Chinese Rhubarb
PolygonaceaeRheum palmatum
Also known as: Da Huang, Turkey Rhubarb, Medicinal Rhubarb
clinical_notes Clinical Summary
Chinese Rhubarb (Rheum palmatum, Da Huang) is a classic purgative and blood-mover used in both Chinese medicine and Western pharmacopoeia.
At low doses it acts as a bitter astringent and digestive tonic; at higher doses its anthraquinones (sennosides, rhein, emodin) stimulate colonic peristalsis and drain 'heat accumulation.' Use is limited to short courses — ideally under 1-2 weeks — and contraindicated in pregnancy, lactation, intestinal obstruction, and chronic constipation from atonic or inflammatory causes.
Pregnancy Safety
Contraindicated due to pelvic-congesting and uterine-stimulant activity of stimulant anthraquinones.
Lactation Safety
Avoid; small amounts of anthraquinone metabolites may pass to milk and cause infant diarrhea.
warning Contraindications
- Pregnancy (contraindicated)Theoretical
- Lactation (avoid)Theoretical
- Children <12 y (contraindicated)Theoretical
- Intestinal obstruction / ileus / undiagnosed acute abdomen (contraindicated)Theoretical
- Inflammatory bowel disease (Crohn's, UC) (avoid)Theoretical
- Chronic stimulant-laxative use (>1-2 weeks) (caution)Clinically Proven
- History of kidney stones / hyperoxaluria (caution)Theoretical
- Concurrent digoxin, loop/thiazide diuretics, or corticosteroids (caution)Clinically Proven
vital_signs Clinical Profile
Primary Indications
- check_circle Acute constipation with heat
- check_circle Impacted bowel with abdominal distention
- check_circle Acute appendicitis (as adjunct)
- check_circle Cholestasis / jaundice
- check_circle Upper GI bleeding (charred form)
- check_circle Amenorrhea from Blood stasis
- check_circle Burns (topical)
Therapeutic Actions
System Affinities
- check_circle gastrointestinal tract
- check_circle hepatobiliary system
- check_circle blood
labs Active Constituents
Anthraquinone glycosides
Tannins
Stilbenes
Resins
Calcium oxalate crystals
history_edu Traditional Use
Traditional Chinese Medicine (TCM)
大黄 (Dà Huáng)
Nature: cold
- Heat accumulation with constipation
- Damp-Heat jaundice
- Blood stasis (amenorrhea, fixed masses)
- Fire toxin with sores
- Blood heat hemorrhage (charred form)
- Yangming organ pattern (high fever, constipation, delirium)
Processed forms differ: raw Da Huang is strongest purgative; wine-fried moves upward/blood; charred Da Huang (Da Huang Tan) is hemostatic. Cornerstone of Zhang Zhongjing's Yangming purgative strategy.
Traditional Uses Across Healing Systems
While many herbs lack controlled clinical trials, centuries of traditional practice across cultures provide valuable insight into their therapeutic applications.
Purges Heat and accumulation, drains Fire, cools Blood, invigorates Blood, expels Blood stasis, clears Damp-Heat.
One of the 'fifty fundamental herbs' in TCM.
Used as bitter digestive tonic at low dose; as stimulant laxative for constipation at higher dose.
Turkey Rhubarb was historically a major trade commodity, more valuable than gold at times.
Classified as hot-dry; used to purge 'burnt' humors and for jaundice.
Called 'Rawand Chini' in Unani pharmacopoeia.
spa Parts Used
root and rhizome
- Constipation
- Heat accumulation
- Jaundice
- Upper GI bleeding (charred)
Harvested in autumn from plants 3-5 years old. Sliced and dried. Processed forms: raw (strongest purgative), wine-fried (moves blood), charred (hemostatic), and steamed (gentler).
shield Safety
Contraindications — Evidence Basis
Pregnancy
Stimulant anthraquinones cause pelvic congestion and may stimulate the uterus.
Lactation
Anthraquinone metabolites may transfer to milk and cause infant diarrhea.
Children <12 y
EMA: not recommended under 12 due to laxative risks.
Intestinal obstruction / ileus / undiagnosed acute abdomen
Stimulant laxatives contraindicated in obstruction.
Inflammatory bowel disease (Crohn's, UC)
Stimulant action may exacerbate mucosal inflammation.
