Castor Oil

Traditional Use

Primary Actions

• Moistens the Intestines and relaxes the bowels - Bi Ma You is the purified oily preparation traditionally used for dry constipation, abdominal distension, and obstructed stool when lubrication and downward movement are needed.
• Moistens the skin and protects damaged tissue - topical castor oil is used for dryness, roughness, and irritated surfaces where an emollient, softening oil is preferred over harsher seed preparations.
• Supports external treatment of scabies, minor burns, and irritated skin lesions - traditional summaries place Bi Ma You among practical preparation-state medicinals that can both soften and shield inflamed tissues while reducing friction.
• Functions as the safer bowel-moving preparation derived from Bi Ma Zi - compared with the raw seed, the purified oil is the form traditionally preferred for internal laxative use because the dangerous seed proteins are removed during proper oil extraction.

Secondary Actions

• Bi Ma You is still not a food oil to use casually for long periods; it acts as a strong stimulant laxative and is best understood as a short-course medicinal preparation.
• The oil and the raw seed belong to the same plant, but their safety profiles are dramatically different: the seed is toxic because of ricin-bearing tissues, whereas properly prepared castor oil does not retain that same toxin burden.

Classical References

• TCM Wiki lists Bi Ma You as sweet, acrid, neutral, and toxic, entering the Lung and Large Intestine channels, with the actions of moistening the intestines to relax the bowels and moistening the skin.
• Traditional indication lists specifically include scabies, constipation, abdominal distension, and burns, showing the dual internal-external role of the oil preparation.
• PREPARATION NOTE: this record is for the purified seed oil, not the whole castor seed Bi Ma Zi; the latter is far more toxic and is recorded separately as herb #197.