Herbs & Botanicals · Traditional toothache bark

Prickly Ash

Zanthoxylum americanum · also called Northern prickly ash, toothache tree, toothache bark, yellow wood, pepper wood

Prickly ash is a thorny North American shrub. Its bark was traditionally chewed for toothache and its berries used for poor circulation. No trial in people has tested it for any use, and the lab research is small. The key caution: it has had almost no safety testing, may raise stomach acid, and should be avoided in pregnancy.

General information, not medical advice. Last substantive update October 25, 2026 · Not medically reviewed. A named clinician has not signed off on this page. How this page is made

About Prickly Ash

Northern prickly ash (Zanthoxylum americanum) is a thorny shrub from North America. Its bark has been used for toothache, pain and cramps, and its berries for circulation. Almost no modern research exists, none in people, and safety is not established.

What it is

Northern prickly ash is a woody shrub of the citrus family. Native American healers used its bark and berries as medicine, which is why it is also called the toothache tree.

It is not the same as Sichuan pepper (a spice from a related species), southern prickly ash (also called Hercules club), or ash trees.

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What makes it distinctive

Lab work found light-activating furanocoumarins such as psoralen, mostly in the fruit and leaf and much less in the bark. It also holds coumarin-type compounds and lignans.

Its relatives in Asia contain tingling, mouth-numbing compounds called sanshools. We did not find proof that northern prickly ash bark has them.

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What people use it for

Traditionally the bark was chewed for toothache or boiled into a tea for cramps, and for muscle and joint pain. The berries were used for poor circulation. Long use is not proof that it works.

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What the research shows

The evidence is extremely thin. We found no trial in people for any use, and no animal study of pain or circulation. The few papers are lab studies. Extracts slowed fungi in dishes, an effect that tracked furanocoumarin content. They had weak or no effect on gonorrhoea bacteria. Compounds isolated from the plant slowed leukaemia cells in a dish.

Large reviews of the whole Zanthoxylum family describe promising lab activity, but they cover many species and do not show that northern prickly ash works.

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At a glance

Traditional uses history, not proof

Toothache (bark chewed or packed around the tooth)
Muscle and joint pain, arthritis
Intestinal cramps and upset stomach
Poor circulation, leg pain and cold fingers (berries)
Sore throat, wounds and infections

Studied for research

Toothache: tradition only, no trials
Circulation: tradition only, no trials
Pain and arthritis: tradition only, no trials
Fungal and bacterial infections: lab dishes only, mixed
Leukaemia cells: lab chemistry on isolated compounds

Main compounds

Furanocoumarins such as psoralen (mostly in fruit and leaf)
Pyranocoumarins such as xanthyletin
Lignans such as sesamin and asarinin
Alkaloids such as chelerythrine (reported by a summary)
Sanshool-type tingling amides (found in relatives; not confirmed in this species)

Common forms

Bark tea (decoction)
Chewed bark
Tincture
Capsules
Berries (fruit)

Research links: Antifungal constituents of northern prickly ash (2005) · Cytotoxic coumarins and lignans from northern prickly ash (2001) · Furanocoumarins and DNA copying, lab (2004) · Canadian First Nations plants against gonorrhoea bacteria, lab (2011) · Zanthoxylum genus review (2023) · Prickly ash research summary (EBSCO, 2024) · Natural Medicines monograph (via vital.ly) · Research Library · Genes & Biomarkers Library

The plant and its history

Accepted scientific name: Zanthoxylum americanum Mill.
Naming authority: Mill.
Common names: Northern prickly ash (English); Toothache tree (English); Toothache bark (English); Yellow wood (English); Pepper wood (English); Clavalier d'Amerique (French)
Botanical family: Rutaceae (citrus family)
Classification: Plantae > Sapindales > Rutaceae > Zanthoxylum > Zanthoxylum americanum
Native range: A woody shrub native to North America (Natural Medicines monograph). A precise range was not confirmed in a source we read.
Habitat: Not described in the sources read.
What the plant looks like: Roots: Not described.; Stems: Prickly stems (from the common name). Bark is the main medicinal part. Other details not described in the sources read.; Leaves: Leaves contain furanocoumarins (lab analysis).; Flowers: Not described.; Fruit: Berry-like fruit, called berries in traditional use; richer in furanocoumarins than bark.
Cultivation: Not verified.
Harvest and processing: Not described. Bark is dried and boiled as a tea or made into a tincture (research summary).
Look-alikes and adulterants: Name: Southern prickly ash / Hercules club (Zanthoxylum clava-herculis); Note: A separate accepted species (GBIF key 8681996). The drug reference tells readers not to confuse the two. Its safety is not covered here.; Name: Sichuan pepper / Chinese prickly ash (Zanthoxylum bungeanum); Note: A separate accepted species (GBIF key 7269010), used as a numbing spice. See our Szechuan pepper spice page. Spice-research findings on sanshools do not transfer directly to northern prickly ash bark.; Name: Ash trees (Fraxinus); Note: A different genus. The drug reference warns not to confuse them.
Sustainability and conservation: Not assessed here.

Traditional use and history history, not clinical proof

Tradition or era	Documented use	Source
Native American medicine (as described in a 2024 summary)	Bark for intestinal cramps, dry mouth, muscle and joint pain, toothache, nervous disorders, arthritis and leg ulcers; berries for circulatory problems such as intermittent claudication and Raynaud syndrome. Bark tea, tincture, or chewing the bark for tooth pain.	s-ebsco-2024
Modern herbal use	Sold as bark, capsules and tinctures for infections, sore throat, toothache and wounds. The drug reference says there is no good scientific evidence for these uses.	s-trc-2022

Traditional use shows how a plant was used. It does not show that a supplement works or is safe today.

What is inside, and how it may work

What the plant contains and how those compounds act in cells and animals. Laboratory and animal mechanisms are not proven effects in people.

Main compounds

Compound	Family	Where it is concentrated	Activity studied	Level of evidence
Psoralen PubChem 6199	furanocoumarin	fruit and leaf (much less in bark)	Light-activating; correlated with antifungal activity in the lab; possible sun-sensitivity concern. ^{1 11 10}	Laboratory research
8-Methoxypsoralen (methoxsalen) PubChem 4114	furanocoumarin	fruit and leaf (much less in bark)	Confirmed in extracts by HPLC; light-activating. ^{1 10}	Laboratory research
Imperatorin PubChem 10212	furanocoumarin	fruit and leaf (much less in bark)	Confirmed in extracts by HPLC. ^{1 10}	Laboratory research
Xanthyletin PubChem 65188	pyranocoumarin	isolated from plant material (part not stated in abstract)	Slowed leukaemia cells in a dish (IC50 3.84 ppm). ^{6 10}	Laboratory research
Xanthoxyletin PubChem 66548	pyranocoumarin	isolated from plant material (part not stated in abstract)	Slowed leukaemia cells in a dish (IC50 3.48 ppm). ^{6 10}	Laboratory research
Alloxanthoxyletin and dipetaline	pyranocoumarin	isolated from plant material (part not stated in abstract)	Slowed leukaemia cells in a dish (IC50 1.31 and 0.68 ppm). PubChem IDs were not looked up. ⁶	Laboratory research
Sesamin PubChem 72307	lignan	isolated from plant material (part not stated in abstract)	Slowed leukaemia cells in a dish (IC50 2.71 ppm). ^{6 10}	Laboratory research
Asarinin PubChem 101612	lignan	isolated from plant material (part not stated in abstract)	Slowed leukaemia cells in a dish (IC50 4.12 ppm). ^{6 10}	Laboratory research
Chelerythrine PubChem 2703	isoquinoline (benzophenanthridine) alkaloid	not stated	A research summary reports activity against resistant staph bacteria in test tubes and lists alkaloids as potentially toxic. Not traced to an original paper. ^{4 10}	Secondary source
Hydroxy-alpha-sanshool PubChem 10084135	alkamide (sanshool-type amide)	fruit coat of Sichuan pepper species	The main tingling compound in Zanthoxylum spices. Whether northern prickly ash bark or berries contain it was not confirmed in the sources read. ^{7 2 10}	Genus level

