Leech Shuihzi

Leech (Hirudo), Shui Zhi

Overview:
Shui Zhi, or leech, refers to the dried body of certain species of bloodsucking leeches, most commonly Hirudo nipponia. In Traditional Chinese Medicine (TCM), leeches have been used for centuries to invigorate blood, break up blood stasis, and address serious circulatory issues such as masses, clots, and traumatic injuries. Despite initial discomfort at the idea of using leeches, their medicinal value is both historically respected and increasingly supported by modern science.

Botanical & Zoological Characteristics:
Leeches are segmented, aquatic annelids known for their blood-feeding habits. The species used in Chinese medicine are typically farmed under controlled conditions, then dried for use in decoctions or powdered formulas.

Traditional Uses in TCM:

• Breaks up and removes blood stasis: Especially effective in treating amenorrhea (absence of menstruation), abdominal masses, or fixed, sharp pain due to blocked blood flow.

• Used in trauma recovery: Helps reduce bruising and swelling after injuries.

• Part of treatments for stroke or paralysis (when due to blood stasis): Often combined with other blood-invigorating herbs.

Pharmacological Properties:
Leech extracts contain biologically active substances such as hirudin, a potent natural anticoagulant that inhibits blood clotting and improves microcirculation. Modern studies suggest potential applications in treating thrombosis, cardiovascular disease, and even cancer-related blood stagnation.

Preparation and Dosage:
Shui Zhi is most often used in powdered form, as its active ingredients are not easily extracted through boiling. It is usually prescribed in combination with other herbs under the supervision of a trained TCM practitioner.

Precautions:

• Potent and not for casual use.

• Contraindicated in patients with bleeding disorders, pregnancy, or those currently taking anticoagulant medications.

• Should only be used under professional guidance due to its strong blood-moving effects.