Shui Zhi水蛭
Hirudo · Leech
Overview
The dried body of the medicinal leech, and the most forceful of the stasis-breaking medicinals in routine use. Salty and bitter, neutral in temperature and slightly toxic, it enters the Liver blood and is reserved for stasis that has hardened into masses or refuses to shift under gentler herbs. Because it is toxic it is given in small, practitioner-set doses, most often as a powder in capsules rather than in a full decoction.
Nature & Flavor
Salty, bitter · Neutral · Slightly toxicChannels
LiverTypical Dosage
1.5–3 g in decoctionActions
2 core actions
- Breaks blood stasis, dissolves massesFixed abdominal masses, amenorrhea from congealed blood, and long-standing stasis where the pain is stabbing and always in the same place. This is the herb of last resort in that group, classically paired with Tao Ren 桃仁 and Da Huang 大黄.
- Frees the channels after injury and strokeResidual stasis after trauma with darkened, swollen, painful tissue; hemiplegia and numbness lingering after a stroke, where stasis blocks the collaterals.
In Formulas
Formulas containing Shui Zhi
Indications & Clinical Uses
- Fixed abdominal masses and lumps attributed to congealed blood
- Amenorrhea from long-standing blood stasis
- Fixed stabbing pain after trauma, with dark swelling
- Numbness and hemiplegia persisting after stroke
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
This herb is toxic and belongs only in a prescription written for the individual patient — never in self-medication and never at an increased dose because results feel slow. It is contraindicated wherever there is bleeding or a tendency to bleed: peptic ulcer, low platelets, heavy periods, recent surgery or a bleeding disorder. Do not take it alongside anticoagulant or antiplatelet drugs such as warfarin, heparin, aspirin or clopidogrel without medical supervision, and stop it well before any planned procedure. It is also unsuitable where the picture is blood deficiency without real stasis. As an animal-derived product it can provoke an allergic reaction; stop it if rash, itching or swelling appears.
Contraindicated in pregnancy: Contraindicated in pregnancy — it breaks blood stasis forcefully and has been avoided from conception through delivery for as long as it has been in use.
For licensed practitioners’ reference only
References
- Shen Nong Ben Cao Jing《神农本草经》(classical source, public domain).
2. Bensky, Clavey & Stöger. Chinese Herbal Medicine: Materia Medica, 3rd ed.
3. 《中华人民共和国药典》.
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.