Lu Hui
StarAloe barbadensis Mill. / Aloe ferox Mill.
Traditionally used for
- Headaches
- Dizziness
- Eye health
- Bowel health
- Mood & calm
- Skin
Cautions & contraindications
- Pregnancy
- Breastfeeding
- Young children
☯ TCM Properties
Purges Heat and Unblocks the Bowels; Clears Liver Fire; Kills parasites and treats childhood nutritional impairment
Traditional Chinese Uses
Lu Hui (aloe vera, dried aloe latex) is a cold, bitter herb that strongly purges Intestinal Heat and Fire, kills parasites, and clears Liver Fire. In Chinese medicine, it is used for severe constipation with heat signs, habitual constipation, and intestinal parasites. Its Liver-clearing action addresses headache, dizziness, irritability, and red eyes from Liver Fire. Applied externally, it cools burns, sores, and skin conditions. Its potent purgative action means it is used in small doses and avoided in debilitated patients.
Western Herbalism Properties
Relationships
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Botanical Description
Aloe is a genus of succulent perennials in Asphodelaceae; the medicinal sources Lu Hui include principally Aloe vera (L.) Burm.f. (syn. A. barbadensis) and Aloe ferox Mill. Plants form rosettes of fleshy, lance-shaped leaves with toothed margins, the inner parenchyma containing a clear mucilaginous gel and just beneath the rind a bitter yellow latex rich in anthraquinone glycosides (aloin). Tall racemes bear tubular yellow to orange-red flowers. Native to arid regions of Africa and the Arabian Peninsula and now widely cultivated, aloe yields two distinct products: the gel (used externally for burns and skin) and the dried, concentrated latex (Lu Hui), a powerful purgative used in TCM, Ayurveda, and Western herbalism to drain heat from the Liver and dispel constipation.
Active Constituents
Aloin A and aloin B (barbaloin)
Anthrone C-glycosideConcentration: the European Pharmacopoeia requires Barbados aloes to contain not less than 28% hydroxyanthracene derivatives expressed as barbaloin, and Cape aloes not less than 18%, both on the dried drug
The principal laxative constituents. Being C-glycosides they pass the small intestine largely unabsorbed and are cleaved by colonic bacteria to the active aglycone, which is why the effect appears six to twelve hours after the dose and why antibiotic-suppressed flora can blunt it. The very high assay minima are the clearest statement that the drug of Lu Hui is the dried leaf exudate, not the inner-leaf gel sold as aloe vera juice.
Aloinosides A and B
Anthrone C,O-diglycoside (11-O-alpha-L-rhamnosides of aloins A and B)Concentration: characteristic of Cape aloes (Aloe ferox); absent from Barbados aloes
An authentication marker as much as an active. Their presence identifies Cape aloes and their absence identifies Barbados aloes, so a chromatogram distinguishes the two source species that this record combines under one name. They are hydrolysed and reduced by colonic flora to the same active aglycone as aloin.
7-Hydroxyaloins A and B
Anthrone C-glycosideConcentration: characteristic of Barbados aloes (Aloe barbadensis)
Together with the 8-O-methyl-7-hydroxyaloins and their coumaroyl and cinnamoyl esters, these are the constituents that mark material as Barbados rather than Cape aloes.
5-Hydroxyaloin A
Anthrone C-glycosideConcentration: characteristic of Cape aloes (Aloe ferox)
A second Cape-aloes marker alongside the aloinosides, used in pharmacopoeial identity testing.
Aloe-emodin
Anthraquinone aglyconeConcentration: present in small quantities in both Barbados and Cape aloes
The constituent that drives the regulatory position on this drug. EFSA concluded that aloe-emodin and emodin are genotoxic in vitro and that aloe-emodin is genotoxic in vivo, and could not set a safe intake for hydroxyanthracene derivatives in food. It is also the reason use in pregnancy is not recommended even at conventional laxative doses.
Chrysophanol
Anthraquinone aglyconeConcentration: present in small quantities in both Barbados and Cape aloes
A minor free anthraquinone of the dried juice, contributing little to the laxative action relative to the anthrone glycosides.
Aloeresins (2-alkylchromones, including aloesin and aloeresin A)
ChromoneConcentration: a substantial non-anthranoid fraction of the dried juice in both source species
The main non-laxative constituents of the drug. They contribute to the intense bitterness that gave Lu Hui its Chinese folk name of elephant gall, and they are the fraction usually credited with the traditional Liver-fire-clearing and antimicrobial claims, though the evidence for those is weak.
