Fan Xie Ye
StarSenna alexandrina Mill. (syn. Cassia angustifolia Vahl; Cassia acutifolia Delile)
Traditionally used for
- Digestion
- Bowel health
- Urinary & fluids
Cautions & contraindications
- Pregnancy
- Heart conditions
- Liver conditions
- Toxic — professional use only
☯ TCM Properties
Purges Heat and Unblocks the Bowels; Moves Qi and Resolves Stagnation; Promotes Urination and Reduces Edema; Promotes Digestion and Resolves Food Stagnation
Traditional Chinese Uses
Fan Xie Ye (senna leaf) is a cold, bitter herb used as a gentle but effective laxative in Chinese medicine. It promotes bowel movements by accumulating fluid and secretions in the intestines, making it useful for acute constipation from heat and dryness. In small doses it is a mild digestive stimulant; in larger doses it is a significant cathartic. Its cold nature specifically targets heat-type constipation, and it is contraindicated in pregnancy and in those with cold-type digestive weakness.
Western Herbalism Properties
Relationships
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Botanical Description
Senna alexandrina Mill. (syn. Cassia senna; Fabaceae) is a small, erect, much-branched shrub 0.5-2 m tall with pale-green, finely pubescent young stems. The alternate, paripinnate leaves bear four to seven pairs of opposite, lanceolate, mucronate leaflets 2-5 cm long with entire margins. Axillary racemes of bright-yellow, slightly zygomorphic, five-petaled flowers produce flat, oblong, papery pods 4-7 cm long containing six to ten obovate seeds. Native to the arid lands of the Nile Valley and the Arabian Peninsula and cultivated in India (Tinnevelly senna), the dried leaflets (Fan Xie Ye) are rich in dianthrone glycosides (sennosides). The leaf is used in TCM, Ayurveda, and Western herbalism principally as a powerful stimulant cathartic for short-term constipation.
Active Constituents
Sennoside A and sennoside B
Dianthrone (bianthrone) glycosideConcentration: the European Pharmacopoeia requires senna leaf to contain not less than 2.5% total hydroxyanthracene glycosides expressed as sennoside B on the dried drug; standardised extracts are specified at 5.0-8.0%
The sennosides are the laxative principles and the basis of pharmacopoeial standardisation. They are pro-drugs: intact sennosides are poorly absorbed in the small intestine and pass to the colon, where bacterial reduction liberates the active aglycone. This is why senna acts after a delay of roughly 6-12 hours and why the response is variable between individuals with different gut flora.
Sennoside C and sennoside D
Dianthrone glycoside (heterodianthrones of rhein and aloe-emodin)Minor dianthrones accompanying sennosides A and B, contributing to the total hydroxyanthracene content on which the drug is assayed and to its laxative activity.
Rhein anthrone
Anthranoid aglyconeThe actual active species, produced in the colon by bacterial cleavage and reduction of the sennosides. It stimulates colonic propulsive motility and inhibits absorption of water and electrolytes from the lumen while promoting their secretion, which is what makes senna a stimulant rather than an osmotic laxative and what drives the potassium loss seen with chronic use.
Rhein 8-glucoside and aloe-emodin glycosides
Anthraquinone glycosideMonomeric anthranoid glycosides present alongside the dianthrones. They contribute to the total hydroxyanthracene derivative load, which is the fraction the EFSA safety assessment identified as raising genotoxicity concerns.
Tinnevellin glucoside and 6-hydroxymusizin glucoside
Naphthalene glycosideChemotaxonomic markers rather than active constituents: tinnevellin glucoside characterises Tinnevelly senna (the Cassia angustifolia entity) while 6-hydroxymusizin glucoside characterises Alexandrian senna. They are how a laboratory tells the two commercial sennas of this one species apart.
Mucilage and kaempferol glycosides
Polysaccharide and flavonol glycosideNon-anthranoid constituents of the leaf; the mucilage moderates the harshness of the crude leaf slightly but has no significant laxative action of its own.
⚠ Drug Interactions
Digoxin and other cardiac glycosides
This is the best-evidenced interaction of the anthranoid laxatives. Sennosides cause potassium loss directly in the faeces and secondarily through the renal response to sodium loss. Hypokalaemia increases the inhibitory effect of cardiac glycosides on the Na+/K+ pump, so digoxin becomes more toxic at an unchanged serum level. A population-based nested case-control study in heart failure patients found a significantly increased risk of digoxin toxicity when sennosides had been dispensed in the 14 days before the index date.
Clinical note: Avoid regular senna in patients on digoxin. If a laxative is unavoidable, prefer an osmotic agent, keep the course short, and check serum potassium.
Thiazide and loop diuretics, corticosteroids, and liquorice root (Gan Cao)
Each of these depletes potassium by its own route, and senna adds faecal potassium loss on top. The combination with liquorice is a particular trap in herbal practice, because Gan Cao appears in a very large proportion of Chinese formulas and its glycyrrhizin causes mineralocorticoid-like potassium wasting.
Clinical note: Do not combine senna with these agents for more than a few days, and check potassium if you must. Review the whole formula for Gan Cao before adding Fan Xie Ye.
Class III antiarrhythmics and other QT-prolonging drugs (amiodarone, sotalol, methadone, some antipsychotics)
Hypokalaemia from chronic anthranoid laxative use prolongs cardiac repolarisation and is a recognised precipitant of torsades in patients taking QT-prolonging drugs. The interaction is with the electrolyte disturbance rather than with the sennosides directly.
Clinical note: Avoid prolonged senna use in patients on QT-prolonging medication; if diarrhoea occurs, check potassium and magnesium.