Mechanisms, receptors and pathways

Target or pathway	Gene or receptor	What was found	Level
Fungal growth	not specified	Antifungal activity of the extracts tracked closely with furanocoumarin content and depended on light. ¹	Laboratory research
DNA polymerisation	not specified	Psoralen and 5-methoxypsoralen inhibited DNA copying in a cell-free test, and husk extracts did so more strongly, suggesting other inhibitors too. ¹¹	Laboratory research
Tingling and numbing (genus-level)	TRPV1, TRPA1, KCNK channels	Sanshool-type amides cause tingling by acting on nerve ion channels. Shown in work on Chinese prickly ash and relatives, not on northern prickly ash. ^{7 2}	Genus level review
Leukaemia cell growth	not specified	Isolated pyranocoumarins and lignans reduced thymidine incorporation in HL-60 cells. ⁶	Laboratory research

Absorption, metabolism and elimination

Absorption: Not studied for northern prickly ash.
Distribution: Not studied.
Metabolism: Not studied.
Elimination: Not studied.
Bioavailability: Not established. One review of Chinese prickly ash sanshools says they are unstable and break down by oxidation; this may not apply to northern prickly ash.

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Isolated compounds versus whole extracts

All the lab chemistry comes from solvent extracts or isolated compounds (furanocoumarins, pyranocoumarins, lignans). Extract of the husk worked more strongly than the pure furanocoumarins, so whole-plant effects are not the sum of single compounds. Nothing links these results to a bark tea or tincture.

Nutritional composition

Northern prickly ash is a medicinal shrub, not a nutrient.

7benefits and uses looked at

12studies and sources checked

Very low certaintybest evidence rating found

3lab markers tracked in trials

3 very low certainty4 not enough evidence

What was looked at

The 7 benefits and uses checked for Prickly Ash, each with how strong the evidence is. Tap one to open it.

Toothache (traditional bark use)Not enough evidence
Circulation, leg cramps and cold fingers (traditional berry use)Not enough evidence
Muscle and joint pain, arthritis (traditional use)Not enough evidence
Infections and fungi (lab only)Very low certainty
Digestive complaints (traditional use; may worsen some)Not enough evidence
Slowing leukaemia cells in a dishVery low certainty
Interference with DNA copying in a test tubeVery low certainty

Lab markers tracked in the studies

Fungal growth inhibition in disk testsGonorrhoea bacteria minimum inhibitory concentrationLeukaemia cell growth (thymidine incorporation)

What is Prickly Ash good for?

What prickly ash has been used for and how strong the evidence is. Nothing here is proven in people.

ToothacheNot enough evidenceThe bark was chewed for tooth pain, but no trial was found. A drug reference says there is no good evidence. See a dentist for tooth pain. Circulation, leg pain and cold fingersNot enough evidenceA traditional use of the berries. No study was found, and these problems need a doctor. Muscle and joint pain, arthritisNot enough evidenceA traditional use. Reviews of the whole Zanthoxylum family mention pain and inflammation, but nothing specific to this plant has been tested in people. Infections and fungiVery low certaintyExtracts slowed fungi in test dishes, mostly the fruit and leaf. They had weak or no effect on gonorrhoea bacteria. Lab only. Digestive complaintsNot enough evidenceTraditionally used for cramps, but a drug reference warns it might raise stomach acid and says to avoid it with ulcers or bowel disease. Leukaemia cells and DNA (lab chemistry)Very low certaintyIsolated compounds slowed human leukaemia cells in a dish, and furanocoumarins interfered with DNA copying in a test tube. This is not a cancer treatment.

Benefits, one by one

Each card is a research question, not a promise. Tap a goal to filter. Open a card to see the studies, doses and limits.

Toothache (traditional bark use)

Not enough evidence

The bark has a long tradition in North America as a "toothache tree". It was chewed or packed around a sore tooth. We found no trial in people. Reference summaries say there is no good evidence it works.

4 studiesTraditionally bark chewed or held on the tooth; no tested product.

Studies, doses and limits

What the trials found

No human trial. A consumer drug reference says there is no good scientific evidence for toothache or sore throat. A research summary says there are no documented medical uses of the bark.

Results

No human results exist.

Effect sizes as reported

None available.

Why this rating

Tradition and a genus-level theory only. No trial of any kind in people for this species.

Form and dose studied

Traditionally bark chewed or held on the tooth; no tested product.

Who was studied

No data in any group. Not studied in children.

Limits

Numbing could hide pain from a real problem such as an abscess. Species mix-ups (northern prickly ash, southern prickly ash, Sichuan pepper) make claims hard to compare.

Why researchers looked

It gives the plant its folk name. Related prickly ash species in Asia contain compounds that cause tingling and numbness in the mouth, so numbing is the usual guess for how it might have worked.

Traditional use

The bark was chewed or packed around a sore tooth in Native American medicine, according to the sources we read. Long use is not proof that it works.

Proposed mechanism Pharmacological theory

Not shown for northern prickly ash. In the genus, sanshool-type amides cause tingling and numbness by acting on nerve ion channels. Whether northern prickly ash bark has them in useful amounts was not confirmed in anything we read.

A proposed mechanism does not show that the effect happens in people.

Mouth tingling or numbing is possible. See a dentist for tooth pain, especially with swelling or fever.

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Circulation, leg cramps and cold fingers (traditional berry use)

Not enough evidence

The berries were traditionally used for poor circulation, including leg pain when walking (intermittent claudication) and Raynaud syndrome. We found no trial of any kind. Do not treat these conditions with it.

2 studiesTraditionally berries or bark as tea or tincture; no tested product.

Studies, doses and limits

What the trials found

None. A research summary lists these as proposed uses only.

Results

No human results exist.

Effect sizes as reported

None available.

Why this rating

Traditional claim only. No study in people found.

Form and dose studied

Traditionally berries or bark as tea or tincture; no tested product.

Who was studied

No data.

Limits

Claudication and Raynaud syndrome can signal serious vascular disease that needs medical care.

Why researchers looked

A research summary lists circulation problems as a traditional use of the berries.

Traditional use

Bark and berries were taken as tea or tincture for a "cold", sluggish circulation.

