Herb library · Herb · Hyssopus officinalis
Hyssop
A bushy garden herb of the mint family, used for coughs, colds and sore throats. It has not been tested for those uses in people; its concentrated essential oil has caused seizures.
Serious warning
Hyssop essential oil can cause seizures. A 1981 clinical report described poisonings with convulsions from commercial sage, hyssop, thuja and cedar oils, and a 1999 neurology report lists hyssop among the essential oils that are powerful convulsants.
Traditional use
Hyssop is a fragrant, hot-tasting perennial of European gardens. Its leaves and flowering tops have been taken as a tea for coughs and chest complaints and gargled for sore throats, and today it is used for symptoms of the common cold and of stomach and breathing infections. Its essential oil is sold for aromatherapy and home remedies.
What studies show
- Insufficient
Coughs, colds and digestion: the sources read here report no trials in people. What is known in people is about harm from the essential oil, not about benefit from the herb.
Be careful of
Cautions
- AmountNever swallow hyssop essential oil or give it to a child. In animal tests its toxic effect built up with repeated small doses. The seizures in the reports came from absorbing the oils as home remedies.
- NoteThe herb is widely used, and LiverTox reports it has not been linked to liver injury.
- PregnancyThere is no safety information for pregnancy or breastfeeding.
- Ask a clinicianTalk with a clinician or pharmacist before using this if you take prescription medicines, are pregnant or breastfeeding, or are giving it to a child.
From the old books
What herbals and dispensaries of the past printed. History, in their words.
“Principally used in quinsy and other sore throats, as a gargle, combined with sage and alum, in infusion sweetened with honey.”
In scripture
Where the Bible names this plant, and which plant scholars think is meant.
Purify me with hyssop, and I will be clean. Wash me, and I will be whiter than snow.
You shall take a bunch of hyssop, and dip it in the blood that is in the basin, and strike the lintel and the two door posts with the blood that is in the basin. None of you shall go out of the door of his house until the morning.
Now a vessel full of vinegar was set there; so they put a sponge full of the vinegar on hyssop, and held it at his mouth.
The Hebrew ezov is one of the most argued-over plants in the Bible. Tristram (1898) records that savory and marjoram had been proposed and judged it most probably the caper bush (Capparis spinosa), which grows out of walls and cliffs, not a plant of the mint family at all; if he is right, it is not the garden hyssop on this page. H. B. Tristram, The Natural History of the Bible (1898), p. 457 (opens in a new tab)
Sources
- Hyssop (LiverTox) (opens in a new tab) · NIH · read September 25, 2026
- Toxicity of some essential plant oils. Clinical and experimental study (opens in a new tab) · NIH · read September 25, 2026
- Plant-induced seizures: reappearance of an old problem (opens in a new tab) · NIH · read September 25, 2026
Reviewed September 25, 2026.