Extracts from this woody plant are injected or infused for cancer treatment, often reducing side effects and improving quality of life, and perhaps improving survival.

Safety and precautions

We at CancerChoices strongly advise anyone thinking about using mistletoe to consult a physician knowledgeable and experienced in its use to prescribe it and monitor your response.

Common side effects are typically mild but can depend on the dose.1Mistletoe (Viscum album). Centre for Health Innovation. February 2024. Viewed May 28, 2024;; Horneber MA, Bueschel G, Huber R, Linde K, Rostock M. Mistletoe therapy in oncology. Cochrane Database of Systematic Reviews. 2008 Apr 16;(2):CD003297.

Several cautions, contraindications, adverse events, and herb-drug interactions are described in the Centre for Health Innovation monograph, Mistletoe (Viscum album)

Subcutaneous injections: injection site reactions (redness, swelling, itching), fatigue, flu-like symptoms, mild fever, diarrhea, and headache. Severe local reactions at the injection site occur in fewer than 1% of people.

Intravenous infusions: mild fever, itching, weakness, fatigue, re-inflammation of prior injection sites.

Serious reactions are rare but include these:

  • Severe, potentially life-threatening allergic or pseudo-allergic reactions (anaphylaxis)
    • Swelling of throat, skin and mucous membranes (angioedema)
    • Low blood pressure (hypotension) 
    • Loss of consciousness
  • Skin infection (cellulitis) at the injection site

Side effects or adverse events

Incidence and severity of side effects from subcutaneous mistletoe use are reported in a 2014 study. The most common:2Steele ML, Axtner J et al. Adverse drug reactions and expected effects to therapy with subcutaneous mistletoe extracts (Viscum album L.) in cancer patients. Evidence-Based Complementary and Alternative Medicine. 2014;2014:724258.

  • Fever
  • Local reaction
  • Hives (urticaria)
  • Injection site redness of the skin (erythema)
  • Chills

A few people with high-risk malignant melanoma experienced adverse drug reactions, requiring therapy termination in fewer than 2% of patients receiving mistletoe.3Augustin M, Bock PR, Hanisch J, Karasmann M, Schneider B. Safety and efficacy of the long-term adjuvant treatment of primary intermediate- to high-risk malignant melanoma (UICC/AJCC stage II and III) with a standardized fermented European mistletoe (Viscum album L.) extract. Results from a multicenter, comparative, epidemiological cohort study in Germany and Switzerland. Arzneimittelforschung. 2005;55(1):38-49.

A few cases of anaphylactic shock have been reported with use.4Hutt N, Kopferschmitt-Kubler M et al. Anaphylactic reactions after therapeutic injection of mistletoe (Viscum album L.). Allergologia et Immunopathologia (Madr). 2001 Sep-Oct;29(5):201-3. Higher doses of mistletoe (2000 mg pine-mistletoe extract or 4800 or greater ng/kg of mistletoe lectins), particularly given intravenously or intratumorally, increase risk for allergic or pseudo-allergic reactions, fever, and other side effects.5Huber R, Schlodder D, Effertz C, Rieger S, Tröger W. Safety of intravenously applied mistletoe extract—results from a phase I dose escalation study in patients with advanced cancer. BMC Complementary and Alternative Medicine. 2017 Sep 18;17(1):465; Kienle GS, Grugel R, Kiene H. Safety of higher dosages of Viscum album L. in animals and humans–systematic review of immune changes and safety parameters. BMC Complementary and Alternative Medicine. 2011 Aug 28;11:72; Hutt N, Kopferschmitt-Kubler M et al. Anaphylactic reactions after therapeutic injection of mistletoe (Viscum album L.). Allergologia et Immunopathologia (Madrid). 2001 Sep-Oct;29(5):201-3.

Do not use (contraindications)

According to Neil McKinney, ND, mistletoe should not be used with a fever greater than 100.4°F (38°C), nor with abdominal fluid (ascites) or with brain tumors or other tumors in tight compartments where an immune response can cause initial inflammatory swelling (edema) and subsequent compression of vital structures.6McKinney N. Naturopathic Oncology, 3rd Edition. Victoria, BC, Canada: Liaison Press. 2016.

