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Xi Xin细辛

Asari Radix et Rhizoma · Manchurian Wild Ginger · Asarum Root

Herbs that Release the Exterior 解表药《神农本草经》

Overview

· Disperse Wind-Cold. Xi Xin is the dried root and rhizome of Asarum heterotropoides var. mandshuricum, A. sieboldii or A. sieboldii var. seoulense. Acrid, warm and classified as slightly toxic, it is the most penetrating herb in this chapter: it disperses cold at the surface, warms the Lung and breaks up thin watery mucus, opens the nose, and reaches the Shaoyin level, which is why it is reached for when cold has gone deep — a headache that bores into the skull, a toothache, an exterior pattern in a patient whose yang is already weak. Since the 2005 edition of the Chinese Pharmacopoeia only the underground parts are official, and the daily dose is capped; this is a small-dose herb by regulation as well as by tradition.

Nature & Flavor

Acrid · Warm · Slightly toxic

Channels

Lung · Kidney · Heart

Typical Dosage

1–3 g in decoction
细辛Photography for this entry is on its way.

Actions

4 core actions

  • Releases the exterior, disperses coldWind-cold exterior patterns, and above all the exterior pattern of a yang-deficient patient who feels the cold badly and cannot raise a sweat — the classical pairing with Ma Huang and Fu Zi.
  • Dispels wind, stops painBoring Shaoyin headache, toothache from wind-cold or from deficiency fire, and wind-cold-damp painful obstruction of the joints. Its reach into the head and face is why it recurs through the headache and facial-pain formulas.
  • Warms the Lung, transforms thin mucusCough and wheezing with copious clear watery sputum from cold fluids lodged in the Lung — the Ma Huang / Gan Jiang / Wu Wei Zi / Xi Xin core of Xiao Qing Long Tang.
  • Opens the nasal passagesBlocked nose, loss of smell, and the persistent discharge of, usually alongside Xin Yi and Bai Zhi.

In Formulas

Formulas containing Xi Xin

Indications & Clinical Uses

  • Wind-cold exterior pattern, especially where yang is weak and sweating will not come
    - Shaoyin headache; toothache from wind-cold or from deficiency fire
    - Wind-cold-damp painful obstruction with cold, aching joints
    - Cough and wheezing with copious thin, clear sputum
    - Nasal congestion, loss of smell, sinus discharge

Western Medical Keywords

Searchable condition terms

Common coldSinusitisToothacheNeuralgiaBronchitisAllergic rhinitis

Contraindications

Cautions

The dose is capped. The Chinese Pharmacopoeia limits Xi Xin to 1–3 g in decoction and 0.5–1 g per dose as a powder; the classical maxim 「」 — no more than one qian — says the same thing in older units. Powder is not interchangeable with a decoction at the same weight: in a decoction much of the volatile oil, which is the fraction responsible for the toxicity, is driven off, and a long boil is how higher classical doses were always handled.

Only the root and rhizome are official. From the 2005 Pharmacopoeia onward the medicinal part is the root and rhizome, not the whole plant. Aristolochic acid — a documented nephrotoxin and carcinogen — has been found in the above-ground parts of Asarum species, and it is the aerial material that carries that concern. Use only pharmacopoeia-grade from a supplier who tests for it; never material sold as whole herb.

Classical incompatibility: not combined with Li Lu 藜芦.

Wrong for heat and for deficiency. Avoid in yin-deficient dry cough, cough from Lung heat, spontaneous sweating from qi deficiency, and headache from Liver-yang rising — it is warming, drying and dispersing, and will make all of these worse.

Signs of too much — headache, vomiting, sweating, restlessness, palpitations, breathlessness — mean the herb should be stopped and medical advice sought. Xi Xin is not a self-prescribing herb; it belongs in a prescription written by a practitioner who can control the dose and the source.

Contraindicated in pregnancy: Not used in pregnancy. Xi Xin is acrid, warm, strongly dispersing and classified as slightly toxic, and it carries a legal dose ceiling; standard practice is to avoid it during pregnancy and while breastfeeding. Any exception is a decision for the treating practitioner alone.

For licensed practitioners’ reference only

References

  1. Shen Nong Ben Cao Jing《神农本草经》(classical source, public domain).
    2. 《中华人民共和国药典》— Asari Radix et Rhizoma: medicinal part (root and rhizome only) and the 1–3 g decoction ceiling.
    3. Bensky, Clavey & Stöger. Chinese Herbal Medicine: Materia Medica, 3rd ed.

Professional reference notice. Entries are scholarly references for licensed TCM practitioners and students — not medical advice, and not a recommendation to self-prescribe. Chinese herbal formulas should be used under the guidance of a qualified practitioner. Content is an original editorial compilation by Cura x Cura, cross-checked against the cited references.