In Traditional Chinese Medicine, constipation is not one problem — it is at least seven different patterns, each with its own cause and its own formula. The one most people picture is heat-type constipation (热秘): dry, hard stools that come with a feeling of internal heat, a dry mouth, and bad breath. Its classical answer is Ma Zi Ren Wan (麻子仁丸), a formula that has been in continuous use since the Eastern Han dynasty, nearly two thousand years ago.
- TCM treats constipation by pattern, not symptom — the textbook lists seven distinct types.
- Heat-type constipation (热秘) is dry, hard stools plus heat signs: dry mouth, bad breath, flushed face.
- Ma Zi Ren Wan (麻子仁丸) is its classical formula, first recorded in the Shang Han Lun (~200 CE).
- Ma Zi Ren Wan is sold in the West as a herbal supplement — used traditionally, not as a treatment for a diagnosed disorder.
🧪 What the Science Says
Modern research has begun to echo what the classical texts described. A 2026 systematic review and network meta-analysis in Nutrition Reviews (PMID 41217200) evaluated functional foods for irritable bowel syndrome with constipation, finding that natural fruits — kiwi and fig — ranked first for both relieving abdominal pain and improving quality of life, outperforming isolated dietary fiber. That finding aligns with TCM's preference for moistening, gentle-laxative whole foods over harsh, isolated laxatives.
A separate 2025 systematic review in Medicine (Baltimore) (PMID 40295286) examined the TCM "clearing heat and laxative" method (清热通下法) — the same therapeutic principle behind heat-constipation formulas — and found it was associated with improvements in several metabolic markers. As with all of these studies, the framing is supportive — "associated with," "may support" — not proof of a cure.
Constipation in TCM: Seven Patterns, Not One
The textbook Chinese Internal Medicine (中医内科学) divides constipation (bian mi, 便秘) into seven patterns. Heat-type constipation is the most common of the three "excess" (实秘) patterns; the other four are "deficiency" (虚秘) patterns:
| Pattern (证型) | Typical signs | Classical formula |
|---|---|---|
| Heat type (热秘) | Dry, hard stools; dry mouth, bad breath, flushed face, scanty dark urine | Ma Zi Ren Wan (麻子仁丸) |
| Qi stagnation (气秘) | Difficulty passing stool, belching, abdominal distension relieved by passing gas | Liu Mo Tang (六磨汤) |
| Cold type (冷秘) | Constipation with cold limbs, pale face, abdominal pain relieved by warmth | Wen Pi Tang + Ban Liu Wan (温脾汤合半硫丸) |
| Qi deficiency (气虚秘) | Urge to go but weak straining, fatigue, shortness of breath | Huang Qi Tang (黄芪汤) |
| Blood deficiency (血虚秘) | Dry stool, pale dull complexion, dizziness, palpitations | Run Chang Wan (润肠丸) |
| Yin deficiency (阴虚秘) | Dry, pellet-like stools, dry mouth and throat, night sweats, warm palms | Zeng Ye Tang (增液汤) |
| Yang deficiency (阳虚秘) | Difficult defecation, feeling of cold, sore low back, frequent urination | Ji Chuan Jian (济川煎) |
The reason the pattern matters is that the wrong formula does nothing useful — and can make things worse. A person with a cold-type or deficiency constipation given a heat-draining formula would be further drained, not helped. Pattern differentiation is the whole game.
Recognizing Heat-Type Constipation
This pattern is classically described as the constipation of accumulated heat. In TCM, the stomach and intestines are said to be the organs that "descend" — they should move food and waste downward. When heat builds up there, it gradually consumes the fluids that keep the stool moist, so the stool dries out, hardens, and becomes difficult to pass.
The typical picture includes:
- Dry, hard stools that are difficult or painful to pass
- A dry mouth and bad breath
- A flushed face and a subjective feeling of warmth
- Scanty, dark urine
- Abdominal fullness or discomfort
- In TCM diagnosis: a red tongue with a dry yellow coating, and a slippery rapid pulse
The treatment principle is summed up in two four-character phrases: xie re dao zhi (泻热导滞), "drain heat and guide out stagnation," paired with run chang tong bian (润肠通便), "moisten the intestines to promote bowel movement."
Ma Zi Ren Wan: The Hemp Seed Pill
Ma Zi Ren Wan (麻子仁丸, "Hemp Seed Pill"; also written 麻仁丸) is the formula named for this pattern. It was first recorded in Zhang Zhongjing's Shang Han Lun (伤寒论, "Treatise on Cold Damage Disorders"), compiled around 200 CE — one of the foundational texts of the Chinese medical canon, and the same source as many of TCM's most famous formulas.
