# Mistletoe extracts (Iscador, Helixor)

Source: https://onco.cc/technologies/mistletoe-extracts/  
OnCo record `mistletoe-extracts` (Technology). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

Injectable mistletoe extracts are the most prescribed complementary cancer treatment in German-speaking Europe. Decades of studies have not shown that they lengthen life; some suggest better quality of life during chemotherapy, but the trials are weak and the largest well-run ones were negative.

## Summary

Fermented and unfermented extracts of Viscum album contain lectins and viscotoxins that are cytotoxic and immunostimulatory in vitro. A 2008 Cochrane review of 21 randomised trials found the evidence for survival benefit weak and inconsistent, with some trials of low methodological quality reporting better quality of life and reduced chemotherapy side effects; higher-quality trials were largely negative, and a well-designed trial in melanoma reported a possible increase in metastases. A 2013 phase 3 in advanced pancreatic cancer in Serbia reported longer survival with mistletoe versus best supportive care alone, but it was unblinded, in patients not receiving chemotherapy, and has not been replicated; a US phase 1 of intravenous mistletoe (Johns Hopkins, 2023) established a dose without efficacy data. The NCI PDQ summary concludes that available evidence does not support mistletoe as a cancer treatment. Injection-site reactions and fever are common; serious harm is rare.

## Fields

- Kind: Technology
- Status: phase-2
- Last checked: 2026-09-10
- Tags: complementary; supportive-care; evidence:insufficient
- Principle: Mistletoe lectins induce apoptosis and cytokine release in vitro and are proposed to stimulate anti-tumour immunity; clinically meaningful immune effects have not been demonstrated.
- Strengths: Long safety record; Some trials report better quality of life during chemotherapy
- Limitations: No reliable survival benefit; Best-quality trials negative; Possible harm signal in melanoma

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Viscum_album
- Cochrane: mistletoe therapy in oncology (2008): https://doi.org/10.1002/14651858.CD003297.pub2
- NCI PDQ: Mistletoe extracts: https://www.cancer.gov/about-cancer/treatment/cam/hp/mistletoe-pdq
- MSK About Herbs: Mistletoe: https://www.mskcc.org/cancer-care/integrative-medicine/herbs/mistletoe

## Connected records

- cancers: [HR-positive / HER2-negative breast cancer](https://onco.cc/cancers/breast-hr-positive/), [Melanoma](https://onco.cc/cancers/melanoma/), [Pancreatic ductal adenocarcinoma](https://onco.cc/cancers/pancreatic/)
- fronts: [Supportive Care & Survivorship](https://onco.cc/fronts/supportive-care/)
- technologies: [Evidence-based integrative oncology](https://onco.cc/technologies/integrative-oncology/)
- bottlenecks: [Failures are hidden](https://onco.cc/bottlenecks/b-negative-results/), [Misinformation and unproven therapies](https://onco.cc/bottlenecks/b-misinformation/)
- key papers: [Mistletoe therapy in oncology](https://onco.cc/key-papers/paper-horneber-cochrane-database-syst-rev/)

---
JSON: https://onco.cc/api/v1/entities/mistletoe-extracts.json