Da Huang
StarRheum palmatum L., Rheum tanguticum Maxim. ex Balf., Rheum officinale Baill.
☯ TCM Properties
Purges Heat and Unblocks the Bowels; Clears Heat and Drains Fire; Cools the Blood and Resolves Toxicity; Invigorates Blood and Dispels Stasis; Clears Damp-Heat and Resolves Jaundice
Traditional Chinese Uses
Da Huang (rhubarb root and rhizome) is a cold, bitter herb with a powerful purging action on the Large Intestine, making it one of the most important laxative herbs in Chinese medicine. It evacuates heat-type constipation, drains Damp-Heat from the Stomach and Intestines for dysentery and jaundice, cools the Blood to stop bleeding and clear sores, and invigorates Blood to address stasis. Raw rhubarb has a stronger action; wine-processed rhubarb has a reduced purging action but enhanced Blood-moving properties.
Western Herbalism Properties
Used In Formulas (4)
Botanical Description
Rheum palmatum, Chinese or Turkish rhubarb, is a large perennial herbaceous plant in the family Polygonaceae, native to the cool mountainous regions of western China, Tibet, and Mongolia. It grows from a thick, branching, woody rhizome with deep yellow internal flesh and stout, fleshy roots. Basal leaves are very large, up to 90 cm across, broadly cordate, and deeply palmately lobed into 5-7 acute, pinnately cut segments borne on long, stout, reddish petioles. A robust hollow flowering stem rises 1.5-3 meters and bears a large terminal panicle of small, six-tepalled, greenish-white to deep red flowers. Fruit is a three-winged reddish-brown achene. Da Huang refers to the dried rhizome and root.
Active Constituents
Sennosides (A and B)
Dianthrone glycosidesConcentration: Principal purgative constituents
The main stimulant-laxative principles. After bacterial cleavage in the colon to rhein-anthrone, they stimulate colonic motility and inhibit water/electrolyte absorption, producing the purgative action ('purges Heat and unblocks the bowels'). Their bulk is lost with prolonged decoction, so Da Huang is added late (hou xia) when purgation is intended.
Rhein
AnthraquinoneConcentration: Major free/bound anthraquinone
A key bioactive anthraquinone with anti-inflammatory, antibacterial, lipid-regulating and antifibrotic activity; inhibits TGF-β1-driven fibrosis and is studied for renal protection in chronic kidney disease.
Emodin
AnthraquinoneConcentration: Major free/bound anthraquinone
A broadly studied anthraquinone with anti-inflammatory, immunomodulatory, antimicrobial, hepatoprotective and anticancer activity; contributes to the blood-cooling and toxicity-resolving actions.
Aloe-emodin
AnthraquinoneConcentration: Minor anthraquinone
Anthraquinone with antibacterial, antiviral and cytotoxic/anticancer activity; part of the free-anthraquinone fraction.
Chrysophanol
AnthraquinoneConcentration: Major free anthraquinone
A prominent free anthraquinone with anti-inflammatory and antimicrobial activity; a Pharmacopoeia marker for identity and assay of rhubarb.
Physcion (emodin monomethyl ether)
AnthraquinoneConcentration: Minor-to-moderate anthraquinone
Contributes to antimicrobial and antioxidant activity within the anthraquinone complex; another Pharmacopoeia identity marker.
Gallotannins / catechin
Hydrolyzable and condensed tanninsConcentration: Large non-anthraquinone fraction
Astringent polyphenols (including catechin and galloyl-glucoses) that counterbalance the purgative action; in small doses they can produce a secondary constipating/astringent and hemostatic effect and contribute antioxidant and hepatoprotective activity.
Stilbenes (e.g., rhaponticin)
Stilbene glycosidesConcentration: Minor
Antioxidant and lipid-modulating stilbene glycosides characteristic of Rheum species.