"趺阳脉浮而涩，浮则胃气强，涩则小便数，浮涩相搏，大便则硬，其脾为约，麻子仁丸主之。"
"The fu yang pulse is floating and rough — floating indicates stomach qi is strong, rough indicates frequent urination; when floating and rough contend, the stool becomes hard. This is called spleen constraint (脾约), and Ma Zi Ren Wan governs it." — Shang Han Lun, ~200 CE
The classical term for this pattern is pi yue (脾约, "spleen constraint"): the stomach has too much heat and the spleen's function is constrained, so the body diverts fluids away from the stool and toward the urine, leaving the stool hard. In modern textbooks this same formula is classified under heat-type constipation.
The formula is a compact combination of moistening and downward-moving herbs. Its defining ingredient is ma zi ren (hemp seed, 麻子仁), a naturally oily seed that moistens the intestines; it is supported by xing ren (apricot kernel, 杏仁) and shao yao (peony root, 芍药), which also moisten and soften. A small amount of da huang (rhubarb root, 大黄) gently drains heat and moves the bowels, aided by zhi shi (immature bitter orange, 枳实) and hou po (magnolia bark, 厚朴) to guide qi downward. The whole is formed into pills with honey.
⚠️ Safety Note
Ma Zi Ren Wan is a herbal supplement, not a medicine, and this article is educational — not medical advice and not a treatment for any condition. It is not a substitute for evaluating or treating a diagnosed bowel disorder with a qualified professional.
This formula contains rhubarb root (da huang), a stimulant laxative. For that reason it is meant for short-term, occasional use, not long-term daily use, and is generally avoided during pregnancy. If you are pregnant, nursing, taking medication, or managing a chronic or digestive condition, talk to your healthcare provider before use. Follow the product's own suggested use on its label rather than any dose mentioned elsewhere.
A note on cinnabar: some classical formulas — notably Zhu Sha An Shen Wan (朱砂安神丸) — contain the mineral cinnabar (mercury sulfide), which has been the subject of safety warnings and should be avoided. Ma Zi Ren Wan does not contain cinnabar. Read our full disclaimer.
Ma Zi Ren Wan as a Supplement
In the West, Ma Zi Ren Wan is widely available as a herbal supplement in capsule or granule form, from established suppliers of traditional formulas. Because it has been made for centuries and is one of the most recognizable classical formulas, there are many brands — which also means quality and formulation vary, so it is worth choosing a supplier you trust.
🛒 Ma Zi Ren Wan (Hemp Seed Pill) — a well-established option
$37.80
Treasure of the East · Apricot Kernel Formula · 100 vegetarian capsules
A traditional ma zi ren wan capsule formulation, sold as a herbal supplement. Always follow the label's suggested use, and check with a healthcare provider if you take medication or have a medical condition.
View on Chinese Herbs Direct →Disclosure: This is an affiliate link. If you click and make a purchase, Tcmplate may earn a commission at no extra cost to you. This does not influence which formulas are recommended — selections are based on classical TCM sources and pattern differentiation, not commission rates.
Other established brands also offer Ma Zi Ren Wan, including Plum Flower and Bio Essence Health Science — useful if you prefer a particular supplier or a different format (capsules or granules). The Bio Essence line, for example, lists its version at a lower price point, and Plum Flower offers a classic 200-count teapill option.
Frequently Asked Questions
What is Ma Zi Ren Wan (麻子仁丸)?
Ma Zi Ren Wan ("Hemp Seed Pill"; also written 麻仁丸) is a classical Chinese herbal formula, first recorded in Zhang Zhongjing's Shang Han Lun (~200 CE). It is traditionally used in Chinese medicine to drain heat, moisten the intestines, and promote bowel movement in the heat-constipation pattern. It is sold in the West as a herbal supplement, not a drug.
What is heat-type constipation (热秘) in TCM?
Heat-type constipation (热秘) is a pattern in which accumulated heat in the stomach and intestines consumes the body's fluids, drying and hardening the stool. The classical picture is dry, hard stools that are difficult to pass, together with heat signs such as dry mouth, bad breath, a flushed face, a feeling of warmth, and scanty dark urine. The treatment principle is to drain heat and moisten the intestines to restore regular bowel movement.
Is Ma Zi Ren Wan safe to take?
Ma Zi Ren Wan is generally sold as a herbal supplement and should be used according to the label's suggested use. Because it contains rhubarb root — a stimulant laxative — it is meant for short-term use, not long-term daily use, and is generally avoided during pregnancy. Consult a qualified healthcare provider if you are pregnant, nursing, taking medication, or managing a chronic or digestive condition. It is not a substitute for treating a diagnosed bowel disorder, and unlike some other classical formulas it does not contain cinnabar (mercury sulfide).
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