Traditionally used for
- Cough & breathing
- Nerves & recovery
- Skin
Cautions & contraindications
- Pregnancy
- Young children
- Seizure disorders
- Toxic — professional use only
☯ TCM Properties
Absorbs fluids, r educes swelling and stops bleeding; Eliminates toxins and kills parasites topically; Drives Phlegm downward and suppresses childhood convulsions; Calms fright
Traditional Chinese Uses
Safety warning: Mi Tuo Seng is litharge, a mineral of lead(II) oxide (PbO). It is toxic; internal use readily causes lead poisoning (abdominal colic, anemia, neuromuscular damage) and it is contraindicated in pregnancy, in children and in the weak. It is used externally only, in powder or paste, and modern practice heavily restricts or avoids it.
Traditionally classed for external application, it is salty and pungent and neutral, entering the Liver, Spleen and Large Intestine channels. Applied topically it absorbs fluids and dries Damp, reduces swelling, stops bleeding, resolves toxicity and kills parasites, and astringes and heals sores—used for eczema, scabies, tinea (ringworm), axillary odor, ulcers and non-healing wounds. Older texts also record internal use to drive Phlegm downward and calm childhood fright and convulsions, but this is unsafe and obsolete given the lead content.
Relationships
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Botanical Description
Mi Tuo Seng is litharge, a mineral substance consisting principally of lead(II) oxide (PbO) and historically obtained as a by-product of silver smelting or by deliberate roasting of metallic lead. The material appears as heavy, brittle, yellow to orange-red, scaly or earthy masses that are readily reduced to a fine powder. It has no botanical origin and is therefore not a plant. Classical Chinese pharmacy employed Mi Tuo Seng chiefly as an external preparation for skin lesions and traumatic sores, but its severe toxicity is now thoroughly established: lead is a cumulative neurotoxin and nephrotoxin causing irreversible harm at low doses, and internal administration has been abandoned in modern practice. External use is also strongly cautioned against, particularly on broken skin or in vulnerable patients.
Active Constituents
Lead(II) oxide (PbO)
Lead oxide; the mineral litharge is the tetragonal polymorph of PbO, massicot the orthorhombic oneConcentration: The bulk of the drug. Pure PbO is 92.8 percent lead by mass. Commercial Mi Tuo Seng is crude, not reagent-grade: Chinese materia medica descriptions define it as 粗制氧化铅, the furnace-bottom byproduct of cupelling galena for silver and lead, which is why its synonyms are 炉底, 金炉底 and 银炉底.
This is the whole safety problem with the drug. Unlike the inert mineral drugs (fluorite, barite, talc), PbO is amphoteric and dissolves readily in dilute acid, so gastric acid converts it to soluble Pb2+ and it is substantially bioavailable by mouth; it is also absorbed across broken skin and mucosa. Absorbed lead substitutes for calcium and zinc at their binding sites, inhibits delta-aminolevulinic acid dehydratase and ferrochelatase in haem synthesis (hence anaemia with basophilic stippling), and crosses the blood-brain barrier by mimicking the divalent calcium ion.
Metallic lead and lead dioxide (PbO2)
Elemental lead and lead(IV) oxide; unreacted smelting residuesConcentration: Minor inclusions. Standard Chinese materia medica entries list 金属铅 and 二氧化铅 among the 夹杂物 of the crude drug alongside sand and gangue.
Metallic lead dissolves far more slowly than PbO but adds to the total lead burden of a dose. PbO2 is a strong oxidant and is reduced to soluble Pb2+ under gastric conditions. Neither is removed by the traditional processing of the drug.
Basic lead carbonate (hydrocerussite)
Lead carbonate; storage weathering productConcentration: Accumulates progressively on the surface with time in store; the drug is described as slowly absorbing atmospheric carbon dioxide and converting to 碱式碳酸铅.
Chemically the same compound as white lead, the pigment behind classical painters' colic. It dissolves in gastric acid at least as readily as PbO, so an aged sample is not a safer sample. It means the lead speciation of the drug drifts in storage and cannot be assumed from the label.
Antimony, iron, calcium and magnesium
Trace metal and metalloid impurities from cupellationConcentration: Trace. Materia medica descriptions list 微量铅, 锑, 铁, 钙, 镁 as the minor elements of the crude drug; smelter-derived litharge composition varies with the ore, so a batch figure cannot be assumed.