Chronic stimulant-laxative use (>1-2 weeks)
Associated with electrolyte depletion (hypokalemia), melanosis coli, and laxative dependence.
History of kidney stones / hyperoxaluria
High oxalate content may aggravate oxalate stone risk.
Concurrent digoxin, loop/thiazide diuretics, or corticosteroids
Hypokalemia from chronic stimulant laxatives potentiates digoxin toxicity.
Monitoring Parameters
Monitor during use, especially with prolonged or high-dose therapy.
Serum potassium
Baseline and periodically with use >1 weekChronic stimulant laxatives cause hypokalemia.
flagThreshold: K+ <3.5 mmol/L: discontinue and supplement.
Bowel frequency and stool consistency
Daily during acute useTitrate to softest stool; avoid watery diarrhea.
flagThreshold: More than 2 loose stools/day: reduce dose.
Toxicity
At >1 g/day of anthraquinone-standardized extract for extended periods, electrolyte imbalance and laxative dependence develop. Acute overdose causes severe watery diarrhea.
Abdominal cramps, severe diarrhea, dehydration, hypokalemia, muscle weakness, arrhythmia; melanosis coli with chronic use.
Discontinue; correct fluid/electrolyte imbalance; consider potassium supplementation.
Adverse Effects
CYP Metabolism
Emodin is a CYP3A4, CYP1A2 and CYP2C9 inhibitor in vitro; clinical relevance uncertain. Stimulant laxatives reduce transit time and can reduce absorption of co-administered oral drugs.
swap_horiz Interactions
Warfarin
Class: Anticoagulant (vitamin K antagonist)
Rhubarb acts as a stimulant laxative (anthraquinones rhein, emodin, aloe-emodin, chrysophanol). Diarrhea reduces vitamin K absorption and alters gut flora, increasing warfarin's anticoagulant effect. Anthraquinones also show intrinsic antiplatelet activity.
Avoid chronic rhubarb laxative use in anticoagulated patients. If used short-term, monitor INR and watch for bleeding. Discontinue if diarrhea occurs.
Digoxin
Class: Cardiac glycoside
Chronic stimulant laxative use (including rhubarb) causes potassium depletion. Hypokalemia potentiates digoxin binding to the Na+/K+-ATPase, increasing risk of digoxin toxicity (arrhythmia, nausea, visual changes) at therapeutic serum levels.
Avoid chronic rhubarb use in patients on digoxin. Check serum potassium and digoxin level within 1-2 weeks of initiation. Replace potassium if needed.
Loop and thiazide diuretics (furosemide, hydrochlorothiazide)
Class: Diuretic
Stimulant-laxative-induced GI potassium loss combined with kaliuretic diuretics can precipitate severe hypokalemia, leading to arrhythmias, muscle weakness, and metabolic alkalosis.
Avoid chronic combined use. Monitor serum potassium and magnesium regularly. Consider potassium-sparing diuretic or potassium supplementation.
Corticosteroids (prednisone, hydrocortisone)
Class: Glucocorticoid
Both anthraquinone laxatives and corticosteroids lower serum potassium. Additive hypokalemia may cause cardiac arrhythmias and muscle weakness, especially in high-dose or long-term steroid use.
Monitor electrolytes when combined. Replace potassium proactively. Prefer bulk-forming or osmotic laxative alternatives.
Cyclosporine
Class: Immunosuppressant (calcineurin inhibitor)
In rats, rhubarb significantly decreased systemic exposure (AUC) of cyclosporine, which is metabolized by CYP3A4 and effluxed by P-glycoprotein. Rhubarb modulates both pathways and its laxative action reduces absorption time.
Avoid rhubarb in transplant patients on cyclosporine. Monitor cyclosporine trough levels closely if exposure occurs; consider dose increase if levels fall.
Methotrexate
Class: Antineoplastic / Antirheumatic (antimetabolite)
In rats, rhubarb co-administration altered methotrexate pharmacokinetics, likely via anthraquinone inhibition of organic anion transporters (OAT1/OAT3) that clear methotrexate renally, elevating systemic exposure.
Avoid concurrent use in patients on methotrexate for cancer or autoimmune disease. Monitor LFTs, creatinine, and CBC; watch for mucositis and myelosuppression.
Oral medications (general)
Class: All oral drugs
Rhubarb is a stimulant laxative that reduces gastrointestinal transit time. Rapid transit can reduce absorption of orally administered medications, particularly those with slow dissolution or absorption in the small intestine.