⚠ Drug Interactions
Digoxin and other cardiac glycosides
As a stimulant (anthraquinone) laxative, chronic or excessive Da Huang use can cause potassium loss; the resulting hypokalemia sensitizes the myocardium to cardiac glycosides and increases the risk of digoxin toxicity and arrhythmia. This is a well-established class effect of stimulant laxatives.
Clinical note: Avoid prolonged or high-dose use with digoxin; monitor serum potassium.
Potassium-depleting diuretics and corticosteroids
Additive potassium loss when the stimulant-laxative action of Da Huang is combined with thiazide/loop diuretics or corticosteroids, potentiating hypokalemia.
Clinical note: Monitor electrolytes with concurrent long-term use; limit duration of laxative dosing.
Oral medications (general absorption effect)
Accelerated intestinal transit from the purgative effect, and tannin binding, can reduce the absorption of some concurrently taken oral drugs.
Clinical note: Separate administration of important oral medicines from purgative doses of Da Huang.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 6-15g | Daily | — | — | — |
Preparation Methods
Raw rhubarb added late to decoction (Sheng Da Huang, hou xia)
Parts: dried root and rhizome
For strong purgation the raw herb (typical dose 3-15 g) is added in the last few minutes of decoction, because prolonged boiling destroys the sennosides and greatly weakens the laxative effect. This form most strongly purges Heat and unblocks the bowels.
Wine-processed rhubarb (Jiu Da Huang)
Parts: dried root and rhizome
Stir-processing with wine moderates the purgative action and directs the herb upward, favoring clearing of Heat in the upper body and invigorating the Blood to dispel stasis rather than draining the bowels.
Charred rhubarb (Da Huang Tan)
Parts: dried root and rhizome
Carbonizing the herb largely abolishes the purgative action and emphasizes the astringent/hemostatic effect, used to cool the Blood and stop bleeding.
Steamed rhubarb (Shu Da Huang)
Parts: dried root and rhizome
Steaming (often repeatedly with wine) gives a milder preparation with reduced purgative harshness, suitable for weaker patients where gentler clearing of Heat is desired.
Clinical Studies
Clinical effect of rhubarb on the treatment of chronic renal failure: A meta-analysis
Meta-analysis of 34 controlled trials (2,786 patients) found that rhubarb-based therapy significantly reduced serum creatinine, blood urea nitrogen and uric acid and improved creatinine clearance and overall symptom response in chronic renal failure, though it showed no significant benefit for hemoglobin; the authors cautioned that more rigorous trials are needed.
Botany, Traditional Use, Phytochemistry, Pharmacology and Clinical Applications of Rhubarb (Rhei Radix et Rhizoma): A Systematic Review
Systematic review cataloguing the anthraquinones, stilbenes, tannins and other constituents of rhubarb and summarizing purgative, anti-inflammatory, antibacterial, hepato-renal protective, hypolipidemic and antitumor pharmacology together with clinical applications and toxicology.
Historical Texts
Shennong Bencao Jing (Divine Husbandman's Classic of Materia Medica)
Han dynasty (c. 200 CE)Shanghan Lun / Jin Gui Yao Lue, Zhang Zhongjing
Eastern Han (c. 200 CE)Bencao Gangmu (Compendium of Materia Medica), Li Shizhen
Ming dynasty (1578)References
- Huang W, Rao Y, Li L, Li C, An Y. Clinical effect of rhubarb on the treatment of chronic renal failure: A meta-analysis . Frontiers in Pharmacology (2023) [DOI]
- Xu H, Wang W, Li X, Li Y, Jiang Y, Deng C, Song X, Zhang D. Botany, Traditional Use, Phytochemistry, Pharmacology and Clinical Applications of Rhubarb (Rhei Radix et Rhizoma): A Systematic Review . American Journal of Chinese Medicine (2024) [DOI]
- Chinese Pharmacopoeia Commission. Pharmacopoeia of the People's Republic of China (2020 Edition), Volume I — Da Huang (Rhei Radix et Rhizoma) . China Medical Science Press (2020) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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