Hua Jiao
StarZanthoxylum bungeanum Maxim.
Traditionally used for
- Digestion
- Bowel health
- Pain & joints
- Skin
☯ TCM Properties
Warms the Middle Burner and Stops Pain; Expels Parasites; Relieves Itching; Dries Dampness; Descends Qi
Traditional Chinese Uses
Hua Jiao (Sichuan peppercorn, zanthoxylum pericarp) is a warm, pungent herb that warms the Spleen and Stomach, disperses cold and dampness, and kills intestinal parasites. It is used for cold abdominal pain, nausea, vomiting, and diarrhea from Spleen-Stomach cold and deficiency, as well as for roundworm infestations. Its characteristic numbing, tingling sensation distinguishes it from other pungent herbs and makes it the defining spice of Sichuan cuisine, where its medicinal warming and parasite-expelling properties have long informed its culinary use.
Western Herbalism Properties
Relationships
Full-screen graph →Click a node for details · double-click to expand it · Ctrl/⌘ + scroll or two fingers to zoom and pan.
Botanical Description
Zanthoxylum bungeanum, the Sichuan or Chinese prickly ash, is a deciduous, prickly shrub or small tree in the Rutaceae, native to central and western China and widely cultivated for its pungent fruit pericarp, known as Hua Jiao. It grows 3 to 7 meters tall, with greyish-brown bark studded with prominent, broad-based corky prickles and similar shorter prickles on the young branches. The alternate, pinnately compound leaves bear 5 to 13 ovate to ovate-lanceolate leaflets 2 to 7 cm long, with finely crenulate margins, distinct translucent oil glands and a rachis that is conspicuously winged or armed with small prickles. The plant is dioecious; flowers are small, yellow-green, four- to eight-parted, arranged in dense, short terminal panicles in spring. The fruit is a small, globose follicle 4 to 5 mm across, splitting at maturity to expose a shiny black seed; the dark red-brown, rugose pericarp is highly aromatic, contains hydroxy-alpha-sanshool and other amide alkaloids, and is responsible for the characteristic numbing-pungent quality of the spice.
Active Constituents
Hydroxy-alpha-sanshool
Unsaturated N-alkylamide (alkylamide)Concentration: The dominant alkylamide of the pericarp and the compound assayed as the numbing principle; content varies several-fold between cultivars and degrades on storage, on heating and in acid conditions
The cause of the drug's characteristic tingling numbness. It excites sensory neurons by inhibiting two-pore domain potassium channels of the KCNK family, which removes the leak current that holds those neurons quiet, and it also acts on TRPV1 and TRPA1. That combination explains both the buzzing paraesthesia and the local analgesic quality that underlies the traditional use for pain and for toothache.
Hydroxy-beta-sanshool and hydroxy-gamma-sanshool
Unsaturated N-alkylamidesGeometric and chain-length congeners of the principal sanshool that contribute to the pungency and share its degradation behaviour in acid and on heating. The alkylamide ratio differs between red Huajiao from Zanthoxylum bungeanum and green Huajiao from other Zanthoxylum species, and is used to tell them apart.
Limonene, linalool, beta-myrcene, sabinene and 1,8-cineole
Monoterpenes and monoterpene alcohols (essential oil of the pericarp)The volatile fraction of the pericarp, responsible for the aroma and for much of the antibacterial and antifungal activity reported for the fruit oil. Volatile content is highest in the fresh pericarp and falls with storage.
Flavonol glucosides (quercetin and kaempferol glycosides, including hyperoside)
Flavonol glycosidesThe main non-volatile polar constituents of the pericarp. They contribute antioxidant activity in assay and form part of the chromatographic fingerprint but are not the reason the drug is used.
⚠ Drug Interactions
Jiao Mu (the seed of Zanthoxylum, Zanthoxyli Semen)
Hua Jiao is the pericarp; Jiao Mu is the seed of the same fruit, and the two are separate entries in the materia medica with different actions. The pericarp carries the alkylamides and the volatile oil and is used to warm the middle burner, stop pain and expel parasites. The seed carries a fixed oil and is used to drive water downward for oedema and fluid accumulation, an indication the pericarp does not share. Analytical comparison of the seed oils of Zanthoxylum bungeanum and Zanthoxylum schinifolium shows a lipid drug quite unlike the pericarp. Because the two are separated by hand during processing, incompletely dehulled or poorly sorted material carries the other part as a contaminant.