Proposed mechanism Traditional use

No mechanism has been shown. The consumer drug reference we read does not mention circulation as a use.

A proposed mechanism does not show that the effect happens in people.

Coumarin-type compounds are present, but no bleeding or blood-thinner study was found. See the Safety tab.

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Muscle and joint pain, arthritis (traditional use)

Not enough evidence

The bark was used for muscle and joint pain and arthritis. Summaries describe pain-easing and anti-inflammatory ideas as promising, but no trial in people has tested it.

3 studiesNo tested product.

Studies, doses and limits

What the trials found

None for northern prickly ash. The 2021 genus review says Zanthoxylum species are used for inflammation and pain, but this is not specific to this plant.

Results

No human results exist.

Effect sizes as reported

None available.

Why this rating

Traditional use and genus-level lab work only.

Form and dose studied

No tested product.

Who was studied

No data.

Limits

Genus reviews mix many species; their findings cannot be applied to northern prickly ash.

Why researchers looked

It is one of the main traditional uses and fits the genus, where many species are used for pain and inflammation.

Traditional use

Bark tea or tincture for rheumatism and stiffness.

Proposed mechanism Pharmacological theory

Not shown for this species. Genus-wide reviews report anti-inflammatory activity in lab and animal studies of other Zanthoxylum species.

A proposed mechanism does not show that the effect happens in people.

Long-term safety is unknown.

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Infections and fungi (lab only)

Very low certainty

In test tubes, extracts of the leaf, fruit, stem, bark and root slowed several fungi. The strongest were fruit and leaf, which hold more of the light-activated furanocoumarins than the bark does. A separate screen found weak or no effect on gonorrhoea bacteria. Nothing has been tested in people.

3 studiesLab extracts of different plant parts; no tested human product.

Studies, doses and limits

What the trials found

None.

Results

All extracts inhibited at least eight of 11 fungi in disk tests; fruit and leaf strongest; fungal inhibition correlated with furanocoumarin content (r2 = 0.902). Gonorrhoea isolates: weak or no activity (MIC 256 ug/mL or more).

Effect sizes as reported

Correlation between furanocoumarin content and inhibition zones r2 = 0.902 (abstract).

Why this rating

Test-tube work only. Light-dependent activity of fruit and leaf does not translate to bark taken by mouth.

Form and dose studied

Lab extracts of different plant parts; no tested human product.

Who was studied

Not applicable.

Limits

Disk assays are a first screen. Furanocoumarins that work under light are the same compounds that raise skin sun-sensitivity concerns.

Why researchers looked

Prickly ash was used for wounds, sore throat and infections, so researchers tested whether it can slow microbes.

Traditional use

Used for wounds, sore throat and infections, according to the drug reference we read.

Proposed mechanism Laboratory research

Furanocoumarins (psoralen, 8-methoxypsoralen, imperatorin) linked closely to fungal inhibition, and activity depended on light. In a cell-free test these compounds interfered with DNA copying.

A proposed mechanism does not show that the effect happens in people.

The same furanocoumarins can make skin more sensitive to sun in other plants. See the Safety tab.

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Digestive complaints (traditional use; may worsen some)

Not enough evidence

The bark was used for intestinal cramps, gastritis and diarrhoea. No trial supports this, and a drug reference warns it might increase stomach acid. People with ulcers or inflammatory bowel disease are told to avoid it.

2 studiesNo tested product.

Studies, doses and limits

What the trials found

None. Two summaries advise avoiding it with ulcers or inflammatory bowel disease, the opposite of the traditional claim.

Results

No human results exist.

Effect sizes as reported

None available.

Why this rating

Traditional claim only; safety sources point the other way for some gut conditions.

Form and dose studied

No tested product.

Who was studied

People with ulcer, IBS, ulcerative colitis or Crohn disease are told to avoid it.

Limits

The acid claim comes from a secondary reference and no measurement of stomach acid was found.

Why researchers looked

Intestinal cramps are one of the older listed uses of the bark.

Traditional use

Bark tea for cramps and upset stomach.

Proposed mechanism Traditional use

Not established. A drug reference says it may raise stomach acid.

A proposed mechanism does not show that the effect happens in people.

See the Safety tab for gut effects.

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Slowing leukaemia cells in a dish

Very low certainty

Compounds isolated from northern prickly ash (four pyranocoumarins and two lignans) slowed the growth of human leukaemia cells in a dish. This is lab chemistry, not a cancer treatment, and tells us nothing about taking the bark.

1 studiesIsolated compounds in culture.

Studies, doses and limits

What the trials found

None.

Results

All six compounds slowed HL-60 cell growth. Dipetaline was the most active (IC50 0.68 ppm).

Effect sizes as reported

IC50 values 0.68 to 4.12 ppm (abstract).

Why this rating

Isolated compounds on one cell line.

Form and dose studied

Isolated compounds in culture.

Who was studied

Not applicable.

Limits

Cell-line results rarely carry over to people.

Why researchers looked

Researchers screen plant compounds for activity against cancer cells.

Traditional use

Not a traditional use.

Proposed mechanism Laboratory research

The compounds reduced a marker of DNA building (thymidine incorporation) in HL-60 cells.

A proposed mechanism does not show that the effect happens in people.

Do not use prickly ash to treat any cancer.

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Interference with DNA copying in a test tube

Very low certainty

Two furanocoumarins found in the plant, psoralen and 5-methoxypsoralen, interfered with DNA copying in a cell-free test. The husk extract did so more strongly than the pure compounds. This is a lab mechanism and also explains why these compounds are a safety concern.

1 studiesExtracts and pure compounds in a test tube.

Studies, doses and limits

What the trials found

None.

Results

Husk extracts inhibited DNA copying more than single or mixed furanocoumarins.

Effect sizes as reported

Not given in the abstract.

Why this rating

Cell-free lab assay.

Form and dose studied

Extracts and pure compounds in a test tube.

Who was studied

Not applicable.

Limits

A mechanism observation, not a health benefit.

Why researchers looked

To understand why the extracts stop fungi growing.

Traditional use

Not a traditional use.

Proposed mechanism Laboratory research

Furanocoumarins inhibit DNA polymerisation in a PCR-based assay, depending on the DNA base mix.

A proposed mechanism does not show that the effect happens in people.

Not tested in pregnancy. See the Safety tab.

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Connections to the rest of health

How Prickly Ash connects to the rest of our health knowledge graph. Every link says what kind of connection it is. A safety link (for example to the liver) is a warning, not a benefit. A study that merely mentions a topic never creates a benefit link.

