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Bai zhu

Atractylodes macrocephala

Also calledBái zhú / 白术 (Chinese) · Baizhu

In older monographsAtractylodis Macrocephalae Rhizoma (drug name)

The rhizome of a thistle-like plant of central China and one of the core 'spleen-strengthening' herbs of Chinese medicine, a member of the four-herb formula Si jun zi tang with ginseng, poria and liquorice. It is used for poor appetite, bloating and loose stools. Research is almost entirely in animals and cells; the human trials test multi-herb formulas, so bai zhu's own contribution is unknown.

What it is used for

Constipation
Limited
Water and polysaccharide extracts increased stool output and gut motility in rat and mouse constipation models. Human evidence was not found.^2,4
Cancer: drugs and supportive care
Limited
A 2024 meta-analysis of Chinese trials found that bai zhu-containing herbal formulas added to neoadjuvant chemotherapy for advanced gastric cancer were linked to better tumour response and quality of life and fewer side effects; the trials tested whole formulas and the authors called for more research.⁶
Diarrhoea
Traditional
Prescribed in Chinese medicine to 'strengthen the spleen' and 'dry dampness', for loose stools, abdominal distension and poor appetite. Its polysaccharides and bran-fried extracts reduced diarrhoea in rat and mouse models; no trials of the herb alone in people were found.^2,3
Poor appetite
Traditional
Poor appetite from 'spleen deficiency' is a classic Chinese-medicine indication, usually in formulas such as Si jun zi tang.^2,5
Wind, bloating and colic
Traditional
Abdominal distension is among its traditional gastrointestinal indications; lab studies suggest effects on gut motility and microbiota.^2,3
Breast-milk supply
Traditional
Used in Chinese herbal mixtures given to increase milk and for mastitis; because it is always mixed with other herbs, its own effect cannot be judged (LactMed).⁷

How it is prepared

decoction

The dried, sliced rhizome, often bran-fried (a Chinese Pharmacopoeia processing method that lowers the volatile oil and turns atractylon into atractylenolides), decocted with other herbs in formulas such as Si jun zi tang or Shen ling bai zhu san.

Diarrhoea · Poor appetite

Amounts are as recorded by the named source, not a recommendation.

Safety

Pregnancy: Insufficient data
Breastfeeding: Insufficient data
Children: No paediatric safety data found.

Do not use if

Chinese medicine: avoid in internal heat with yin deficiency and profuse sweating, because of the herb's 'drying' nature

Side effects

Human safety data are limited; multi-herb formulas containing Atractylodes have been well tolerated in trials of up to 8 weeks

Toxicity

Mice given very large doses of a water extract (up to 100 g/kg by injection) showed no toxic effects, and rats given the volatile oil for 90 days showed no tissue damage. A 2026 review of the genus flags atractyloside, which it lists among Atractylodes constituents, as having caused fatal kidney and liver necrosis in humans and livestock, and atractylodin as embryotoxic in zebrafish; how much reaches people from medicinal bai zhu is not established. Breastfeeding safety is unknown (LactMed).

In the healing traditions

Traditional Chinese Medicine
Bai zhu (Atractylodis Macrocephalae Rhizoma)
Strengthens the spleen and eliminates dampness; distinguished from cang zhu (A. lancea) by also arresting sweating and 'calming the fetus'. Shennong's Herbal Classic recorded 'zhu' as a top-grade drug without separating species; Tao Hongjing (AD 502–557) first described bai zhu, with large leaves and sweet rhizomes suited to pills and powders. Often bran-fried before use.
Shennong Bencao Jing; Tao Hongjing, Bencao Jing Jizhu; Chinese Pharmacopoeia (2020)
Korean medicine
Atractylodes macrocephala in Bojanggunbi-tang
A key herb of Bojanggunbi-tang, a Korean prescription for gastritis, colitis, inflammatory bowel disease, indigestion and diarrhoea, given to over 310,000 patients at one Korean medical centre between 1994 and 2010.

Active compounds

atractylenolides I–III: sesquiterpene lactones; increased by bran-frying; anti-inflammatory in lab studies
atractylon: volatile sesquiterpene linked in TCM to the herb's 'dryness'; reduced by processing
polysaccharides: fermented by gut bacteria to short-chain fatty acids in animal studies

History

The Shennong Bencao Jing (Eastern Han, AD 25–220) listed 'zhu' as a top-grade drug. Tao Hongjing split it into chizhu (later cang zhu) and bai zhu in the early 6th century, and the Song-dynasty Bencao Yanyi first separated their clinical uses, a distinction kept in the modern Chinese Pharmacopoeia.

Sources

Reference, not prescription. Nothing here is medical advice. Herbs can interact with medicines and be dangerous in pregnancy; tell your doctor or pharmacist about anything you take.