Antimony is itself an emetic and cardiotoxic metalloid, and cupellation of argentiferous galena concentrates it along with silver, copper, bismuth and arsenic into the furnace product. There is no published elemental survey of commercial Mi Tuo Seng batches, so the non-lead trace load of any given sample is simply unknown.
Siliceous gangue (sand and rock residue)
Insoluble silicate and oxide gangueConcentration: Variable; listed as 砂石 among the impurities.
Pharmacologically inert diluent. Its practical significance is that it makes the lead content of a given weight of drug variable and unpredictable, so dose cannot be inferred from mass.
Regulatory limits on arsenic, lead, cadmium and mercury
Quality-control status (not a chemical constituent)Concentration: None exist. Mi Tuo Seng is not in the Pharmacopoeia of the People's Republic of China, so no ChP monograph, assay or heavy-metal limit applies to it.
Stated plainly because the absence is easy to misread as safety: there is no Pharmacopoeial As/Pb/Cd/Hg specification for this drug because the drug itself has been dropped from the Pharmacopoeia, lead no longer being accepted as a medicinal material. The ChP general methods 2321 (lead, cadmium, arsenic, mercury, copper) and 0821/0822 exist, but ChP 2020 applies element limits to named individual medicinal materials rather than as a blanket rule, and Mi Tuo Seng is not among them. A limit would in any case be incoherent for a drug whose active principle is the contaminant.
⚠ Drug Interactions
Lang Du (Radix Euphorbiae Fischerianae / Radix Stellerae Chamaejasmes)
The Nineteen Antagonisms (十九畏) verse names this pair directly: 狼毒最怕密陀僧, Lang Du most fears Mi Tuo Seng. The verse is transmitted in the Ming compilation Zhen Zhu Nang Bu Yi Yao Xing Fu, with some bibliographers tracing its first appearance to Liu Chun's Yi Jing Xiao Xue of 1388. The prohibition is doctrinal: no modern pharmacological or clinical study has tested the pair, and no mechanism has been demonstrated. What is not doctrinal is that the combination stacks two toxic drugs — a diterpene-ester-bearing root and a soluble lead oxide — so the classical rule and modern toxicology point the same way even though the classical reasoning is not evidence.
Clinical note: Do not combine. The classical contraindication is universally recorded in the materia medica and there is no clinical circumstance that would justify testing it.
Qian Dan / Hong Dan (Minium, lead tetroxide Pb3O4)
Mi Tuo Seng (PbO) and Qian Dan or Hong Dan (Pb3O4) are different lead oxides that occupy overlapping roles in topical Chinese practice, particularly as the base of black plasters, and are substituted for one another in the market and in homemade preparations. Almost all of the published Chinese lead-poisoning case literature that has been chemically characterised implicates the tetroxide rather than the monoxide: Lin et al. found 16 samples of Hongdan averaging 817,000 mg/kg lead, mainly Pb3O4, poisoning two young children (blood lead 303 and 385 micrograms/L) when it was used in place of baby powder; Wu et al. reported a Hong-dan anal preparation containing lead tetroxide plus arsenic and mercury. Because the two are interchanged, a Mi Tuo Seng prescription is not a guarantee of which lead oxide the patient actually received, and exposure to both is additive with no threshold.
Clinical note: Treat any prescription naming either drug as a lead exposure, and never assume the dispensed material is the one named. If a patient reports either, obtain a blood lead level rather than relying on the label.
Iron and calcium supplements (and iron or calcium deficiency)
Divalent lead is taken up across the enterocyte by the divalent metal transporter DMT1, the same route as iron, and competes with calcium for absorption and for binding sites once absorbed. Iron-deficient and calcium-deficient individuals therefore absorb a markedly larger fraction of an ingested lead dose, which is a principal reason paediatric lead poisoning from traditional remedies is so severe. Repletion of iron and calcium reduces, but does not abolish, absorption.
Clinical note: This is not a reason to give the drug with supplements. It is a reason to recognise that malnourished children, pregnant women and iron-deficient patients — exactly the groups classically given calming and anticonvulsant mineral drugs — are the ones a given exposure will harm most.
Succimer (DMSA), edetate calcium disodium and dimercaprol
Chelation only works once exposure has stopped. In the published cases, blood lead normalised after the traditional medicine was discontinued and chelation given — Tang et al. required three rounds of chelation in a patient whose homemade preparation assayed over 4,000 mg/kg lead; Wu et al. achieved recovery with EDTA and DMSA only after the herbal patch (517 mg/g lead) was removed. Chelating a patient who is still taking or applying the drug mobilises lead without removing the reservoir, and chelators can increase gastrointestinal absorption of lead still present in the gut. Peripheral neuropathy persisted four years after chelation in one of Wu's cases, so chelation does not undo the damage.
