Ma Zi Ren Wan — Hemp Seed Pill

Overview

Ma Zi Ren Wan — Hemp Seed Pill — is the classical Chinese herbal formula for constipation arising from dryness and deficiency of fluids in the intestines combined with Stomach Heat that dries the bowel contents. Originating from Zhang Zhongjing’s Shang Han Lun, it achieves its laxative effect primarily by moistening and lubricating the intestines rather than by strongly draining downward, making it gentler and more suitable for prolonged use in appropriate patients.

TCM pattern

Prescribed for intestinal dryness with Stomach Heat and Spleen constraint, characterised by: dry, hard stools that are difficult to pass, frequent urination (intestinal fluids being redirected to the urine rather than lubricating the bowels), dry mouth and throat, a dry tongue with little moisture, and a floating, choppy pulse in the right guan position.

Key herbs

Ma Zi Ren (Cannabis sativa seed) — the principal herb; richly moistens and lubricates the intestines
Bai Shao (Paeonia lactiflora root) — nourishes Yin and Blood, moistens the intestines
Xing Ren (Prunus armeniaca seed) — descends Lung Qi, moistens the intestines and relieves constipation
Da Huang (Rheum palmatum root) — drains Heat and clears accumulation from the intestines in a small dose
Zhi Ke (Citrus aurantium fruit) — descends Qi and relieves abdominal distension
Hou Po (Magnolia officinalis bark) — moves Qi, descends Rebellious Qi and relieves distension

Conditions treated

Constipation in the elderly with dry, hard stools from intestinal fluid depletion — the most common clinical use
Post-illness constipation after febrile illness that has depleted body fluids
Post-partum constipation from Blood loss and fluid depletion
Chronic constipation with dry stools in patients with Yin deficiency
Haemorrhoids associated with dry, difficult-to-pass stools causing straining

Contraindicated in pregnancy and in Cold constipation from Yang deficiency.