Bi Ma Zi蓖麻子
Ricini Semen · Castor Bean · Castor Seed
Overview
- ·. Editions vary — some place the seed here, others with the harsh downward-draining purgatives.*
The mottled seed of the castor plant, sweet, acrid, neutral in nature and toxic. Pounded to a paste it draws toxin out of an abscess, softens scrofulous nodes and, in one of the more distinctive classical applications, was bound over an acupoint to lift what has sunk — for prolapse of the rectum or uterus, the sole of the foot for a retained placenta — and applied to the slack side of the face in facial paralysis. Small internal doses were used to move a blocked bowel. The seed contains ricin, one of the most poisonous proteins known; the expressed oil does not, because ricin does not pass into the oil. That distinction is the whole safety story of this entry.
Nature & Flavor
Sweet, acrid · Neutral · ToxicChannels
Large Intestine · LungTypical Dosage
2–5 g of the shelled seed internally, crushed or in pills and powders — the pharmacopoeia range, and a route rarely chosen. External use as a pounded paste in a compounded amount. Castor oil is a separate pharmaceutical product with its own dosing and is not this herb.Actions
4 core actions
- Draws out toxin, reduces swellingUnresolved boils and abscesses, scrofulous nodes, and swollen painful sores — the crushed kernel spread over the lesion as a poultice.
- Lifts what has sunk, applied to a pointThe classical topical use that gives the seed its reputation: bound over Bai Hui for rectal or uterine prolapse, and over Yong Quan on the sole for retained placenta. Both are practitioner procedures, applied briefly and removed.
- Opens a blocked bowelConstipation with stagnation, in the classical internal record. Contemporary practice uses pharmaceutical castor oil rather than the seed, and only where a stimulant laxative is actually indicated.
- Applied to a slack faceThe paste applied to the affected side in facial paralysis, and to the opposite side in some accounts. Recorded here as part of the classical practice; it is not a substitute for assessing a new facial weakness, which needs a diagnosis.
In Formulas
Formulas containing Bi Ma Zi
No published formula lists this herb yet — the library is growing.
Indications & Clinical Uses
- Unresolved boils, abscesses and scrofulous nodes — topical poultice
- Prolapse of rectum or uterus, retained placenta — classical point application, by a practitioner
- Facial paralysis, applied topically in the classical record
- Constipation with stagnation (classical internal use; the modern route is pharmaceutical castor oil)
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
Bi Ma Zi is toxic. The seed contains ricin, a protein that shuts down protein synthesis in the cells it enters; a small number of chewed seeds can kill a child and a modest number can kill an adult.
- Whole seeds swallowed intact often pass through; chewed seeds do not. Poisoning begins hours later with burning in the mouth and throat, severe vomiting and bloody diarrhoea, then dehydration and shock, with liver and kidney injury and, in serious cases, death several days after the exposure. There is no antidote — treatment is supportive, in hospital.
- Keep seeds away from children. They are attractive, mottled and bean-like, and the ornamental plant is common in gardens. Any suspected ingestion, at any age, is a medical emergency.
- The oil is not the seed. Ricin is not soluble in the oil and is left behind in the pressed cake, so pharmaceutical castor oil does not contain it. Do not reason from the safety of the oil to the safety of the seed, or the reverse.
- Internal use of the seed stays within 2–5 g, on a practitioner's prescription, never as a course, and never self-directed. It is contraindicated in pregnancy, in loose stools, in intestinal obstruction or acute abdominal pain, in the weak and elderly, and in children.
- Topical use is short and supervised. The paste is bound in place for the time the practitioner specifies and then removed — it is not left on, and it does not go on broken skin over a wide area or on mucous membranes. Wash the hands afterwards.
- Handling and storage. Do not grind large quantities where the dust can be inhaled; label and store the seeds where they cannot be mistaken for food. Ricin is a controlled substance under chemical-weapons law in many jurisdictions in its purified form, and possession of purified ricin is a criminal matter distinct from holding the herb.
Contraindicated in pregnancy: Contraindicated in pregnancy — the seed is toxic and traditionally regarded as inducing labour or miscarriage. The classical point applications for retained placenta belong to the delivery setting and are a practitioner's decision, not a self-care measure.
For licensed practitioners’ reference only
References
- Xin Xiu Ben Cao《新修本草》(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》(the 2–5 g internal range).
4. National poisons information services publish ricin exposure guidance — a suspected ingestion is managed medically, not herbally.
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.