Prickly Ash Bark

The bark of a North American shrub in the citrus family, used in Indigenous and frontier folk herbalism and botanically related to Sichuan pepper.

Last reviewed: February 9, 2026

Overview

Prickly ash (Zanthoxylum americanum and Zanthoxylum clava-herculis) is a thorny shrub or small tree native to eastern North America, belonging — unexpectedly — to the Rutaceae, the citrus family. The bark and berries produce a distinctive tingling, numbing sensation on the tongue, which earned it the folk name "toothache tree." The plant is a close relative of Sichuan pepper (Zanthoxylum bungeanum), and the same mouth-numbing compound family — the alkylamides, particularly hydroxy-alpha-sanshool — is present in both. Prickly ash bark has a long history in Indigenous North American and early settler herbalism, where it appeared in a wide range of folk preparations.

This page provides educational context on prickly ash bark's identity, traditional background, and safety considerations.

What it is

Prickly ash bark refers to the dried bark (and sometimes berries) of Zanthoxylum americanum (Northern prickly ash) or Zanthoxylum clava-herculis (Southern prickly ash). It may appear as:

dried bark strips or cut pieces for decoction or infusion
tinctures or liquid extracts
capsules or powdered supplements
an ingredient in traditional herbal formulas and historical bitters blends

The bark has a sharp, peppery, slightly bitter taste that transitions into a tingling numbness — a sensory signature shared with its Sichuan pepper relatives. The berries carry a similar but more concentrated profile.

Traditional use (educational)

Prickly ash bark has a concentrated presence in North American folk traditions:

Indigenous peoples of eastern North America referenced prickly ash bark and berries in a variety of practical contexts, including as a chewing preparation for mouth discomfort — the "toothache tree" name reflects this specific folk association
early American settler herbalism adopted prickly ash extensively; it appeared in numerous 19th-century domestic remedy books and was a component of some early proprietary herbal formulas
Eclectic physicians in the 19th and early 20th centuries discussed prickly ash bark frequently in their materia medica, particularly in circulatory and digestive contexts
the berries have been used as a spice and flavoring agent, overlapping with the culinary use of the related Sichuan pepper

These references describe cultural and historical use patterns, not proven clinical outcomes.

What research says

Formal research on prickly ash bark is limited. Phytochemical studies have identified alkylamides (including hydroxy-alpha-sanshool), coumarins, and lignans as notable constituents. The alkylamides are responsible for the characteristic tingling-numbing sensation and have attracted some pharmacological interest, primarily in the context of sensory receptor interactions. However, clinical trials on prickly ash bark preparations are essentially absent. The gap between extensive folk use and formal evidence is wide, and the plant remains largely unstudied by modern clinical standards.

Safety & interactions

Common safety considerations include:

prickly ash bark consumed in traditional beverage or flavoring amounts has a long track record, though formal safety studies are lacking
the alkylamide content produces noticeable oral tingling and numbness, which can be alarming to those unfamiliar with the sensation but is a well-known property of the plant family
coumarin compounds are present in some Zanthoxylum species, raising theoretical considerations about interactions with anticoagulant medications
concentrated extracts and tinctures carry higher alkylamide exposure than simple bark preparations

Who should be cautious

Caution is commonly advised for:

individuals taking anticoagulant or antiplatelet medications (coumarin content introduces theoretical interaction considerations)
pregnant or breastfeeding individuals (formal safety data is absent for these populations)
people with known allergies to Rutaceae family plants (citrus relatives)
anyone unfamiliar with the numbing-tingling effect, who may mistake the normal alkylamide response for an allergic reaction

Quality & sourcing considerations

Quality factors often discussed include:

species identification matters — Zanthoxylum americanum and Zanthoxylum clava-herculis are the North American species of herbal tradition, distinct from Asian Zanthoxylum species
bark harvesting practices and plant part (bark vs. berry) affect the chemical profile and potency
wildcrafted prickly ash is more common than cultivated, introducing variability in growing conditions and chemistry
products labeled generically as "prickly ash" without species identification create ambiguity for the consumer

FAQs

Is prickly ash the same as Sichuan pepper? They are close relatives in the Zanthoxylum genus and share the same tingling-numbing alkylamide compounds, but they are different species with different geographic origins and traditional contexts.
Why does it numb the mouth? The alkylamides in prickly ash — particularly hydroxy-alpha-sanshool — interact with sensory nerve receptors in the mouth, producing the characteristic tingling and numbing sensation. This is a well-known property of the plant family, not a sign of toxicity.
Is this page recommending prickly ash bark? No — this is educational information only.