# Hyssop (Hyssopus officinalis)

*Greek *hyssopos*; Hebrew *ezov**

**Known today as.** *Hyssopus officinalis*; the hyssop of Scripture was probably a wild marjoram, *Origanum syriacum*.

Kind: Plant  
Qualities: Hot and dry (Galenic tradition).  
Poisoning: Convulsant terpenes (thujone, pinocamphone, camphor) (https://thethinkingpress.org/materia-medica/poisons/convulsant-terpenes)

## What was it used for?

For coughs and the chest, in syrups and decoctions.

## What does modern science say?

Its oil contains pinocamphone, which can cause seizures in excess; the herb itself is mild. A tea of the leaf is safe and mildly expectorant; the distilled oil contains pinocamphone, which has caused convulsions in children given a few drops and in adults who took it for epilepsy, and France restricts its sale.

## Pharmacognosy and toxicology

- **pinocamphone**: 
- **isopinocamphone**: 

**Mechanism.** The pinocamphones are convulsant at the GABA-A receptor.

**Dose.** A few drops of the oil have convulsed children; the tea is safe.

**Standing.** The oil is restricted in France; the herb is a food.

## What lore surrounds it?

The herb of purification, it joins the materia medica to the rite: see [Holy water](https://thethinkingpress.org/materia-medica/holy-water).

The hyssop of Scripture is a puzzle, since *Hyssopus officinalis* does not grow in Palestine: the Syrian oregano, *za’atar*, is the likeliest, and the caper is the other candidate for the hyssop that “springeth out of the wall.” Hyssop was strewn in sickrooms against the plague, and Gerard says the Hebrews used it in the baths.

## What did the older authorities say?

**Exodus.** A bunch of hyssop was dipped in the blood of the Passover lamb to mark the doorposts.

**Psalm 51.** “Purge me with hyssop, and I shall be clean”: the verse sung as *Asperges me* while holy water is sprinkled before Mass.

**Hippocrates.** Gives hyssop for the chest and pleurisy, and Dioscorides with figs and honey for the cough and the breath.

**The Benedictines.** Grew it in every cloister garden, and it is among the hundred and thirty herbs of the Chartreuse liqueur of the Carthusians, whose recipe of 1605 is still kept by the monks.

## Sources

- Exodus 12:22.
- Psalm 51 (Vulgate 50).
- Grieve, M. *A Modern Herbal*, “Hyssop.” As published on botanical.com.
- 1 Kings 4:33.
- Millet, Y., et al. (1981). “Toxicity of some essential plant oils: clinical and experimental study.” *Clinical Toxicology* 18.
- Millet, Y., et al. (1981). *Clinical Toxicology* 18.

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

Historical description, not medical advice.