Take oral medications at least 2 hours before or after rhubarb products. Monitor response to chronic oral therapies if rhubarb use is ongoing.
Other stimulant laxatives (senna, bisacodyl, cascara)
Class: Stimulant laxative
Additive anthraquinone/diphenylmethane laxative effects can produce severe diarrhea, dehydration, electrolyte derangement (hypokalemia, hypomagnesemia), and melanosis coli with chronic use.
Do not combine stimulant laxatives. Limit rhubarb use to short courses (< 1-2 weeks). Use osmotic or bulk-forming alternatives for chronic constipation.
hub Combinations
Synergistic pairings can enhance therapeutic outcomes, while knowing suitable substitutes helps when specific herbs are unavailable or contraindicated.
Classical Formulas
4Aconite (processed, Fu Zi)
Traditional UseClassic pairing in Da Huang Fu Zi Tang for Cold accumulation with constipation; warms while purging.
Empirical TCM use since Han dynasty.
Chinese Skullcap
Traditional UseTriad with Coptis in San Huang Xie Xin Tang for Heat with bleeding; anti-inflammatory and hemostatic synergy.
Documented use in Damp-Heat syndromes.
Goldthread
Traditional UsePair in San Huang Xie Xin Tang with Scutellaria baicalensis for heat with upper GI bleeding, agitation, and hypertension.
Used in TCM for acute hypertension and bleeding disorders.
Mirabilite (Mang Xiao)
Moderate EvidencePair in Da Cheng Qi Tang; Mirabilite softens hardness, Da Huang purges — the core purgative combination.
Used acutely in hospital TCM settings for ileus and severe constipation.
Possible Substitutes
1Senna
Strong EvidenceBoth are anthraquinone stimulant laxatives with nearly identical mechanisms; Senna is preferred in Western practice for short-term constipation.
Pharmacologically equivalent mechanism; comparative efficacy data.
science Studies
Constipation Mitigation by Rhubarb Extract in Middle-Aged Adults Is Linked to Gut Microbiome Modulation: A Double-Blind Randomized Placebo-Controlled Trial
RCTThis double-blind, placebo-controlled RCT randomized middle-aged adults (95% women, avg. 58 years) with constipation into three groups: rhubarb extract at 12.5 mg/day rhein, 25 mg/day rhein, or placebo (maltodextrin) for 30 days. Both rhubarb doses significantly improved stool frequency, consistency, and perceived transit speed compared to placebo. Rhubarb extract supplementation increased Lachnospiraceae (specifically Roseburia and Agathobacter) abundance and short-chain fatty acid (SCFA) production. Fecal Lachnospiraceae and SCFA levels correlated positively with stool consistency improvements, suggesting gut microbiome modulation underlies the laxative benefit.
Meta-Analysis of Efficacy of Rhubarb Combined With Early Enteral Nutrition for the Treatment of Severe Acute Pancreatitis
Meta-AnalysisThis meta-analysis pooled 11 randomized controlled trials comprising 724 patients with severe acute pancreatitis (SAP) to evaluate rhubarb combined with early enteral nutrition versus EEN alone. Rhubarb plus EEN significantly reduced hospital stay (MD -4.49 days), ICU stay (MD -2.82 days), abdominal pain duration (MD -2.20 days), and distension duration (MD -2.31 days) compared to EEN alone. Additionally, white blood cell counts and CRP were significantly lower in the rhubarb group. Hospitalization costs were also substantially reduced. These data strongly support rhubarb as a beneficial adjunct in SAP management.
medication Dosing
decoction
3-15 g dried root (purgative); 1-3 g (digestive bitter)
1x/day at bedtime for laxative effect
Add Da Huang in the last 5 minutes of decoction (hou xia) to preserve purgative anthraquinones; prolonged cooking destroys them.
tincture
0.5-2 mL (1:5, 60% ethanol)
1-2x/day
Low doses for bitter tonic effect; short-term only for constipation.
capsule
20-30 mg hydroxyanthracene derivatives (calculated as rhein)
1x/day at bedtime
EMA maximum; do not use longer than 1-2 weeks without medical supervision.
Disclaimer: This information is largely AI-generated and reviewed by human experts at Evara Health. It is intended for educational and clinical reference purposes only and should not replace professional medical advice.
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