used alongside immunotherapy, it may help patients live longer, experience fewer side effects, and enjoy a better quality of life. Although more studies are needed to confirm these effects, current research points to mistletoe as a promising addition to cancer care, one that bridges modern medicine and nature’s healing potential.
