# Birch polypore (Fomitopsis betulina)

**Fomitopsis betulina*; razor-strop fungus*

**Known today as.** A white bracket of dead birch.

Kind: Fungus

## What was it used for?

Used to strop razors, and as a dressing for wounds.

## What does modern science say?

Its compounds are antibacterial and act against some parasites in the laboratory.

## Pharmacognosy and toxicology

- **polyporenic acids**: lanostane triterpenes
- **piptamine**: an antibiotic
- **betulinic acid**: a triterpene
- **beta-glucans**: 

**Mechanism.** Its triterpenes suppressed inflammation in mice, and piptamine acts against bacteria and yeasts in the laboratory; fresh pieces were laid on wounds as antiseptic dressings in folk medicine. Ötzi carried two pieces, perhaps for the whipworm he had; its agaric acid is poisonous to that worm.

**Dose.** Considered inedible, except perhaps when young.

**Standing.** A folk remedy, especially in Russia, the Baltic countries, Hungary and Romania; now studied for its antibacterial, anticancer and other activities.

## What lore surrounds it?

Ötzi carried two pieces of it with leather strings through them. Because he had whipworm, some have proposed he carried it as a medicine.

## Sources

- Wikipedia, “Fomitopsis betulina,” en.wikipedia.org (read 2 October 2026).
- Wikipedia, “ötzi,” en.wikipedia.org (read 2 October 2026).
- Pleszczyńska, M., et al. (2017). “*Fomitopsis betulina* (formerly *Piptoporus betulinus*): the Iceman’s polypore fungus with modern biotechnological potential.” *World Journal of Microbiology and Biotechnology* 33.

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*Birch polypore.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/birch-polypore

Historical description, not medical advice.