⚠ Drug Interactions
Digoxin and other cardiac glycosides
The EMA herbal monograph on Barbados and Cape aloes states directly that hypokalaemia resulting from long-term laxative use potentiates the action of cardiac glycosides. Anthranoid catharsis causes potassium loss in stool; potassium depletion increases digoxin binding to Na,K-ATPase and lowers the arrhythmia threshold. Chronic use may additionally cause albuminuria and haematuria.
Clinical note: Do not use in a digitalised patient. Where Lu Hui has already been taken for more than a short course, check serum potassium before assuming digoxin toxicity has some other cause. Limit any use to one to two weeks; beyond that, medical supervision is required.
Diuretics, corticosteroids and Gan Cao (licorice root)
The EMA monograph names diuretics, adrenocorticosteroids and liquorice root specifically as agents whose concomitant use may enhance the electrolyte imbalance caused by aloes. Licorice causes potassium loss through pseudoaldosteronism, which is additive to laxative-induced loss. This matters particularly in Chinese practice because Gan Cao appears in a large proportion of formulas, so the combination arises easily and unintentionally.
Clinical note: Screen the whole prescription for Gan Cao before adding Lu Hui, and ask about licorice sweets and teas. In a patient on a thiazide or loop diuretic, or on prednisolone, check potassium.
Antiarrhythmics and QT-prolonging drugs (quinidine, sotalol, amiodarone, macrolides)
The EMA monograph states that hypokalaemia from long-term laxative use interacts with antiarrhythmic medicinal products, with drugs that induce reversion to sinus rhythm such as quinidine, and with drugs inducing QT prolongation. The mechanism is potassium depletion prolonging cardiac repolarisation, not a pharmacokinetic effect of aloe constituents.
Clinical note: Regard concurrent use with a QT-prolonging drug as a contraindication rather than a caution, and advise patients on such drugs against self-medicating with aloe laxative products.
Orally administered medicines generally
The EMA monograph records plainly that the absorption of orally administered medicinal products may be reduced. Accelerated colonic transit shortens the time available for absorption, which matters most for drugs with a narrow therapeutic index or a long absorption window.
Clinical note: Separate essential oral medication from the aloe dose, which is taken at night. Watch particularly for loss of control on levothyroxine, antiepileptics and oral contraceptives.
Aloe vera inner-leaf gel and whole-leaf products supplied as Lu Hui
Three different materials circulate under the name aloe and are not interchangeable. Lu Hui is the concentrated dried leaf exudate, standardised to 18 to 28% hydroxyanthracene derivatives. Aloe vera inner-leaf gel or juice is decolorised and essentially anthranoid-free, so it is not a laxative at any dose and substituting it silently voids the prescription. Non-decolorised whole-leaf extract is a third thing again: a two-year drinking-water study found clear evidence of carcinogenic activity, with adenomas and carcinomas of the large intestine in male and female F344/N rats at 1 and 1.5%, and IARC classified Aloe vera non-decolorised whole leaf extract in Group 2B. There is also a sourcing dimension: Aloe ferox is listed in CITES Appendix II, so Cape aloes and its derivatives require CITES documentation for international trade, while Aloe vera (Aloe barbadensis) is annotated out of the Appendices. Material offered without CITES paperwork is unlikely to be genuine Aloe ferox.
Clinical note: Specify the dried leaf juice (aloes, aloe capensis or aloe barbadensis) with a hydroxyanthracene assay on the certificate of analysis, and reject anything described as gel, juice, whole-leaf or decolorised. For Cape aloes, ask the supplier for CITES documentation. In the EU, note that Commission Regulation (EU) 2021/468 prohibited aloe-emodin, emodin, danthron and Aloe leaf preparations containing hydroxyanthracene derivatives in food, and that the General Court annulled that regulation in November 2024 for everything except danthron, so the market position has changed twice in five years and should be checked rather than assumed.
Sevoflurane and antiplatelet agents
A 35-year-old woman lost 5 L of blood during resection of a haemangioma after taking oral Aloe vera tablets; the authors attributed a contributory role to an interaction with sevoflurane, on the basis that aloe constituents reduce prostaglandin synthesis and may inhibit secondary platelet aggregation while sevoflurane suppresses cyclooxygenase and prolongs bleeding time. The vascularity and size of the lesion were judged the dominant factors. The product involved was an Aloe vera tablet, not the standardised dried leaf juice that constitutes Lu Hui, so the relevance to this drug is indirect.
Clinical note: Stop aloe preparations at least a week before elective surgery, as for other herbs with possible antiplatelet activity, and record them on the pre-operative medication list.