Orally administered drugs generally, including oral contraceptives and narrow-therapeutic-index drugs
Accelerated colonic transit and reduced intestinal residence time can reduce absorption of concurrent oral medication, particularly modified-release preparations and drugs absorbed distally. The effect is proportional to the degree of purgation.
Clinical note: Separate senna from critical oral medication in time, and warn patients on oral contraceptives that a strongly purgative dose may reduce reliability.
Prolonged self-medication (laxative dependence and melanosis coli)
Stimulant anthranoid laxatives taken chronically lead to escalating doses for the same effect and to a rebound of constipation on withdrawal. Chronic use also causes melanosis coli, the benign brown pigmentation of the colonic mucosa from lipofuscin-laden macrophages, which is a marker of anthranoid exposure at colonoscopy. The WHO position and the European regulatory position are the same: senna is for occasional short-term constipation, and is generally not to be taken for more than about one to two weeks without medical advice. The EFSA panel additionally could not establish a safe daily intake of hydroxyanthracene derivatives in food because of genotoxicity concerns for the class.
Clinical note: Prescribe for short courses only, put a stop date on it, and ask about existing laxative use before adding it. Investigate rather than escalate when a patient needs increasing doses.
Other hepatotoxic drugs and herbs
Severe hepatotoxicity from senna is unusual but documented: a published case describes acute liver failure with renal impairment in a woman who drank a litre daily of tea made from 70 g of senna fruit for over three years, attributed to hepatic exposure to unusual quantities of anthranoid metabolites. Whether this compounds the risk of other hepatotoxins is not established, but the case defines the dose range at which liver injury becomes conceivable.
Clinical note: Ask about laxative abuse in any unexplained hepatitis. Do not use senna long-term in patients with existing liver disease or on hepatotoxic drugs.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction (added late) | 2–6 g | Daily | — | — | 中国药典 2020 【用法与用量】2～6g，后下，或开水泡服。 【注意】孕妇慎用。 【性味与归经】甘、苦，寒。归大肠经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Evidence Tier
Moderate evidence · 3 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
2
2 verified · 0 unverified
Other clinical trial
0
Observational / case report
1
0 verified · 1 unverified
In vitro / animal
0
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Senna Versus Magnesium Oxide for the Treatment of Chronic Constipation: A Randomized, Placebo-Controlled Trial
A double-blind, placebo-controlled randomised trial comparing senna 1.0 g, magnesium oxide 1.5 g and placebo over 28 days in chronic constipation. Overall improvement was 69.2% with senna and 68.3% with magnesium oxide against 11.7% with placebo (P less than 0.0001). Senna is genuinely effective; the trial also shows that an osmotic agent matched it, which matters when choosing a laxative for a patient in whom senna's electrolyte effects are a problem.
Effectiveness of senna vs polyethylene glycol as laxative therapy in children with constipation related to anorectal malformation
Randomised comparison of senna against polyethylene glycol in children with constipation following repair of anorectal malformation, in whom stimulant laxatives are used deliberately to produce a daily bowel action. Reports outcomes for continence and stool frequency in this specific surgical population; not generalisable to ordinary functional constipation.
Exposure to Sennoside–Digoxin Interaction and Risk of Digoxin Toxicity: A Population-Based Nested Case–Control Study
Population-based nested case-control study in heart failure patients taking digoxin. Sennoside exposure in the 14 days before the index date was associated with a significantly increased risk of hospitalisation for digoxin toxicity, with the effect attributed to sennoside-induced hypokalaemia potentiating glycoside binding to the Na+/K+ pump. This is the strongest human evidence for the anthranoid-cardiac glycoside interaction.
⚠ Rule-Based Cautions
These entries come from the deterministic rule tables that gate Verscienta's formula tools — classical pair prohibitions, pregnancy and lactation contraindications, and dose ceilings.
Breastfeeding
Avoid stimulant laxative passes into milk
Continuous use
Not beyond 7 days at a time — “Not to be used for more than 1 week.”
Adolescents over 12, adults and elderly; contraindicated under 12 (EMA). Source: EMA/HMPC/625849/2015 — European Union herbal monograph on Senna alexandrina Mill. (Cassia senna L.; Cassia angustifolia Vahl), folium (Final – first revision, 25 September 2018), §4.2 Duration of use. §4.4: use for more than a brief period of treatment may lead to impaired function of the intestine and dependence on laxatives.
A patient's own days on this herb are counted on their patient page (practitioners only).
Historical Texts
Yin Pian Xin Can (New Reference of Cut Crude Herbs), Wang Yiren
Republican China (1935)Al-Qanun fi al-Tibb (Canon of Medicine), Ibn Sina
Medieval Islamic, c. 1025 CEReferences
- EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS); Younes M, Aggett P, Aguilar F, Crebelli R, Filipič M, Frutos MJ, Galtier P, Gott D, Gundert-Remy U, Kuhnle GG, Lambré C, et al.. Safety of hydroxyanthracene derivatives for use in food . EFSA Journal (2018) [DOI]
- Çiçek SS, Moreno Cardenas C, Girreser U. Determination of Total Sennosides and Sennosides A, B, and A1 in Senna Leaflets, Pods, and Tablets by Two-Dimensional qNMR . Molecules (2022) [DOI]
- Vanderperren B, Rizzo M, Angenot L, Haufroid V, Jadoul M, Hantson P. Acute Liver Failure with Renal Impairment Related to the Abuse of Senna Anthraquinone Glycosides . Annals of Pharmacotherapy (2005) [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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