Clinical note: Stop the drug first, confirm by history that no other lead-containing remedy remains in use, then refer for blood lead measurement and specialist toxicology management. Do not initiate outpatient oral chelation while the source is still in the household.
Proton pump inhibitors and antacids
PbO dissolution in the stomach is acid-dependent, so raising gastric pH with a proton pump inhibitor or an antacid should reduce the soluble Pb2+ fraction available for absorption, while an acidic co-ingestant should increase it. This is inference from the chemistry of lead monoxide, not a measured pharmacokinetic interaction, and no study has quantified it for this drug.
Clinical note: Do not treat acid suppression as protective. It is recorded here only so that a practitioner does not misread a low measured absorption in one patient as evidence that the drug is safe in another.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| topical | Appropriate amount | — | — | — | No Chinese Pharmacopoeia 2025 monograph for this drug, so no pharmacopoeial dose is given here. EXTERNAL USE ONLY. Litharge (PbO) is ground and applied to sores, eczema, tinea and ulcers, and used in plasters. Lead is a cumulative poison; there is no established safe internal dose and it must not be swallowed. Contraindicated in pregnancy. The stored value of 6-15 g as a decoction was filler and was dangerous. The previous value was generic filler generated from tcm_category and has been removed rather than replaced with an estimate. |
Evidence Tier
Moderate evidence · 7 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
0
Other clinical trial
0
Observational / case report
5
5 verified · 0 unverified
Show 5 studies
- Lead Poisoning Caused by Traditional Chinese Medicine: A Case Report and Literature Review
- Childhood lead poisoning associated with traditional Chinese medicine: A case report and the subsequent lead source inquiry
- Lead, Mercury, and Arsenic Poisoning Due to Topical Use of Traditional Chinese Medicines
- Non-occupational lead poisoning associated with traditional Chinese medicine: A case report
- Lead Poisoning in a Mother and Her Four Children Using a Traditional Eye Cosmetic — New York City, 2012–2023
In vitro / animal
1
0 verified · 1 unverified
Other / unclassified
1
1 verified · 0 unverified
Show the study
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Lead Encephalopathy Due to Traditional Medicines
Systematic review of case reports of lead encephalopathy attributable to traditional medicines, searching MEDLINE, CINAHL, AMED, CISCOM, EMBASE and the Cochrane Library from 1966 to February 2007 with no language restriction. Seventy-six cases were identified: 66 (87 percent) from Middle Eastern traditional medicines, 5 (7 percent) from Ayurvedic medicines and 5 (7 percent) from other traditions. Ninety-five percent were infants and young children; of those 72 paediatric cases, 8 (11 percent) died and at least 15 (21 percent) were left with residual neurological deficits. The review is of lead-containing traditional remedies generally rather than of Mi Tuo Seng specifically, and the encephalopathy it documents is the endpoint that an orally dosed lead oxide can produce.
Lead Poisoning Caused by Traditional Chinese Medicine: A Case Report and Literature Review
A 66-year-old man presented with periumbilical pain and constipation after eight months of a homemade Chinese medicinal preparation. His blood lead was 657 micrograms/L and his asymptomatic wife's was 488 micrograms/L; the preparation assayed at more than 4,000 mg/kg lead. Both stopped the medicine and the husband received chelation, with pain relief and normalisation of blood lead after three rounds. The accompanying literature review attributes lead poisoning from Chinese medicine to intentional or unintentional incorporation of lead-containing bases and pastes, and calls for tighter regulation of small private clinics. The lead compound in this particular preparation was not speciated.
Childhood lead poisoning associated with traditional Chinese medicine: A case report and the subsequent lead source inquiry
Two children in Guangzhou, a 3-year-old boy (blood lead 303 micrograms/L) and his 6-month-old sister (385 micrograms/L), were hospitalised after a traditional powder was used on their skin in place of baby powder for dermatitis. The powder contained 214,000 mg/kg lead, traced to deliberate addition of Hongdan to talcum. Sixteen Hongdan samples collected in Ganzhou averaged 817,000 mg/kg lead, predominantly lead tetroxide (Pb3O4). This documents the closely related lead oxide rather than litharge itself, and it documents systemic poisoning by the dermal route in infants.