Explore every connection: goals, body systems, organs, symptoms, genes

Kind of connection Connected to Search

A. Wellness goals

Connected to	Kind of connection	Evidence status	Context	Studies
Pain Relief	Traditional use	Not enough evidence	Toothache (traditional bark use): The bark has a long tradition in North America as a "toothache tree". It was chewed or packed around a sore tooth. We found no trial in people. Reference summaries say there is no good evidence it works. Muscle and joint pain, arthritis (traditional use): The bark was used for muscle and joint pain and arthritis. Summaries describe pain-easing and anti-inflammatory ideas as promising, but no trial in people has tested it.	^{12 4 2 7 9 8}
Oral Health	Traditional use	Not enough evidence	Toothache (traditional bark use): The bark has a long tradition in North America as a "toothache tree". It was chewed or packed around a sore tooth. We found no trial in people. Reference summaries say there is no good evidence it works.	^{12 4 2 7}
Circulation Support	Traditional use	Not enough evidence	Circulation, leg cramps and cold fingers (traditional berry use): The berries were traditionally used for poor circulation, including leg pain when walking (intermittent claudication) and Raynaud syndrome. We found no trial of any kind. Do not treat these conditions with it.	^{4 12}
Joint Support	Traditional use	Not enough evidence	Muscle and joint pain, arthritis (traditional use): The bark was used for muscle and joint pain and arthritis. Summaries describe pain-easing and anti-inflammatory ideas as promising, but no trial in people has tested it.	^{4 9 8}
Immune Support	Preliminary mechanism	Very low certainty	Infections and fungi (lab only): In test tubes, extracts of the leaf, fruit, stem, bark and root slowed several fungi. The strongest were fruit and leaf, which hold more of the light-activated furanocoumarins than the bark does. A separate screen found weak or no effect on gonorrhoea bacteria. Nothing has been tested in people. Interference with DNA copying in a test tube: Two furanocoumarins found in the plant, psoralen and 5-methoxypsoralen, interfered with DNA copying in a cell-free test. The husk extract did so more strongly than the pure compounds. This is a lab mechanism and also explains why these compounds are a safety concern.	^{1 11 3}
Digestive Support	Traditional use	Not enough evidence	Digestive complaints (traditional use; may worsen some): The bark was used for intestinal cramps, gastritis and diarrhoea. No trial supports this, and a drug reference warns it might increase stomach acid. People with ulcers or inflammatory bowel disease are told to avoid it.	^{4 12}
Cellular Health	Preliminary mechanism	Very low certainty	Slowing leukaemia cells in a dish: Compounds isolated from northern prickly ash (four pyranocoumarins and two lignans) slowed the growth of human leukaemia cells in a dish. This is lab chemistry, not a cancer treatment, and tells us nothing about taking the bark.	⁶

B. Body systems

Connected to	Kind of connection	Evidence status	Context	Studies
Oral Health	Biological association	Not enough evidence	Studied for: Toothache (traditional bark use)	^{12 4 2 7}
Nervous System	Biological association	Not enough evidence	Studied for: Toothache (traditional bark use)	^{12 4 2 7}
Cardiovascular System	Biological association	Not enough evidence	Studied for: Circulation, leg cramps and cold fingers (traditional berry use)	^{4 12}
Musculoskeletal System	Biological association	Not enough evidence	Studied for: Muscle and joint pain, arthritis (traditional use)	^{4 9 8}
Immune System	Biological association	Very low certainty	Studied for: Infections and fungi (lab only) Studied for: Slowing leukaemia cells in a dish	^{1 11 3 6}
Digestive System	Biological association	Not enough evidence	Studied for: Digestive complaints (traditional use; may worsen some)	^{4 12}

I. Biomarkers

Connected to	Kind of connection	Evidence status	Context	Studies
Fungal growth inhibition in disk tests	Biological association	Very low certainty	Measured in trials: lowered. A lab change is not the same as a health benefit.	¹
Gonorrhoea bacteria minimum inhibitory concentration	Biological association	Very low certainty	Measured in trials: no-change. A lab change is not the same as a health benefit.	³
Leukaemia cell growth (thymidine incorporation)	Biological association	Very low certainty	Measured in trials: lowered. A lab change is not the same as a health benefit.	⁶

K. Biological pathways

Connected to	Kind of connection	Evidence status	Context	Studies
TRPV1, TRPA1, KCNK (genus-level)	Preliminary mechanism	Genus level review	Targets of sanshool-type amides in Chinese prickly ash. Not shown for northern prickly ash.	⁷

L. Active compounds

Connected to	Kind of connection	Evidence status	Context	Studies
Psoralen		Very low certainty	A light-activating furanocoumarin found in the plant, mostly in fruit and leaf. Photosensitivity is a theoretical concern. A light-activating furanocoumarin found mostly in fruit and leaf extracts. Preparation or compound: fruit and leaf extracts	¹
Coumarins	Drug or supplement interaction	Not enough evidence	Pyranocoumarins were isolated from the plant. A bleeding or blood-thinner effect is theoretical and unstudied for this plant. Pyranocoumarins were isolated from the plant. A blood-thinner interaction is theoretical and unstudied. Preparation or compound: bark	⁶
Psoralen	Biological association	In vitro	Light-activating; correlated with antifungal activity in the lab; possible sun-sensitivity concern. Preparation or compound: fruit and leaf (much less in bark)	^{1 11 10}
8-Methoxypsoralen (methoxsalen)	Biological association	In vitro	Confirmed in extracts by HPLC; light-activating. Preparation or compound: fruit and leaf (much less in bark)	^{1 10}
Imperatorin	Biological association	In vitro	Confirmed in extracts by HPLC. Preparation or compound: fruit and leaf (much less in bark)	^{1 10}
Xanthyletin	Biological association	In vitro	Slowed leukaemia cells in a dish (IC50 3.84 ppm). Preparation or compound: isolated from plant material (part not stated in abstract)	^{6 10}
Xanthoxyletin	Biological association	In vitro	Slowed leukaemia cells in a dish (IC50 3.48 ppm). Preparation or compound: isolated from plant material (part not stated in abstract)	^{6 10}
Alloxanthoxyletin and dipetaline	Biological association	In vitro	Slowed leukaemia cells in a dish (IC50 1.31 and 0.68 ppm). PubChem IDs were not looked up. Preparation or compound: isolated from plant material (part not stated in abstract)	⁶
Sesamin	Biological association	In vitro	Slowed leukaemia cells in a dish (IC50 2.71 ppm). Preparation or compound: isolated from plant material (part not stated in abstract)	^{6 10}
Asarinin	Biological association	In vitro	Slowed leukaemia cells in a dish (IC50 4.12 ppm). Preparation or compound: isolated from plant material (part not stated in abstract)	^{6 10}
Chelerythrine	Biological association	Secondary source	A research summary reports activity against resistant staph bacteria in test tubes and lists alkaloids as potentially toxic. Not traced to an original paper. Preparation or compound: not stated	^{4 10}
Hydroxy-alpha-sanshool	Biological association	Genus level	The main tingling compound in Zanthoxylum spices. Whether northern prickly ash bark or berries contain it was not confirmed in the sources read. Preparation or compound: fruit coat of Sichuan pepper species	^{7 2 10}

Each connection is stored with the ingredient, the connected record, the kind of connection, the evidence status, the supporting studies, the preparation or compound involved, and a review date (last reviewed October 25, 2026).

Evidence at a glance: what changed in 3 lab markers

Tap a number to show only those markers. Counts are markers, not people.

Other21

The evidence

The research centre for Prickly Ash. Every record here was checked against PubMed or the publisher's page; we never list a study we have not verified.

