Li Lu (Veratrum Root and Rhizome)

Chinese Herb Actions

Chinese Herb Dosage

• What is the dosage of Li Lu, and is it still used internally?

  Materia medica references cite an unusually small internal range — roughly 0.3–0.9 g, in pill or powder form and traditionally not decocted — one of the narrowest safety margins of any substance in the Chinese pharmacopoeia. Because that margin is so difficult to control, many practitioners avoid internal use of Li Lu altogether, and contemporary clinical use is largely confined to external (topical) preparations. This is reference information about the herb’s historically documented dose ceiling, not a preparation or use instruction.

  Note: some clinical TCM references cite an even lower internal ceiling (around 0.1–0.15 g), and case reports elsewhere describe fatal outcomes at doses in a comparably low range. Sources agree the margin is extremely narrow and source-dependent; we report the range rather than a single figure, and omit any figure we could not cross-check.

  Source: materia medica consensus (Bensky-style range, cross-checked against clinical TCM references citing a lower ceiling). Reference only — not a prescription or preparation instruction; toxic-herb caution applies.

Chinese Herb Contraindications & Cautions

• Are there cautions or incompatibilities for Li Lu?

  Li Lu is flagged in the site’s database as very toxic, and the materia medica contraindicates it for weak, deficient, or pregnant patients — it is reserved, if at all, for qualified professional use. It is also one of the anchor herbs of the classical Eighteen Incompatibilities (十八反, shí bā fǎn): the traditional mnemonic verse holds that the ginseng-type tonics (“shen”), Xi Xin, and the peony-type herbs (“shao”) all “rebel against” (antagonize) Li Lu — meaning the pairing is classically avoided because combining them is held to cause or worsen adverse effects, not to produce any therapeutic benefit.

  The site’s own incompatibility records list Li Lu as incompatible with:

  • Ren Shen and Dang Shen (ginseng-type qi tonics)
  • Bei Sha Shen and Sha Shen (the sha shen group)
  • Xuan Shen, Dan Shen, and Ku Shen (the remaining “shen”-named herbs)
  • Xi Xin
  • Bai Shao and Chi Shao (the peony-type “shao” herbs)

  Source: Sacred Lotus herb-incompatibility records (herb_cautions), cross-checked against the classical Eighteen Incompatibilities enumeration; materia medica consensus on contraindications. Reference only, not usage guidance.

Chinese Herb Toxicity & Overdose

• Is Li Lu toxic, and what causes its toxicity?

  Yes — Li Lu is classed as very toxic, and the site flags it accordingly. Its toxicity is attributed to steroidal ester alkaloids — principally veratramine and jervine (reported as the two largest fractions of total alkaloid content), alongside cevadine, protoveratrine A/B, and related cevanine-type alkaloids. Pharmacology literature describes these compounds acting on voltage-gated sodium channels in nerve and cardiac tissue; the classic toxicological picture (the “veratrum effect”) is early vomiting and abdominal upset from vagal-nerve overstimulation, followed by bradycardia, hypotension, and cardiac-conduction disturbance, with severe poisoning potentially fatal. A rat acute-toxicity study places the oral LD50 of Veratrum nigrum extract at roughly 2.6 g/kg — a low figure consistent with a narrow safety margin.

  Note: most of the detailed human poisoning literature concerns related Veratrum species (V. album, V. viride, V. lobelianum) ingested after being mistaken for edible plants, rather than V. nigrum specifically. These species share the same class of steroidal ester alkaloids and produce the same clinical picture, so we use them here as cross-species toxicological reference — not as species-specific studies of the TCM herb Li Lu.

  Source: PubMed 38663784 (2024 comprehensive review of V. nigrum: ethnopharmacology, phytochemistry, pharmacology, toxicity, incompatibility); PubMed 25024734 (acute-toxicity/LD50 study of V. nigrum); PubMed 35878228 (cardiotoxicity mechanism study, V. lobelianum); PubMed 16958554 (Veratrum poisoning, toxicology review); PubMed 2362117 (V. viride poisoning case series); PubMed 21171854 (V. album poisoning case series). Toxicology reference, not a safety guarantee.

• This herb is considered toxic.
  (while some Chinese herbs are toxic, it must be noted that many come prepared, or are combined, to mitigate their toxicity)

Herb-Drug Interactions

• No dedicated clinical herb–drug interaction studies for Li Lu are established. Because its toxic alkaloids act on cardiac sodium channels and produce vagally mediated bradycardia and hypotension, reference sources would reasonably flag added caution alongside antiarrhythmic medications, beta-blockers or other heart-rate-lowering drugs, and antihypertensives, given the risk of additive effects on heart rate and blood pressure. This is precautionary, drawn from the toxicology mechanism, not a demonstrated clinical interaction. (Flagged for practitioner confirmation.)

