# White willow (Salix alba)

**Salix**

**Known today as.** The bark and leaves of *Salix alba*.

Kind: Plant  
Qualities: Cold and dry (Galenic tradition).

## What was it used for?

Cooling and binding: the bark for agues, the leaves for pains and bleeding.

## What does modern science say?

Its salicin is converted in the body to salicylic acid; aspirin, marketed in 1899, was made from the same chemistry.

## Pharmacognosy and toxicology

- **salicin**: a prodrug
- **salicylic acid**: its metabolite

**Mechanism.** Salicylic acid inhibits the cyclo-oxygenases only weakly in the test tube, by less than half at 10 M, and does not acetylate them as aspirin does.

**Dose.** As aspirin; the bark holds about 1 per cent salicin.

**Standing.** Approved in Europe as a traditional remedy for low back pain.

## What lore surrounds it?

Its use is older than Edward Stone’s report of 1763: the Ebers Papyrus of about 1500 BC already recommends willow for aches and pains, making it one of the oldest remedies with a modern medicine, aspirin, to show for it.

## What did the older authorities say?

**Edward Stone.** The English clergyman reported to the Royal Society in 1763 that willow bark cured agues, reasoning that a remedy grows where the disease is found.

## Sources

- Stone, E. (1763). An account of the success of the bark of the willow in the cure of agues. *Philosophical Transactions* 53.
- National Institutes of Health, on the story of aspirin and the Ebers Papyrus.
- Vlachojannis, J. E., et al. (2009). “A systematic review on the effectiveness of willow bark.” *Phytotherapy Research* 23.

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*White willow.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-01. The Thinking Press. https://thethinkingpress.org/materia-medica/white-willow

Historical description, not medical advice.