Evidence by outcome

Toothache (traditional bark use) 4 studies Not enough evidence Circulation, leg cramps and cold fingers (traditional berry use) 2 studies Not enough evidence Muscle and joint pain, arthritis (traditional use) 3 studies Not enough evidence Infections and fungi (lab only) 3 studies Very low certainty Digestive complaints (traditional use; may worsen some) 2 studies Not enough evidence Slowing leukaemia cells in a dish 1 studies Very low certainty Interference with DNA copying in a test tube 1 studies Very low certainty

Bars show how many studies we found for each outcome, not how well it works. People are added up across trials only (reviews are not added, to avoid double counting).

How we rate evidence

High certainty

Several well-run trials or reviews agree; further research is unlikely to change the picture much.

Moderate certainty

Good trials point the same way, but some doubt remains.

Low certainty

Small, short or inconsistent trials. The finding could change with better research.

Very low certainty

Very little or very weak human data. Treat as a possibility only.

Mixed findings

Trials or reviews disagree with each other.

Not enough evidence

Not enough human research to say either way.

Evidence against

Good research found no benefit, or found harm.

We take the reviewers' own risk-of-bias and GRADE statements where they exist, and otherwise judge from study size, design, consistency, directness and whether a product matches what is sold. Many publications do not make evidence high. Method note: We built on our existing summary, read PubMed abstracts, and checked GBIF and PubChem. The EBSCO and Natural Medicines pages were opened and read. Genus-wide reviews are used only as background. Most studies were read as abstracts only.

Study library: every study we checked 12

Design Research type Plant part Year from Search

Study	Design	People	Product, dose, length	Result
Bafi-Yeboa 2005 Antifungal constituents of northern prickly ash, Zanthoxylum americanum Mill. Phytomedicine · PMID 15957372 · DOI	Laboratory research in-vitro	11 fungal strains in disk tests	Northern prickly ash (Zanthoxylum americanum) extracts of leaf, fruit, stem, bark and root leaf, fruit, stem, bark, root not given here not given here · vs none	All extracts inhibited at least eight of 11 fungal species in disk tests. Activity depended on light. Fruit and leaf extracts were the most active. Psoralen, 8-methoxypsoralen and imperatorin were confirmed in the extracts. Furanocoumarin content was high in fruit and leaf and low in bark and wood, and correlated with fungal inhibition (r2 = 0.902). Broad antifungal activity in the lab, linked to furanocoumarins Methods, limits and funding Outcomes: Fungal growth inhibition zones; furanocoumarin content by HPLC Limitations: Test-tube disk assay only. Light-dependent activity in a dish does not show that a bark preparation treats a fungal infection in a person. Funding and conflicts: Not stated in abstract Read: abstract
Chruma 2018 Polyunsaturated fatty acid amides from the Zanthoxylum genus - from culinary curiosities to probes for chemical biology. Nat Prod Rep · PMID 29299588 · DOI	Narrative review plant	Chemistry review of Zanthoxylum alkamides	Zanthoxylum alkamides (sanshool-type amides) fruit coat (pericarp) of several species not given here not given here · vs none	The review says the fruit coats of several Zanthoxylum species ("prickly ash") are used in Asian cooking, especially Sichuan cuisine, for tingling and numbing sensations caused by alkamides. It covers how these compounds are made in the lab and tested. Explains where the tingling comes from in the genus Methods, limits and funding Outcomes: Chemistry and biological evaluation of alkamides Limitations: The abstract does not say which species have which alkamides. It does not show that northern prickly ash bark numbs the mouth in the same way. Funding and conflicts: Not stated in abstract Read: abstract
Cybulska 2011 Extracts of Canadian first nations medicinal plants, used as natural products, inhibit Neisseria gonorrhoeae isolates with different antibiotic resistance profiles. Sex Transm Dis · PMID 21301385 · DOI	Laboratory research in-vitro	Gonorrhoea bacteria isolates in culture	Ethanol extract of prickly ash (Northern prickly ash (Zanthoxylum americanum)) among 14 Canadian plants as studied not given here not given here · vs none	Four of the 14 plants (bearberry, goldenseal, black cherry, roseroot) inhibited all isolates. Prickly ash had weak or no activity, with minimum inhibitory concentrations of 256 ug/mL or more. Weak or no activity against gonorrhoea bacteria in the lab Methods, limits and funding Outcomes: Minimum inhibitory concentration against Neisseria gonorrhoeae Limitations: Test-tube screen. The plant part was not given in the abstract. A negative lab screen for one bacterium. Funding and conflicts: Not stated in abstract Read: abstract
EBSCO CAM Review Board 2024 Prickly ash's therapeutic uses (Research Starter) EBSCO · Source	Narrative review plant	not applicable	Prickly ash (Zanthoxylum americanum) bark and berries bark, berries not given here not given here · vs none	Read 2026-10-25. Says the bark was traditionally used for intestinal cramps, dry mouth, muscle and joint pain, toothache and nervous disorders, and the berries for circulatory problems such as intermittent claudication and Raynaud syndrome. States there are no documented medical uses of the bark, no double-blind placebo-controlled trials, and that clinical studies in humans are severely lacking. Says the plant has not had a modern safety evaluation, contains potentially toxic alkaloids, and that safety is not established in young children, pregnancy, nursing or severe liver or kidney disease. Advises people with IBS, ulcerative colitis or Crohn disease to avoid it. Mentions chelerythrine activity against resistant staph bacteria in test tubes. not applicable Methods, limits and funding Outcomes: see results Limitations: Secondary consumer-level summary; the abstract-level claims were not checked against the original papers it lists. Funding and conflicts: not applicable Read: full-text
GBIF 2026 GBIF species match: Zanthoxylum americanum Mill. (key 3190089) GBIF · Source	Database record plant	not applicable	Northern prickly ash (Zanthoxylum americanum) whole plant not given here not given here · vs none	GBIF API on 2026-10-25: Zanthoxylum americanum Mill. is ACCEPTED (exact match), family Rutaceae, order Sapindales. Z. clava-herculis L. (key 8681996) and Z. bungeanum Maxim. (key 7269010) are separate accepted species. not applicable Methods, limits and funding Outcomes: see results Limitations: Taxonomy database record. NCBI Taxonomy was not checked. Funding and conflicts: not applicable Read: full-text
Ju 2001 Cytotoxic coumarins and lignans from extracts of the northern prickly ash (Zanthoxylum americanum) Phytother Res · PMID 11507740 · DOI	Laboratory research in-vitro	Human leukaemia (HL-60) cells in culture	Four pyranocoumarins (dipetaline, alloxanthoxyletin, xanthoxyletin, xanthyletin) and two lignans (sesamin, asarinin) isolated from Northern prickly ash (Zanthoxylum americanum) as studied not given here not given here · vs none	All six compounds reduced thymidine incorporation in HL-60 cells. Dipetaline was the most active (IC50 0.68 ppm), then alloxanthoxyletin (1.31), sesamin (2.71), xanthoxyletin (3.48), xanthyletin (3.84) and asarinin (4.12 ppm). Slowed leukaemia cell growth in a dish Methods, limits and funding Outcomes: Incorporation of tritiated thymidine (a marker of cell growth) Limitations: Isolated compounds on one cancer cell line. Not a treatment finding. Says nothing about whole bark or berries taken by mouth. Funding and conflicts: Not stated in abstract Read: abstract
Luo 2022 Composition, structure and flavor mechanism of numbing substances in Chinese prickly ash in the genus Zanthoxylum: A review. Food Chem · PMID 34731789 · DOI	Narrative review plant	Food-chemistry review of Chinese prickly ash	Sanshool-type unsaturated amides from Chinese prickly ash (Zanthoxylum bungeanum and relatives) fruit coat not given here not given here · vs none	Sanshool-based unsaturated amides are the main cause of the tingling. They are unstable and break down by oxidation. Different sanshools act on different ion channels (TRPV1, TRPA1 and KCNK). Sanshools cause tingling by acting on nerve ion channels (mostly in Chinese prickly ash) Methods, limits and funding Outcomes: Composition and tingling mechanism Limitations: About Chinese prickly ash as a spice, not northern prickly ash bark. Funding and conflicts: Not stated in abstract Read: abstract
Mutinda 2023 Ethnobotanical uses, phytochemistry and pharmacology of pantropical genus Zanthoxylum L. (Rutaceae): An update. J Ethnopharmacol · PMID 36513263 · DOI	Narrative review plant	Genus review (many species)	Zanthoxylum species (genus-wide) fruit, seed, twig, leaf, stem not given here not given here · vs none	Over 400 compounds have been isolated in the genus, including alkaloids, flavonoids, coumarins, lignans and amides. Lab and animal work showed anti-cancer, antimicrobial and other activities. The authors call for safety approval work, clinical trials and pharmacokinetic studies. Genus-level overview; clinical trials and safety work still needed Methods, limits and funding Outcomes: Ethnobotany, chemistry, pharmacology Limitations: Genus-wide. Claims that traditional uses are confirmed rest on lab and animal studies, not on trials in people. Funding and conflicts: Not stated in abstract Read: abstract
Okagu 2021 Zanthoxylum Species: A Comprehensive Review of Traditional Uses, Phytochemistry, Pharmacological and Nutraceutical Applications. Molecules · PMID 34209371 · DOI	Narrative review plant	Genus review (many species)	Zanthoxylum species extracts and compounds (genus-wide, not specific to northern prickly ash) various not given here not given here · vs none	The review says many Zanthoxylum species are used as food and for inflammation, pain, hypertension and brain conditions. It reports over 500 isolated compounds and says the extracts show promising activity that deserves more research. Some active compounds have not been identified. Genus-level overview; promising lab activity Methods, limits and funding Outcomes: Traditional uses, compounds, lab and animal activity, toxicity Limitations: Covers the whole genus and a focus on metabolic and neuronal health. It does not give species-level evidence for northern prickly ash. Funding and conflicts: Not stated in abstract Read: abstract
PubChem (NCBI) 2026 PubChem compound records for prickly ash constituents PubChem · Source	Database record plant	not applicable	Psoralen, methoxsalen, imperatorin, sesamin, asarinin, xanthyletin, xanthoxyletin, chelerythrine, hydroxy-alpha-sanshool various not given here not given here · vs none	PubChem name lookups on 2026-10-25 returned CIDs: psoralen 6199, methoxsalen (8-methoxypsoralen) 4114, imperatorin 10212, sesamin 72307, asarinin 101612, xanthyletin 65188, xanthoxyletin 66548, chelerythrine 2703, hydroxy-alpha-sanshool 10084135. not applicable Methods, limits and funding Outcomes: see results Limitations: Records confirm the compounds exist; they do not say how much is in any one plant. Funding and conflicts: not applicable Read: full-text
Smith 2004 Inhibition of DNA polymerization and antifungal specificity of furanocoumarins present in traditional medicines. Photochem Photobiol · PMID 15291300 · DOI	Laboratory research in-vitro	Cell-free PCR assay	Psoralen, 5-methoxypsoralen and husk extracts of Northern prickly ash (Zanthoxylum americanum) husk (fruit coat) not given here not given here · vs none	Psoralen and 5-methoxypsoralen inhibited DNA copying in the test, in different ways depending on how AT-rich the DNA was. The prickly ash husk extracts inhibited it more than the single or mixed furanocoumarins, so other inhibitory compounds are likely present. Furanocoumarins interfered with DNA copying in a test tube Methods, limits and funding Outcomes: Inhibition of DNA polymerisation in a PCR-based assay Limitations: Cell-free assay. Shows that these compounds can act on DNA in the lab; not a result in people. Funding and conflicts: Not stated in abstract Read: abstract
Therapeutic Research Center 2022 Northern prickly ash monograph (Therapeutic Research Center, via vital.ly) Natural Medicines (via vital.ly) · Source	Authoritative guidance plant	not applicable	Northern prickly ash (Zanthoxylum americanum) bark, berries, root not given here not given here · vs none	Read 2026-10-25 (last updated 2022-11-21 per the page). Says there is no good scientific evidence for infections, sore throat, toothache, wounds or other uses, and not enough reliable information to know if it is safe or what the side effects are. Bark is "possibly unsafe" in pregnancy; berry and root safety is unknown. Not enough information for breastfeeding. It might raise stomach acid, so avoid with ulcer or other gut conditions. Lists minor interactions with antacids, H2-blockers and proton pump inhibitors. Lists no known herb or food interactions. Warns not to confuse it with ash, Chinese prickly ash or Hercules club. not applicable Methods, limits and funding Outcomes: see results Limitations: A commercial reference summary; it lists no anticoagulant interaction, but that is an absence of data, not proof of safety. Funding and conflicts: not applicable Read: full-text

