Castor Seed

Traditional Use

Primary Actions

• Resolves toxicity and reduces swelling - Bi Ma Zi is classically used for boils, abscesses, swollen lymph nodes, and severe throat swelling, usually by external application rather than casual internal dosing because of its toxicity.
• Moistens the Intestines and unblocks severe dry constipation - the seed's abundant oil can move stubborn dry stool, but traditional practice strongly prefers the purified oil or very cautious supervised use because the whole seed contains ricin-bearing toxic material.
• Opens the channels and penetrates lodged obstruction - topical preparations are used for facial paralysis, numbness, stubborn headache, and localized stagnation because the seed is said to travel deeply through the network vessels.
• Historically drives downward movement strongly enough to influence labor and retained placenta - this old use is one reason the herb is absolutely contraindicated in pregnancy.

Secondary Actions

• Modern practice treats Bi Ma Zi as primarily an external-use herb or a high-caution preparation rather than a routine internal laxative.
• When internal bowel-moistening is needed, the separate purified castor-oil preparation is generally safer and more practical than the raw seed itself.

Classic Formulas

• Bi Ma Zi with Ru Xiang (蓖麻子配乳香) - traditional topical pairing for painful swellings and severe one-sided headache, combining swelling reduction with Blood-moving pain relief.
• Bi Ma Zi with Huang Lian (蓖麻子配黄连) - historical soaking or topical preparation for chronic toxic skin disease and severe inflammatory lesions where toxin and channel obstruction coexist.
• Historical navel, sole, or lower-abdomen applications of crushed castor seed - folk-classical obstetric methods used to hasten labor or expel retained placenta, now mainly cited as a safety warning rather than a self-care recommendation.

Classical References

• Me and Qi places Bi Ma Zi in the heat-clearing and toxin-relieving category and emphasizes swelling reduction, toxic-lesion use, bowel moistening, and strong external applications.
• Traditional comparisons distinguish Bi Ma Zi from Ba Dou and Huo Ma Ren: it is less violently purgative than Ba Dou but far more toxic than Huo Ma Ren, and its main modern relevance is external rather than internal.
• PREPARATION NOTE: this raw-seed record should not be confused with Bi Ma You (castor oil), the purified oil preparation in herb #196; the raw seeds retain ricin and related toxic constituents that make them substantially riskier.