# Juniper (Juniperus communis)

**Juniperus*; French *genièvre**

**Known today as.** The berries and wood of *Juniperus communis*.

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

> **Caution.** Not for pregnancy or kidney disease.

## What was it used for?

The berries to provoke urine and warm the stomach; the wood and berries burnt against plague and foul air.

## What does modern science say?

A diuretic and carminative; its oil irritates the kidneys in excess. Genever and gin take their name and flavor from it.

## Pharmacognosy and toxicology

- **alpha-pinene**: 
- **terpinen-4-ol**: the diuretic
- **sabinene**: 

**Mechanism.** Terpinen-4-ol increases the filtration of the kidney; the old warning that the berries damage the kidney rests on experiments with the oil of a related species, and Schilcher and Heil (1994) found no evidence for it at ordinary doses.

**Dose.** The oil irritates the kidney in large amounts; the berries flavour gin without harm.

**Standing.** Approved in Germany for dyspepsia; the European monograph allows it for mild urinary complaints.

## What lore surrounds it?

In Scotland juniper smoke was used in the saining, the ritual cleansing of house and byre at the New Year. See also [Savin](https://thethinkingpress.org/materia-medica/savin), its dangerous cousin.

The “juniper tree” that shelters Elijah in the King James text of 1 Kings 19 translates the Hebrew *rotem*, which modern scholarship identifies as the broom shrub, *Retama raetam*, not juniper at all. True juniper has a folklore of its own: its smoke was burned in Central European spring rites to drive out witchcraft, and in plague years communities burned juniper wood for its believed purifying power.

## What did the older authorities say?

**Pliny.** “The juniper is of a warming and resolvent nature beyond all other plants.” Of its two species “the odour of either, burnt, repels the approach of serpents.” The seed “is good for pains in the stomach, chest, and sides; it dispels flatulency and sudden chills, soothes cough,” and the berries “taken in red wine, act astringently upon the bowels.” It is diuretic, enters aperient antidotes, and is prescribed for convulsions, griping pains and sciatica “either in a dose of four berries in white wine, or in the form of a decoction of twenty berries in wine.” Some, he adds, “rub the body with juniper berries as a preventive of the attacks of serpents.”

**Culpeper.** “This admirable solar shrub is scarce to be paralleled for its virtues”: the berries, hot in the third degree, are “a most admirable counter-poison, and as great a resister of the pestilence, as any growing,” and provoke urine exceedingly; country people who cannot draw the chemical oil may eat ten or a dozen ripe berries every morning fasting; the ashes of the wood rubbed on the gums for scurvy.

## Sources

- Dioscorides, *De materia medica*.
- Bible Hub, “Juniper-tree.”
- Trees for Life, on juniper mythology and folklore.
- Grieve, M. *A Modern Herbal*, “Juniper Berries.” As published on botanical.com.
- Pliny the Elder, *Natural History* 24.36, trans. J. Bostock & H. T. Riley (1855), Perseus Digital Library.
- Culpeper, N. (1653). *The Complete Herbal*, “Juniper Bush.” Project Gutenberg #49513.
- Schilcher, H., and Heil, B. M. (1994). “Nierentoxizität von Wacholderbeerzubereitungen.” *Zeitschrift für Phytotherapie* 15.

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

Historical description, not medical advice.