What we do not know yet

No trial in people for any use.
No animal study of pain, inflammation or circulation.
No safety or toxicity study.
No test of bleeding, blood-thinner or sun-sensitivity effects.
Sanshool (mouth-numbing) content of this species not confirmed.
No EMA, NCCIH, LiverTox or LactMed record could be found.

How new research is added

New studies are found by a saved PubMed search and are placed in a review queue. A person reads each one before it changes any evidence rating or safety wording.

Lab markers

What changed in blood or saliva tests during trials. A changed number is not the same as feeling or being healthier, and we give no "normal ranges".

Other 3

▼

Fungal growth inhibition in disk tests

Lowered in trials

How far a plant extract stops a fungus growing around a paper disk in a dish.

Very low certainty

Results and what it means

Why it was measured

A first lab screen for antifungal activity.

Statistical vs. clinical meaning

Lab screen only; not a result in people.

Safety implication

None for people from this test.

Study	Result	People	Product
¹	Extracts of all five plant parts inhibited at least eight of 11 fungal species; fruit and leaf were most active.	11 fungal strains in culture	Northern prickly ash extracts (600 ug per disk)

●

Gonorrhoea bacteria minimum inhibitory concentration

No clear change in trials

The lowest extract level that stops a bacterium growing.

Very low certainty

Results and what it means

Why it was measured

A first lab screen for antibacterial activity.

Statistical vs. clinical meaning

A negative lab screen.

Safety implication

None.