Pregnancy, breastfeeding and children under 12
The EMA monograph does not recommend use in pregnancy because of experimental genotoxicity data on anthranoids including emodin and aloe-emodin, does not recommend breastfeeding because data on excretion of metabolites in milk are insufficient, and contraindicates use in children under 12. It further contraindicates aloes in intestinal obstruction or stenosis, atony, appendicitis, inflammatory bowel disease including Crohn disease and ulcerative colitis, abdominal pain of unknown origin, and severe dehydration with electrolyte depletion. Classical Chinese practice reaches the same conclusion by a different route, contraindicating Lu Hui in Spleen and Stomach deficiency, poor appetite and loose stool, and in pregnancy.
Clinical note: Do not prescribe in pregnancy, lactation or to children. Restrict to short-term use for occasional constipation, use the smallest dose that produces a soft formed stool, and investigate the cause if a laxative is needed daily. Chronic use also causes pseudomelanosis coli, which is reversible on stopping.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction, or powder/pills | 2–5 g | Daily | — | — | 中国药典 2020 【用法与用量】2～5g，宜入丸散。外用适量，研末敷患处。 【注意】孕妇慎用。 【性味与归经】苦，寒。归肝、胃、大肠经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
Bitter-cold purging of heat combined with heavy settling and clearing of the Heart, which moves the bowels while calming irritability.
Heat constipation with irritability and insomnia. Zhu Sha contains mercury and must never be heated or taken long term; Lu Hui is contraindicated in pregnancy.
Core pair of a classical formula — Geng Yi Wan, Xian Xing Zhai Yi Xue Guang Bi Ji (Miao Xiyong)
Evidence Tier
Strong evidence · 2 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
1
0 verified · 1 unverified
Show the study
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
1
1 verified · 0 unverified
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
Clear Evidence of Carcinogenic Activity by a Whole-Leaf Extract of Aloe barbadensis Miller (Aloe vera) in F344/N Rats
Two-year drinking-water studies in F344/N rats (0.5, 1 and 1.5%) and B6C3F1 mice (1, 2 and 3%) with a non-decolorised Aloe vera whole-leaf extract. Adenomas and carcinomas of the ileo-caecal and caecal-colic junction, caecum and ascending and transverse colon were significantly increased in male and female rats at 1 and 1.5%; survival fell in the 1.5% female group. No large-intestine neoplasms occurred in mice or at 0.5% in rats, but mucosal and goblet cell hyperplasia were seen in both species. The conclusion was that the extract is an intestinal irritant in both species and a large-intestine carcinogen in rats. This underpins the IARC Group 2B classification of Aloe vera non-decolorised whole leaf extract. The material tested was whole-leaf extract, not the pharmacopoeial dried leaf juice that Lu Hui is, but the anthranoid-rich fraction is common to both.
Safety of hydroxyanthracene derivatives for use in food
Risk assessment of hydroxyanthracene derivatives in food. The Panel concluded that aloe-emodin and emodin, and the structurally related danthron, are genotoxic in vitro, that aloe-emodin is genotoxic in vivo, and that the carcinogenicity of aloe extracts is a concern; it was unable to set a daily intake of hydroxyanthracene derivatives that does not give rise to concerns about harmful effects. This opinion is the scientific basis of Commission Regulation (EU) 2021/468, and therefore of the regulatory position on the drug in Europe.
⚠ 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/625788/2015 — European Union herbal monograph on Aloe barbadensis Mill. and on Aloe (various species, mainly Aloe ferox Mill. and its hybrids), folii succus siccatus (Final – first systematic review, adopted 22 November 2016), §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
Yao Xing Lun
Tang dynastyKai Bao Ben Cao
Song dynasty, 973 CEXuan Ming Lun Fang
Jin dynastyBen Cao Gang Mu
Ming dynastyReferences
- Committee on Herbal Medicinal Products (HMPC), European Medicines Agency. Community herbal monograph on Barbados aloes (Aloe barbadensis) and Cape aloes (Aloe capensis) . European Medicines Agency, EMEA/HMPC/76310/2006 (2006)
- Guo X, Mei N. Aloe vera: A review of toxicity and adverse clinical effects . Journal of Environmental Science and Health, Part C (2016) [DOI]
- Lee A, Chui PT, Aun CS, Gin T, Lau AS. Possible Interaction Between Sevoflurane and Aloe vera . Annals of Pharmacotherapy (2004) [DOI]
- Bottenberg MM, Wall GC, Harvey RL, Habib S. Oral Aloe Vera-Induced Hepatitis . Annals of Pharmacotherapy (2007) [DOI]
- Rabe C, Musch A, Schirmacher P, Kruis W, Hoffmann R. Acute hepatitis induced by an Aloe vera preparation: A case report . World Journal of Gastroenterology (2005) [DOI]
- Siegers CP, von Hertzberg-Lottin E, Otte M, Schneider B. Anthranoid laxative abuse--a risk for colorectal cancer? . Gut (1993) [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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