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Li Lu (Veratrum nigrum / Radix et Rhizoma Veratri)?

  Yes for chemistry, pharmacokinetics, and toxicology — but essentially no modern human-clinical research exists, consistent with the herb’s narrow safety margin and largely external contemporary use. Chemically, roughly 137 compounds have been isolated from V. nigrum, dominated by steroidal alkaloids (veratramine and jervine are reported as the two largest fractions), alongside stilbenes, flavonoids, and organic acids.

  • Pharmacokinetics — veratramine and jervine show high bioavailability in rats, with a marked sex difference: male rats showed roughly 10× higher absorption and roughly 20× lower elimination than females for the same dose, implying greater accumulation risk in males; jervine has separately been shown to undergo enterohepatic circulation. Preclinical, not a human-dosing finding.
  • Toxicology and a modern rationale for the classical incompatibility — an acute-toxicity study reported the oral LD50 of V. nigrum extract at roughly 2.6 g/kg in rats, and found that combining it with Radix paeoniae alba (Bai Shao) shifted mortality depending on the dose ratio; in cultured neuronal cells, the Bai Shao constituent paeoniflorin appeared to offset veratridine-type toxicity. This offers a preclinical, mechanistic rationale for the classical “Eighteen Incompatibilities” pairing of Li Lu with the peony-type herbs, though the same study found the relationship is ratio-dependent, not simply “always more toxic together.”
  • Cardiotoxicity mechanism — alkaloid-docking and clinical case work on the related species V. lobelianum implicates direct binding to the cardiac sodium channel NaV1.5 (jervine, protoveratrine A, protoveratrine B) as a driver of the bradycardia and hypotension seen after Veratrum poisoning.
  • Species and quality-control profiling — HPLC-MS/MS methods now quantify five marker alkaloids (cevadine, jervine, protoveratrine A, veratramine, veratridine) across three Veratrum species including V. nigrum, supporting authentication and quality control of the raw drug.

  Note: the cardiotoxicity-mechanism and several poisoning-case sources above concern related Veratrum species rather than V. nigrum itself; we include them as cross-species pharmacological/toxicological context for the same alkaloid class, flagged accordingly rather than presented as species-specific findings.

  Sources: PubMed 38663784 (comprehensive review); PubMed 38863228 (HPLC-MS/MS marker-alkaloid profiling, three Veratrum species); PubMed 35785141 (pharmacokinetics of veratramine and jervine, sex differences); PubMed 31929946 (jervine enterohepatic circulation); PubMed 25024734 (acute toxicity / Bai Shao incompatibility study); PubMed 35878228 (cardiotoxicity mechanism, V. lobelianum); PubMed 16958554, PubMed 2362117, PubMed 21171854 (Veratrum-genus poisoning case literature). Research context, not a therapeutic claim.

Chinese Herb Notes

• How does Li Lu differ from other emetic herbs like Gua Di and Chang Shan?

  All three are grouped in the materia medica as herbs that induce vomiting, but Li Lu is by far the most toxic and is distinguished by its added external parasiticide use. The site’s own identity records show the difference in channels and toxicity grade.

  • Li Lu (Liver, Lung, Stomach; Spicy, Bitter, Cold, Toxic) — the strongest of the three; directed at stubborn phlegm-turbidity (wind-stroke, epilepsy/mania) and, uniquely among the group, also used topically to kill parasites and stop itching.
  • Gua Di (melon pedicel; Stomach; Bitter, Cold, Slightly Toxic) — a milder emetic directed at food or phlegm-damp stagnating in the chest and epigastrium.
  • Chang Shan (dichroa root; Heart, Liver, Lung; Bitter, Spicy, Cold, Toxic) — toxic like Li Lu, but classically distinguished by its use for recalcitrant, malarial-type disorders alongside phlegm expulsion.

  Li Lu does not appear in any classical formula recorded in the site’s database — consistent with its narrow safety margin and largely external contemporary use.

  Source: Sacred Lotus sources & references fields for Li Lu, Gua Di and Chang Shan; materia medica category grouping (“herbs that induce vomiting”).

This herb is incompatible with:

• Bai Shao (Radix Albus Paeoniae Lactiflorae)
• Bei Sha Shen (Radix Glehniae Littoralis)
• Chi Shao (Radix Rubrus Paeoniae Lactiflorae)
• Dan Shen (Radix Salviae Miltiorrhizae)
• Dang Shen (Radix Codonopsitis Pilosulae)
• Ku Shen (Radix Sophorae Flavescentis)
• Ren Shen (Radix Ginseng)
• Xi Xin (Herba Asari Cum Radice)
• Xuan Shen (Radix Scrophulariae Ningpoensis)
• Sha Shen (Glehniae/Adenophorae Radix)

This herb is considered toxic