Study	Result	People	Product
³	Prickly ash extract had weak or no activity (MIC 256 ug/mL or more) while four other plants worked at far lower levels.	Neisseria gonorrhoeae isolates	Ethanol extract of prickly ash

▼

Leukaemia cell growth (thymidine incorporation)

Lowered in trials

How much a cell line builds new DNA, used as a measure of growth.

Very low certainty

Results and what it means

Why it was measured

A first lab screen for anti-cancer activity.

Statistical vs. clinical meaning

Lab screen only.

Safety implication

None for people from this test.

Study	Result	People	Product
⁶	All six isolated compounds reduced thymidine incorporation; dipetaline was strongest.	HL-60 human leukaemia cells	Isolated pyranocoumarins and lignans from northern prickly ash

⁶

Safety

What studies and official sources say about side effects, medicines and who should check first. Each point shows what kind of evidence it comes from.

Main points to know 5

Almost no safety testing in people. A research summary says prickly ash has had no modern scientific safety evaluation and contains potentially toxic alkaloids, with unknown effects. A drug reference says there is not enough reliable information to know if it is safe or what the side effects are. Treat it as an unknown, not as a mild herb. Authoritative guidance ^{4 12}
Pregnancy and breastfeeding: avoid. The drug reference calls the bark possibly unsafe by mouth in pregnancy. Berry and root safety is unknown. For breastfeeding it says there is not enough information and advises staying on the safe side. Authoritative guidance ^{12 4}
Stomach and bowel conditions. The drug reference says it might raise stomach acid and advises against use with an ulcer or other gut condition. The research summary advises people with IBS, ulcerative colitis or Crohn disease to avoid it. These are statements from secondary sources; no measurement was found. Authoritative guidance ^{12 4}
Coumarin compounds: possible sun sensitivity and bleeding (theoretical). Lab work found furanocoumarins (psoralen, 8-methoxypsoralen, imperatorin) in the plant, mostly in fruit and leaf and much less in bark, and pyranocoumarins were isolated from it. Furanocoumarins such as psoralen are known light-activating compounds, and some coumarin-type compounds affect blood clotting in other plants. We found no report of skin reactions or bleeding in people using northern prickly ash, and the drug reference lists no blood-thinner interaction. This is a caution based on chemistry, not on a reported case. Pharmacological theory ^{1 6 12}
Mouth tingling or numbing. Prickly ash relatives are known for tingling and numbing of the mouth from sanshool-type amides. Whether northern prickly ash bark or berries do this, and how strongly, was not confirmed in the sources we read. Numbing can hide the signs of a dental infection. Pharmacological theory ^{2 7}

Side effects 4

Effect	How often	Severity and recovery	Evidence
Stomach upset or more stomach acid Stated as a possibility by the drug reference. No trial or case report was found.	Not established	mild to moderate (unknown) Unknown	Authoritative guidance ¹²
Mouth tingling or numbness Described for the spice relatives; not confirmed for northern prickly ash.	Not established	mild Expected to pass (not studied for this plant)	Pharmacological theory ^{2 7}
Skin more sensitive to sun (photosensitivity) Theoretical, from furanocoumarins found mainly in fruit and leaf. No case report for this plant was found.	Not established	unknown Unknown	Pharmacological theory ¹
Unknown effects of its alkaloids The research summary says the plant contains potentially toxic alkaloids and that harm is unknown.	Not established	unknown Unknown	Authoritative guidance ⁴

Liver

No human case of liver injury from northern prickly ash was found, but this is an absence of data, not proof of safety. We did not locate a LiverTox entry for it (not verified). The research summary says safety has not been established in people with severe liver or kidney disease. ⁴

How often. Unknown.

Monitoring. No official monitoring advice found. Yellow skin or eyes, dark urine or severe tiredness need prompt medical attention.

This is a safety connection. It is not evidence that Prickly Ash supports liver health.

Medicines and supplements 4

With	Why it matters	Importance	Evidence	What to do
Acid-reducing medicines (antacids, H2 blockers such as famotidine, proton pump inhibitors such as omeprazole) prescription	If prickly ash raises stomach acid, it could weaken these medicines.	Rated minor by the drug reference. Based on a theory, not a study.	Authoritative guidance Very low certainty ¹²	Tell your pharmacist if you use acid-reducing medicines and are thinking of prickly ash.
Blood thinners and antiplatelet medicines (warfarin, apixaban, aspirin, clopidogrel) and other medicines or herbs that affect bleeding prescription	The plant contains coumarin-type compounds. Some coumarins affect clotting in other plants, but no clotting effect has been shown for northern prickly ash.	Unknown. The drug reference lists no such interaction, and no study or case report was found. A theoretical caution only.	Pharmacological theory Not enough evidence ^{6 12}	If you take a blood thinner, or are due for surgery or dental work, ask your doctor or pharmacist before using it. Do not stop or change your medicine on your own.
Medicines or products that make skin sensitive to sun (for example some antibiotics, retinoids, or psoralen treatments) prescription	Furanocoumarins are light-activating compounds, so effects could add up.	Unknown. Theoretical.	Pharmacological theory Not enough evidence ¹	Ask a pharmacist. Protect skin from strong sun if you use a fruit or leaf product.
Other herbs and foods herb-food	None identified.	The drug reference lists no known herb or food interactions. Absence of a listed interaction is not proof there is none.	Authoritative guidance Not enough evidence ¹²	Tell your pharmacist about all supplements you use.

Who should check first 6

Situation	Advice	Evidence
Pregnancy	Avoid. The drug reference calls the bark possibly unsafe in pregnancy and says berry and root safety is unknown.	Authoritative guidance ^{12 4}
Breastfeeding	Avoid. There is not enough information and the drug reference advises staying on the safe side. No LactMed entry was found (not verified).	Authoritative guidance ¹²
Ulcer, gastritis, IBS, ulcerative colitis or Crohn disease	Avoid. The sources say it might raise stomach acid or worsen these conditions.	Authoritative guidance ^{12 4}
Babies and young children	Avoid. Safety in young children has not been established.	Authoritative guidance ⁴
Severe liver or kidney disease	Avoid. Safety has not been established.	Authoritative guidance ⁴
Taking blood thinners, a bleeding disorder, or planned surgery or dental work	Ask a doctor or pharmacist first. This is a precaution based on chemistry; no reports of bleeding were found.	Pharmacological theory ^{6 12}

Overdose, product quality and regulators

Summary. No toxicity study of northern prickly ash in animals or people was found. The only statement is from a research summary: the plant contains potentially toxic alkaloids, with unknown effects.

Animal. No animal toxicity study was found.

Human doses studied. Not given here.

High dose or long term signals. No long-term data of any kind.

Overdose response. Not described for this plant.

Genotoxicity. Not found in the sources read. In a cell-free test, furanocoumarins from the plant interfered with DNA copying; this is a lab observation and not a finding of genetic damage in people.

Toxic plant parts. Fruit and leaf were much richer in furanocoumarins than bark and wood in a lab analysis. Which part is safest is unknown.

The main risk is getting the wrong plant or an unstandardised product.

