Herb library · Herb · Zanthoxylum americanum, Zanthoxylum clava-herculis
Prickly ash
A spiny North American shrub, the "toothache tree", whose pungent bark and berries were a favorite of 1800s American doctors. It has not been studied in people.
Traditional use
Northern prickly ash grows in thickets and river banks from Virginia to Canada and west to the Mississippi; southern prickly ash grows further south. The bark and berries were important remedies of the American Eclectic physicians, and its reputation for toothache gave the plant its common name.
What studies show
No studies in people of this herb on its own yet. What is known of it comes from the traditions that use it.
- Insufficient
Toothache and other uses: no studies in people were found. Lab studies found an alkaloid from southern prickly ash bark active against drug-resistant staph bacteria, which does not show what the bark does in people.
Be careful of
Cautions
- NoteSouthern prickly ash bark has poisoned cattle; a study of its extracts found toxins that act on the junction between nerves and muscles. There is no safety research in people.
- PregnancyIts safety in pregnancy and breastfeeding is unknown.
- 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.
“Its reputed efficacy in toothache has given it the name of Toothache tree.”
“All parts of the shrub are aromatic and pungent, and the leaves and berries have a decided odor of lemons.”
Sources
- Neuromuscular effects of toxins isolated from southern prickly ash (Zanthoxylum clava-herculis) bark (1996) (opens in a new tab) · NIH · read September 25, 2026
- Activity of Zanthoxylum clava-herculis extracts against multi-drug resistant methicillin-resistant Staphylococcus aureus (2003) (opens in a new tab) · NIH · read September 25, 2026
Reviewed September 25, 2026.