Dr. McKinney says mistletoe may activate a hidden focus of infection, such as dental abscess. He also cautions that increased cytokine release may aggravate wasting (cachexia). He considers mistletoe to be contraindicated in pregnancy, breastfeeding, tuberculosis, biliary stenosis, liver failure, heart failure, kidney failure, hyperthyroidism, and with interferon or interleukin therapies.7McKinney N. Naturopathic Oncology, Fourth Edition. Victoria, BC, Canada: Liaison Press. 2020.

Keep reading about mistletoe


Nancy Hepp, MS

Lead Researcher
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Ms. Hepp is a researcher and communicator who has been writing and editing educational content on varied health topics for more than 20 years. She serves as lead researcher and writer for CancerChoices and also served as the first program manager. Her graduate work in research and cognitive psychology, her master’s degree in instructional design, and her certificate in web design have all guided her in writing and presenting information for a wide variety of audiences and uses. Nancy’s service as faculty development coordinator in the Department of Family Medicine at Wright State University also provided experience in medical research, plus insights into medical education and medical care from the professional’s perspective.

Nancy Hepp, MS Lead Researcher


Laura Pole, MSN, RN, OCNS

Senior Clinical Consultant
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Laura Pole is senior clinical consultant for CancerChoices. Laura is an oncology clinical nurse specialist who has been providing integrative oncology clinical care, navigation, consultation, and education services for over 40 years. She is the co-creator and co-coordinator of the Integrative Oncology Navigation Training at Smith Center for Healing and the Arts in Washington, DC. Laura also manages the “Media Watch Cancer News That You Can Use” listserv for Smith Center/Commonweal. In her role as a palliative care educator and consultant, Laura has served as statewide Respecting Choices Faculty for the Virginia POST (Physician Orders for Scope of Treatment) Collaborative as well as provided statewide professional education on palliative and end-of-life care for the Virginia Association for Hospices and Palliative Care.

For CancerChoices, Laura curates content and research, networks with clinical and organizational partners, brings awareness and education of integrative oncology at professional and patient conferences and programs, and translates research into information relevant to the patient experience as well as clinical practice.

Laura sees her work with CancerChoices as a perfect alignment of all her passions, knowledge and skills in integrative oncology care. She is honored to serve you.

Laura Pole, MSN, RN, OCNS Senior Clinical Consultant

Gunver Sophia Kienle, MD

Physician, medical researcher, and CancerChoices advisor
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Dr. Kienle studied medicine in Witten-Herdecke and Göttingen, Germany, and received methodological training at Harvard University in the USA. Her research interests and activities include clinical trials on anthroposophic medicine, mistletoe therapy, eurythmy therapy, placebo effects, clinical research methodology, clinical judgement, single-case study designs, case reporting, cognition-based medicine, systematic reviews on pre-clinical and clinical studies on mistletoe therapy, and reviews on tumor biology, tumor immunology, bacterial vaccine therapy, and system approaches in medicine. Dr Kienle has conducted a health technology assessment report on anthroposophic medicine.

Gunver Sophia Kienle, MD Physician, medical researcher, and CancerChoices advisor

Last update: May 28, 2024

Last full literature review: October 2021

CancerChoices provides information about integrative in cancer care, a patient-centered approach combining the best of conventional care, self care and evidence-informed complementary care in an integrated plan cancer care. We review complementaryin cancer care, complementary care involves the use of therapies intended to enhance or add to standard conventional treatments; examples include supplements, mind-body approaches such as yoga or psychosocial therapy, and acupuncture therapies and self-care lifestyle actions and behaviors that may impact cancer outcomes; examples include eating health-promoting foods, limiting alcohol, increasing physical activity, and managing stress practices to help patients and professionals explore and integrate the best combination of conventionalthe cancer care offered by conventionally trained physicians and most hospitals; examples are chemotherapy, surgery, and radiotherapy and complementary therapies and practices for each person.

Our staff have no financial conflicts of interest to declare. We receive no funds from any manufacturers or retailers gaining financial profit by promoting or discouraging therapies mentioned on this site.

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