Mix-up with look-alike plants and spices. The drug reference warns not to confuse northern prickly ash with ash trees, Chinese prickly ash or Hercules club. Hercules club is southern prickly ash (Zanthoxylum clava-herculis); Chinese prickly ash or Sichuan pepper is Zanthoxylum bungeanum. These are accepted separate species in GBIF. Their effects and safety are not the same and cannot be assumed to match. ^{12 5}

Product content not standardised. Our existing summary notes that capsule and tincture content and species are not standardised. A lab analysis found that fruit, leaf and bark differ a lot in furanocoumarin content, so the plant part matters. ^{1 4}

Body	Action	Date
Natural Medicines (Therapeutic Research Center) (USA)	Monograph says safety and effectiveness are not established; bark possibly unsafe in pregnancy; avoid with stomach or gut conditions. source	2022

When to get medical help

Black or bloody stools, vomiting blood, or severe stomach pain
Unusual bruising, nosebleeds that will not stop, or bleeding gums (especially if you take a blood thinner)
Severe sunburn-like rash or blistering of skin exposed to sun
Swelling of the face or mouth, trouble breathing, or hives
Yellow skin or eyes, dark urine or pale stools
A toothache with swelling, fever or a bad taste: see a dentist rather than numbing the pain

Stop the supplement and contact a clinician or emergency service. In the US, Poison Control is 1-800-222-1222.

General information only, not medical advice. Ask a clinician or pharmacist before use, especially with medicines, in pregnancy or with a health condition. See the Natural Remedy Safety guide.

Frequently asked questions

What is northern prickly ash?

A thorny North American shrub, Zanthoxylum americanum. The bark has been used traditionally for toothache and the berries for circulation.

^{12 5}

Does it help toothache?

It is a traditional use, but we found no trial. A drug reference says there is no good evidence. See a dentist, because numbing could hide an infection.

^{12 4}

Does it improve circulation?

No study was found. It is a traditional use of the berries only. Leg pain when walking or cold, colour-changing fingers need a doctor.

⁴

Does it treat infections?

Not proven. Extracts slowed fungi in test dishes, but they had weak or no effect on gonorrhoea bacteria, and nothing was tested in people.

^{1 3}

Does it fight cancer?

No. Isolated compounds slowed leukaemia cells in a dish. That is early lab chemistry and not a treatment.

⁶

Is it safe in pregnancy or breastfeeding?

Avoid it. A drug reference calls the bark possibly unsafe in pregnancy and says there is not enough information for breastfeeding.

^{12 4}

Is it safe for children?

Safety in young children has not been established, so avoid it.

⁴

Can it interact with blood thinners?

No interaction is listed by the drug reference and no study was found. But the plant contains coumarin-type compounds, so ask your doctor or pharmacist if you take warfarin or other blood thinners. This is a caution, not a reported problem.

^{12 6}

Can it make skin sensitive to sun?

This is possible in theory. Fruit and leaf extracts were rich in light-activating furanocoumarins, with much less in bark. We found no report in people.

Will it numb my mouth like Sichuan pepper?

Sichuan pepper gets its tingle from sanshool compounds. We did not find proof that northern prickly ash bark has them, so we cannot say how strongly, if at all, it numbs.

^{7 2}

Is it the same as Sichuan pepper or southern prickly ash?

No. They are separate species with their own safety facts. Sichuan pepper is Zanthoxylum bungeanum and southern prickly ash (Hercules club) is Zanthoxylum clava-herculis.

^{5 12}

Is there a safe amount to take?

We cannot give amounts because no tested amount exists. Ask a doctor or pharmacist before using it.

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Editorial transparency

Written by: AlternativeMed editorial team. Research compiled with AI assistance, then checked against PubMed records.
Medical review: None. This page has not been reviewed by a physician or pharmacist.
First published: 2026-10-25
Last substantive update: 2026-10-25
How we research: We built on our existing summary, read PubMed abstracts, and checked GBIF and PubChem. The EBSCO and Natural Medicines pages were opened and read. Genus-wide reviews are used only as background. Most studies were read as abstracts only.
How we rate evidence: See "How we rate evidence" in the Evidence tab.
Independence: No product is promoted on this page. No affiliate links are shown. If one is added later it will be labelled and kept apart from the evidence.

Sources 12

Each source was opened and checked. Where we read only the abstract, it says so. The small numbers in the text point here.

Bafi-Yeboa NF, Arnason JT, Baker J, Smith ML. Antifungal constituents of northern prickly ash, Zanthoxylum americanum Mill.. Phytomedicine. 2005. PMID 15957372. DOI 10.1016/j.phymed.2003.12.005. (abstract)
Chruma JJ, Cullen DJ, Bowman L, Toy PH. Polyunsaturated fatty acid amides from the Zanthoxylum genus - from culinary curiosities to probes for chemical biology.. Nat Prod Rep. 2018. PMID 29299588. DOI 10.1039/c7np00044h. (abstract)
Cybulska P, Thakur SD, Foster BC, Scott IM, Leduc RI, Arnason JT. Extracts of Canadian first nations medicinal plants, used as natural products, inhibit Neisseria gonorrhoeae isolates with different antibiotic resistance profiles.. Sex Transm Dis. 2011. PMID 21301385. DOI 10.1097/OLQ.0b013e31820cb166. (abstract)
EBSCO CAM Review Board. Prickly ash's therapeutic uses (Research Starter). EBSCO. 2024. (full-text)
GBIF. GBIF species match: Zanthoxylum americanum Mill. (key 3190089). GBIF. 2026. (full-text)
Ju Y, Still CC, Sacalis JN, Li J, Ho CT. Cytotoxic coumarins and lignans from extracts of the northern prickly ash (Zanthoxylum americanum). Phytother Res. 2001. PMID 11507740. DOI 10.1002/ptr.686. (abstract)
Luo J, Ke J, Hou X, Li S, Luo Q, Wu H. Composition, structure and flavor mechanism of numbing substances in Chinese prickly ash in the genus Zanthoxylum: A review.. Food Chem. 2022. PMID 34731789. DOI 10.1016/j.foodchem.2021.131454. (abstract)
Mutinda ES, Kimutai F, Mkala EM, Waswa EN, Odago WO, Nanjala C. Ethnobotanical uses, phytochemistry and pharmacology of pantropical genus Zanthoxylum L. (Rutaceae): An update.. J Ethnopharmacol. 2023. PMID 36513263. DOI 10.1016/j.jep.2022.115895. (abstract)
Okagu IU, Ndefo JC, Aham EC, Udenigwe CC. Zanthoxylum Species: A Comprehensive Review of Traditional Uses, Phytochemistry, Pharmacological and Nutraceutical Applications.. Molecules. 2021. PMID 34209371. DOI 10.3390/molecules26134023. (abstract)
PubChem (NCBI). PubChem compound records for prickly ash constituents. PubChem. 2026. (full-text)
Smith ML, Gregory P, Bafi-Yeboa NF, Arnason JT. Inhibition of DNA polymerization and antifungal specificity of furanocoumarins present in traditional medicines.. Photochem Photobiol. 2004. PMID 15291300. DOI 10.1562/2003-12-10-ra.1. (abstract)
Therapeutic Research Center. Northern prickly ash monograph (Therapeutic Research Center, via vital.ly). Natural Medicines (via vital.ly). 2022. (full-text)

Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.