# Mistletoe (Viscum album)

**Viscum*; all-heal*

**Known today as.** *Viscum album*, especially when found on oak.

Kind: Plant  
Poisoning: Gastrointestinal irritants (https://thethinkingpress.org/materia-medica/poisons/gastrointestinal)  
Toxic: yes

> **Caution.** The berries are poisonous.

## What was it used for?

Against the falling sickness and apoplexy; worn as an amulet.

## What does modern science say?

Mistletoe extracts are used alongside cancer treatment in parts of Europe, with weak evidence; the berries are poisonous.

## Pharmacognosy and toxicology

- **viscotoxin**: 
- **mistletoe lectin I**: 

**Mechanism.** The lectins inhibit protein synthesis and stir immune cells; the viscotoxins injure cell membranes.

**Dose.** The berries have poisoned children; injected extracts are a different matter.

**Standing.** Injected mistletoe extracts are widely used in German cancer care; trials show no survival benefit.

## What lore surrounds it?

The Christmas kissing custom is far younger than the myth of Balder or the druids’ rite, and unrelated to either. The earliest known reference is an English poem of 1784, and by the early nineteenth century Washington Irving could describe the custom fully formed: each berry plucked from the sprig stood for a kiss allowed, and a refusal was held to bring bad luck in marriage.

## What did the older authorities say?

**Pliny.** The druids held nothing more sacred than mistletoe on an oak, cut with a golden sickle on the sixth day of the moon, with the sacrifice of two white bulls.

**The Prose Edda.** The god Balder, whom nothing could harm, is slain by a dart of mistletoe.

**John Colbatch.** Recommended it against epilepsy in a treatise of 1720.

## Sources

- Pliny, *Natural History* XVI.
- Colbatch, J. (1720). *A Dissertation concerning Mistletoe*.
- Smithsonian Magazine, “How Mistletoe Became a Christmas Kissing Tradition.”
- Freuding, M., et al. (2019). “Mistletoe in oncological treatment: a systematic review.” *Journal of Cancer Research and Clinical Oncology* 145.

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*Mistletoe.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-09-25. The Thinking Press. https://thethinkingpress.org/materia-medica/mistletoe

Historical description, not medical advice.