Ma Zi Ren Wan (麻子仁丸) — Hemp Seed Pill
On this page
Overview
Ma Zi Ren Wan — Hemp Seed Pill — is the classical Chinese herbal formula for constipation[11] 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, 2-15g)
nourishes Yin and Blood, moistens the intestines
Xing Ren (Prunus armeniaca seed, 2-10g)
descends Lung Qi, moistens the intestines and relieves constipation
Da Huang (Rheum palmatum root, 4-10g)
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, 2-10g)
moves Qi, descends Rebellious Qi and relieves distension
Formula actions
- Moistens the Intestines
- Unblocks the bowels
- Drains Heat
- Promotes urination
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.
Cautions
Always consult a qualified Chinese herbalist registered with the Register of Chinese Herbal Medicine (RCHM). Online herbal consultations are available. See the prices page for costs.
Prefer to be treated from home? Chinese herbal medicine online consultations are available throughout the UK and worldwide. After a full video consultation, Dr (TCM) Attilio D'Alberto formulates a bespoke herbal prescription and posts your Chinese herbs directly to your door.
References
[11] Lyu Z, Fan Y, Bai Y, Liu T, Zhong LL, Liang HF. Outcome of the efficacy of Chinese herbal medicine for functional constipation: A systematic review and meta-analysis. World J Clin Cases. 2022 May 26;10(15):4856-4877. https://doi.org/10.12998/wjcc.v10.i15.4856. PMID: 35801027.
How does Ma Zi Ren Wan work?
Ma Zi Ren Wan combines moistening, downward-draining and Qi-regulating herbs to address the heat-and-dryness pattern that underlies many chronic constipation presentations. The principal herb Huo Ma Ren (hemp seed) provides oily lubrication to soften stool; Da Huang (rhubarb root) provides moderate purgative action; Hou Po and Zhi Shi regulate Qi downward; Xing Ren and Bai Shao nourish Yin and Blood. The formula softens stool consistency and supports normal bowel motility without the harsh stimulant action of senna or bisacodyl. In TCM clinical practice it is the most widely prescribed Chinese herbal formula for chronic heat-pattern constipation and may help patients reduce or come off long-term stimulant laxative use.
Dosage and forms
- Pharmaceutical-grade granules — 4–6 g/day in 2–3 divided doses, taken with warm water; typically morning and evening. The most individualised form. Typical course 4–8 weeks.
- Patent pills — the traditional honey-bound pill form, taken 3–6 g three times daily. Convenient maintenance form once symptoms have stabilised.
I prescribe pharmaceutical-grade granules from Sun Ten in Taiwan, individualised within a bespoke prescription.
Cautions and contraindications
- Pregnancy — not used in pregnancy because of the Da Huang content (Blood-moving and uterine-stimulating)
- Cold-pattern constipation — the formula is cooling; use a warming formula like Ji Chuan Jian for cold-pattern slow-transit constipation
- Loose stools or diarrhoea — contraindicated; the formula loosens stool further
- Concurrent stimulant laxatives — safe but the combination is rarely needed; the goal is usually to reduce stimulant laxative dependence
- Long-term high-dose use — reassess after 2-3 months; chronic constipation needs underlying pattern resolution, not just symptomatic laxative effect
Always consult a qualified Chinese herbalist registered with the Register of Chinese Herbal Medicine (RCHM).
Online Chinese herbal consultations
I prescribe Chinese herbal medicine through online video consultations for patients throughout the UK and internationally. After a full case-history consultation reviewing your TCM pattern, presenting complaint, current medications and individual constitution, a bespoke prescription is formulated and the pharmaceutical-grade granules from Sun Ten in Taiwan are posted directly to your door. I am a member of the British Acupuncture Council (BAcC) and the Register of Chinese Herbal Medicine (RCHM) with over 25 years of clinical experience.
Treatment runs alongside (not instead of) conventional medical care. Always continue to be seen by your GP or specialist for any diagnosed condition; herbal medicine is used as a complementary therapy. See the prices page for consultation and dispensing fees.
Comparison with related formulas
- Run Chang Wan — gentler moistening formula for Blood-deficient dryness constipation. Use in elderly patients and post-natal recovery.
- Zeng Ye Tang — Yin-and-fluid replenishing formula for severe dryness constipation, particularly post-febrile illness.
- Ji Chuan Jian — warming Yang-tonifying formula for cold-pattern constipation in elderly Yang-deficient patients.
- Da Cheng Qi Tang — strong purgative for acute Yangming Heat constipation; not for chronic use.
Frequently asked questions
How quickly does Ma Zi Ren Wan work?
Most patients notice softer stool consistency within 3–7 days of starting the formula. Normal daily bowel function typically establishes within 2–4 weeks of consistent use. The formula works by moistening and gently moving stool rather than by mechanical purgation; it is gentler than senna or bisacodyl but more effective long-term for the underlying heat-and-dryness pattern.
Can Ma Zi Ren Wan replace senna or bisacodyl?
For chronic heat-pattern constipation it often can. Many patients use it to gradually reduce or eliminate long-term stimulant laxative dependence, which over years can desensitise bowel motility. The transition is typically gradual; reduce stimulant laxative dose week-by-week as the formula takes effect. Acute constipation flares may still need brief stimulant laxative use; the formula is primarily for chronic baseline management.
Is Ma Zi Ren Wan safe long-term?
For appropriate heat-pattern constipation, yes — the formula has been used for centuries in long-term courses. However, chronic constipation usually has an underlying TCM pattern that should be addressed for sustained resolution. After 2–3 months of good response, a reassessment is recommended; many patients move to a maintenance dose or alternate the formula with a pattern-supporting formula targeting their constitutional weakness.
Can children take Ma Zi Ren Wan?
Yes — the formula is generally well-tolerated in children with heat-pattern constipation, at age-adjusted doses (typically 30–50% of the adult dose, depending on age and weight). Always seek qualified herbalist supervision for paediatric prescribing; some children need specifically paediatric formulas rather than adult formulas dose-adjusted.
What dietary changes complement the formula?
Increase: water intake (1.5–2 L/day taken room-temperature, not iced), soluble fibre (oats, pears, prunes, kiwi fruit), vegetable variety, healthy fats (olive oil, nuts), regular daily meals with adequate volume. Reduce: ultra-processed food, excess red meat, white bread, and excessive milk/cheese in adults with sensitivity. A warm cooked breakfast within 30 minutes of waking activates the gastrocolic reflex and supports morning bowel evacuation.
Prefer to be treated from home? Chinese herbal medicine online consultations are available throughout the UK and worldwide.