Lead, Mercury, and Arsenic Poisoning Due to Topical Use of Traditional Chinese Medicines
Two cases of heavy metal poisoning by the mucocutaneous route, confirmed toxicologically. A 51-year-old man used a hong-dan mixture anally for two weeks for anal fistula and developed perianal gangrene, fever, rash, anaemia, hair loss, peripheral neuropathy and muscle atrophy; the mixture contained lead tetraoxide, arsenic and mercury, and his neuropathy persisted four years after chelation. A 75-year-old man using a herbal patch for a chronic leg ulcer for three months had a blood lead of 226 micrograms/dL with a patch lead content of 517 mg/g, recovering after EDTA and DMSA. The relevance to Mi Tuo Seng is direct: this is the topical, plaster-and-paste route in which crude lead oxides are actually used, and damaged or infected tissue absorbed enough to cause life-threatening systemic poisoning within weeks.
Non-occupational lead poisoning associated with traditional Chinese medicine: A case report
A 21-year-old man presented with severe colicky periumbilical pain after a year of taking a Chinese medicinal preparation for facial acne. He had anaemia, liver injury, basophilic stippling on bone marrow smear and a blood lead of 1,268.4 micrograms/L. He recovered with lead-elimination treatment. The authors emphasise that this presentation is repeatedly misdiagnosed and that drug history must be taken explicitly. The lead source was not chemically speciated.
Lead Poisoning in a Mother and Her Four Children Using a Traditional Eye Cosmetic — New York City, 2012–2023
A family cluster in which a mother and four children had elevated blood lead traced to a traditional eye cosmetic (surma) brought from Pakistan; the product assayed at 390,000 ppm lead. Included here because lead oxides and sulfides used cosmetically and medicinally are the same class of exposure as Mi Tuo Seng, and because it shows how long an unrecognised traditional-product lead source can persist within a household — in this instance across more than a decade.
Toxic Element Contamination of Natural Health Products and Pharmaceutical Preparations
Analytical survey using high-resolution ICP-MS of the toxic element content of a range of natural health products and pharmaceutical preparations, establishing that measurable lead and other toxic elements occur in commercially available preparations. Cited here as the analytical background against which a deliberately lead-based drug should be judged, not as a study of Mi Tuo Seng.
⚠ Safety & Contraindications
- Pregnancy
- Young children
- Seizure disorders
- Toxic — professional use only
Contraindications
Its use is prohibited in the weak, pregnant women, and children, and cautious for oral use. Don’t take overdose and use more than a week.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, p. 416.
⚠ 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.
Incompatibilities (十八反 / 十九畏)
- 十九畏: Lang Du × Mi Tuo Seng — avoid combining with Lang Du / Euphorbia fischeriana
Historical Texts
Tang Ben Cao (Xin Xiu Ben Cao, Newly Revised Materia Medica)
Tang dynasty, 659 CELei Gong Pao Zhi Lun (Master Lei's Treatise on Preparing Drugs)
Traditionally attributed to the Liu Song period, 5th century CE; surviving text reconstructed from later quotationZhen Zhu Nang Bu Yi Yao Xing Fu (Supplemented Rhymed Verses on Drug Properties from the Pearl Bag), transmitting the Nineteen Antagonisms verse; some bibliographers trace the verse's first appearance to Liu Chun's Yi Jing Xiao Xue of 1388
Ming dynasty, 14th–16th centuryBen Cao Gang Mu (Compendium of Materia Medica), Li Shizhen
Ming dynasty, 1596Pharmacopoeia of the People's Republic of China (current editions), by omission
Modern, 20th–21st centuryReferences
- EFSA Panel on Contaminants in the Food Chain (CONTAM). Scientific Opinion on Lead in Food . EFSA Journal (2010) [DOI]
- Shi J, Yang Y, Zhou X, Zhao L, Li X, Yusuf A, Hosseini MSMZ, Sefidkon F, et al.. The current status of old traditional medicine introduced from Persia to China . Frontiers in Pharmacology (2022) [DOI]
- Duan X, Cao S, Guan J, Hu L, Sun C, Yan C. A more scientific blood lead reference value urgently needs to be updated in China: From a national and international insight . Eco-Environment & Health (2025) [DOI]
- Inada I, Kiuchi F, Urushihara H. Comparison of Regulations for Arsenic and Heavy Metals in Herbal Medicines Using Pharmacopoeias of Nine Counties/Regions . Therapeutic Innovation & Regulatory Science (2023) [DOI]
- Dai M, Wang D. Mineral medicines of the East: an analysis of records in historical Chinese and Japanese medical texts . Frontiers in Pharmacology (2025) [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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