# Guaiacum (Guaiacum officinale)

**Lignum vitae*, “wood of life”; *lignum sanctum**

**Known today as.** The wood and resin of *Guaiacum officinale* and *G. sanctum*.

Kind: Resin & Wood

## What was it used for?

A decoction of the wood, with sweating and fasting, against the French disease, syphilis.

## What does modern science say?

It does not cure syphilis. Its resin turns blue with blood, which gave medicine the guaiac test for hidden blood.

## Pharmacognosy and toxicology

- **guaiaconic acid**: a resin acid that turns blue on oxidation
- **guaiaretic acid**: a lignan
- **guaiacol**: from the wood’s distillation; the expectorant guaifenesin was derived from it

**Mechanism.** The resin is a mild diaphoretic and the decoction, with sweating and fasting, treated a disease that remits on its own, which is why it seemed to cure syphilis for a generation and made the Fuggers rich; nothing in it touches the spirochaete. Its two real legacies are guaifenesin, the cough expectorant synthesised from guaiacol, and the guaiac test for hidden blood in the stool, in which the blue reaction of guaiaconic acid with haem screened for bowel cancer from 1864 until the immunochemical test replaced it.

**Dose.** Safe at the old doses; the wood dust sensitises.

**Standing.** The guaiac faecal occult blood test (Hemoccult) is still in use; the wood is CITES Appendix II.

## What lore surrounds it?

Its names, *lignum vitae*, “wood of life,” and the Spanish *palo santo*, “holy stick,” show the reverence the wood attracted when it reached Europe as a cure for the French disease. The Renaissance goldsmith Benvenuto Cellini wrote of dosing himself with a decoction of it, and believed it had cured him.

## What did the older authorities say?

**Ulrich von Hutten.** The German knight, a sufferer, praised it in a famous treatise of 1519; he died of the disease four years later.

**The Fuggers.** The Augsburg bankers profited greatly from its import.

## Sources

- Hutten, U. von (1519). *De guaiaci medicina et morbo gallico*.
- Wikipedia, “Lignum vitae.”
- Greegor, D. H. (1967). “Diagnosis of large-bowel cancer in the asymptomatic patient.” *JAMA* 201.
- Munger, R. S. (1949). “Guaiacum, the holy wood from the New World.” *Journal of the History of Medicine and Allied Sciences* 4.

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

Historical description, not medical advice.