Aloe — Safety & Interactions

Lu Hui · Aloe

Contraindications

  • Pregnancy — absolutely contraindicated; aloin is a potent uterotonic causing uterine smooth muscle contractions; significant risk of miscarriage or premature labour at therapeutic doses; one of the most consistent pregnancy contraindications across all TCM and Western herbalism sources
  • Spleen-Stomach Deficiency Cold — bitter-cold nature severely injures digestive Yang; one of the primary traditional contraindications: fatigue, loose stools, cold limbs, and poor appetite all worsen with Lu Hui
  • Intestinal Cold patterns — Cold-type constipation and abdominal cold-pain; purgative warming strategy required, not cold draining
  • Inflammatory bowel disease (Crohn's disease, ulcerative colitis) — stimulant purgation exacerbates intestinal inflammation; anthraquinone irritant action contraindicated in active IBD
  • Children under 12 — stimulant anthraquinone laxatives not recommended in paediatric practice

Cautions

  • Standard dose: 0.6–1.5 g dried aloe powder in pill or powder form; 1–2 g maximum per dose; do NOT use as decoction (aloin is poorly extracted and bitter taste intolerable); short-term use only
  • Long-term use risk: chronic use >10 days causes electrolyte imbalance (hypokalemia), melanosis coli (brown pigment deposition in colonic mucosa — benign but a marker of chronic irritant laxative use), and potential laxative dependency
  • IARC classification: aloe-emodin and aloin are classified IARC Group 2B (possibly carcinogenic to humans) based on rodent bioassays at high doses; no confirmed human carcinogenicity; use short-term only at therapeutic doses
  • Distinguish TCM Lu Hui (dried latex exudate, anthraquinone-rich) from cosmetic aloe vera gel (inner clear gel, acemannan-rich, minimal aloin) — the purgative and uterotonic contraindications apply to the dried latex/TCM drug, not the gel

Drug Interactions

Drug Class / Substrate Mechanism Severity Source
Cardiac glycosides (digoxin, digitoxin) — CONTRAINDICATED: aloin-induced purgation causes hypokalemia, which dramatically potentiates cardiac glycoside toxicity and arrhythmia risk; do not use Lu Hui in any patient on cardiac glycosides
Loop diuretics (furosemide, bumetanide) and thiazide diuretics — additive hypokalemia risk; combination accelerates potassium depletion; monitor electrolytes if concurrent use unavoidable
Antidiabetic medications (insulin, metformin, sulfonylureas) — additive glucose-lowering effect from aloe gel fraction; risk of hypoglycaemia in medicated diabetics; monitor blood glucose
Anticoagulants (warfarin) — emodin and aloe-emodin have mild anticoagulant activity in vitro; potential to enhance anticoagulant effect; monitor INR

Pregnancy

Not recommended during pregnancy. Consult a qualified practitioner before any use.

This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before using herbal medicines, especially if you take prescription medications.