Clinical note: Specify pericarp when ordering, and reject batches with a high proportion of black seeds. Do not substitute one for the other on the strength of the shared name Hua Jiao, and note that this database holds Jiao Mu as its own record.
Zanthoxylum schinifolium and Zanthoxylum armatum (green Huajiao, Qing Hua Jiao)
Red Huajiao from Zanthoxylum bungeanum and green Huajiao from Zanthoxylum schinifolium or Zanthoxylum armatum are traded and cooked interchangeably, and comparative analyses of their aroma constituents, alkylamides and numbing substances show consistently different profiles. Pharmacological findings attributed to Hua Jiao in the literature therefore need to be checked against which species was actually studied, since a great deal of the work on Zanthoxylum armatum is published under the same common names.
Clinical note: Confirm the binomial rather than the colour or the market name, and read pharmacological claims about Zanthoxylum with attention to the species tested.
Topical local anaesthetics and other agents acting on peripheral sensory nerves
Hydroxy-alpha-sanshool acts directly on sensory neuron excitability through two-pore potassium channel block and TRP channel activation, and this has been demonstrated electrophysiologically. Whether concurrent local anaesthetic or capsaicin exposure alters that effect has not been tested in humans; the practical concern is that sanshool paraesthesia can mask or mimic a drug effect being assessed clinically.
Clinical note: No dose change is indicated. Be aware that a patient using Hua Jiao heavily, especially in mouth rinses or topical preparations, may report tingling or numbness that has nothing to do with a prescribed medicine.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3–6 g | Daily | — | — | 中国药典 2020 【用法与用量】3～6g。外用适量，煎汤熏洗。 【性味与归经】辛，温。归脾、胃、肾经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
Two acrid-hot herbs that together strongly warm the middle burner, disperse cold and stop severe abdominal pain.
Severe epigastric and abdominal cold pain with vomiting and inability to eat.
Core pair of a classical formula — Da Jian Zhong Tang, Jin Gui Yao Lue (Zhang Zhongjing)
Sour and pungent-hot together calm roundworms and warm the middle, relieving abdominal pain and vomiting from roundworms with interior cold.
Roundworm reversal (hui jue) with cold extremities and colicky pain.
Core pair of a classical formula — Wu Mei Wan, Shang Han Lun (Zhang Zhongjing)
Evidence Tier
Strong evidence · 9 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
1
1 verified · 0 unverified
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
8
2 verified · 6 unverified
Show 8 studies
- Pungent agents from Szechuan peppers excite sensory neurons by inhibiting two-pore potassium channels
- Hydroxy-α-sanshool from the fruits of Zanthoxylum bungeanum Maxim. promotes browning of white fat by activating TRPV1 to induce PPAR-γ deacetylation
- Hydroxy-α-sanshool isolated from Zanthoxylum bungeanum attenuates learning and memory impairments in scopolamine-treated mice
- Aroma Constituents and Alkylamides of Red and Green Huajiao (Zanthoxylum bungeanum and Zanthoxylum schinifolium)
- Alkylamides from pericarps of Zanthoxylum bungeanum
- Flavonol glucosides in pericarps of Zanthoxylum bungeanum
- Degradation and transformation mechanisms of numbing substances: Hydroxyl-α-sanshool & hydroxyl-β-sanshool from Zanthoxylum bungeanum exposed to acid environment
- Quality characteristics and digestive behavior of seed oils from two Huajiao (Zanthoxylum bungeanum and Zanthoxylum schinifolium)
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Zanthoxylum bungeanum Maxim. (Rutaceae): A Systematic Review of Its Traditional Uses, Botany, Phytochemistry, Pharmacology, Pharmacokinetics, and Toxicology
The reference synthesis for this species specifically, covering the traditional indications, the alkylamide and volatile chemistry, the reported pharmacology and the toxicology. The pharmacological evidence it assembles is preclinical; there is no controlled human trial of Hua Jiao as a medicine.
