# Caterpillar fungus (Ophiocordyceps sinensis)

**Ophiocordyceps sinensis*; Tibetan *yartsa gunbu*, “summer grass, winter worm”*

**Known today as.** A fungus that fills and kills the buried larvae of ghost moths on the Tibetan plateau, sending up a slender stalk.

Kind: Fungus  
Qualities: Hot and moist in the first degree.

## What was it used for?

A tonic for strength and vitality in Tibetan and Chinese medicine.

## What does modern science say?

Studies in animals show some effects on energy and immunity; human evidence is weak. Most “cordyceps” sold now is the cultivated *Cordyceps militaris*.

## Pharmacognosy and toxicology

- **cordycepin**: 

## What lore surrounds it?

First described in Tibetan medical writing of the fifteenth century. Its fame soared when Chinese runners broke world records in 1993 and their coach credited it; at times it sells for more than its weight in gold.

## What did the older authorities say?

**Dioscorides.** This entity is entirely omitted by the ancient master, as it is native only to the high, snow-bound plateaus of the Far East and was completely unknown to the Greek and Roman worlds during antiquity.

**Galen.** Not recorded in the classical text. If parsed by his method, its sweet taste indicates a moderate composition, while its ability to restore vitality and moisten the respiratory organs shows it to be Hot and Moist in the first degree, working to gently renew the body's innate heat and radical moisture.

## Sources

- Winkler, D. (2008). Yartsa gunbu and the fungal commodification of Tibet’s rural economy. *Economic Botany* 62: 291–305.
- Tuli, H. S., et al. (2013). “Cordycepin: a bioactive metabolite with therapeutic potential.” *Life Sciences* 93.

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

Historical description, not medical advice.