Pungent agents from Szechuan peppers excite sensory neurons by inhibiting two-pore potassium channels
Establishes the mechanism of the sanshool tingle: the alkylamides inhibit KCNK-family two-pore domain potassium channels, removing the background leak current that keeps sensory neurons at rest and so causing them to fire. This is the pharmacological basis of the numbing quality that defines the drug.
Hydroxy-α-sanshool from the fruits of Zanthoxylum bungeanum Maxim. promotes browning of white fat by activating TRPV1 to induce PPAR-γ deacetylation
Shows that hydroxy-alpha-sanshool from Zanthoxylum bungeanum fruit activates TRPV1 and drives browning of white adipose tissue in a rodent model. It confirms TRPV1 as a second target of the alkylamide alongside the potassium channel effect; the metabolic finding is preclinical.
Hydroxy-α-sanshool isolated from Zanthoxylum bungeanum attenuates learning and memory impairments in scopolamine-treated mice
Reports that isolated hydroxy-alpha-sanshool reduces scopolamine-induced cognitive deficits in mice. An isolated-compound animal study with no clinical counterpart.
Aroma Constituents and Alkylamides of Red and Green Huajiao (Zanthoxylum bungeanum and Zanthoxylum schinifolium)
Compares the aroma volatiles and alkylamides of red Huajiao from Zanthoxylum bungeanum with green Huajiao from Zanthoxylum schinifolium, providing the analytical basis for keeping the two species apart.
Alkylamides from pericarps of Zanthoxylum bungeanum
Characterises the alkylamides of the pericarp specifically, which is the plant part that constitutes the drug Hua Jiao.
Flavonol glucosides in pericarps of Zanthoxylum bungeanum
Identifies the flavonol glucosides of the pericarp, completing the picture of the non-volatile polar chemistry of the drug.
Degradation and transformation mechanisms of numbing substances: Hydroxyl-α-sanshool & hydroxyl-β-sanshool from Zanthoxylum bungeanum exposed to acid environment
Tracks the breakdown of the two principal sanshools under acid conditions. It matters practically because the numbing constituents are labile: storage, heating and gastric acid all reduce the amount of intact alkylamide, so the potency of a given batch is not fixed.
Quality characteristics and digestive behavior of seed oils from two Huajiao (Zanthoxylum bungeanum and Zanthoxylum schinifolium)
Characterises the seed oils of the two Huajiao species, showing the seed to be a fixed-oil material chemically distinct from the alkylamide-bearing pericarp. It is the analytical basis for keeping Hua Jiao and Jiao Mu as separate drugs.
Historical Texts
Shen Nong Ben Cao Jing (Divine Husbandman's Classic of the Materia Medica)
Han dynasty, compiled by about 200 CEShang Han Lun (Treatise on Cold Damage), Zhang Zhongjing
Han dynasty, about 200 CEJin Gui Yao Lue (Essential Prescriptions of the Golden Cabinet), Zhang Zhongjing
Han dynasty, about 220 CEBen Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty, 1596References
- Okagu Innocent Uzochukwu; Ndefo Joseph Chinedum; Aham Emmanuel Chigozie; Udenigwe Chibuike. C.. Zanthoxylum Species: A Review of Traditional Uses, Phytochemistry and Pharmacology in Relation to Cancer, Infectious Diseases and Sickle Cell Anemia . Frontiers in Pharmacology (2021) [DOI]
- Hu Fei; Zhang Ai; Ji Zhong-Liang; Thakur Kiran. Effects of different extraction methods on the volatile components and numbing substances in red Huajiao (Zanthoxylum bungeanum Maxim.) and green Huajiao (Zanthoxylum armatum DC.) . Food Chemistry: X (2025) [DOI]
- Gong Youwen; Huang Yongfu; Zhou Ligang; Shi Xueyan. Chemical Composition and Antifungal Activity of the Fruit Oil of Zanthoxylum bungeanum Maxim. (Rutaceae) from China . Journal of Essential Oil Research (2009) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
📝 Notes
Public notes from the community and your own private notes on Hua Jiao.
No notes yet.