Qing Fen轻粉
Calomelas · Calomel · Mercurous Chloride
Overview
- ·.*
A white, weightless crystalline powder — mercurous chloride, made by subliming mercury with alum and salt. Acrid, cold and toxic, it kills the organisms of scabies and ringworm, dries a weeping eczema and eats away rotten tissue on an ulcer, and it was for centuries the standard treatment for syphilitic sores in China. It also has a second life that is easy to forget: as calomel, the same compound was a mainstay of Western medicine — a purgative, a teething powder, a diuretic — until the middle of the twentieth century, when it was withdrawn after it was shown to cause acrodynia, the pink disease that killed and disabled children given it routinely. It is the same substance in both traditions and it carries the same mercury. This entry records what the materia medica teaches; internal use is obsolete and external use is restricted or prohibited in most Western jurisdictions.
Nature & Flavor
Acrid · Cold · ToxicChannels
Large Intestine · Small IntestineTypical Dosage
0.1–0.2 gActions
4 core actions
- Kills parasites, stops itchScabies, ringworm and other parasitic skin disease, and the itch that comes with them — the classical external indication and the one it was most used for.
- Attacks toxin, clears rotten tissueSyphilitic and other stubborn sores, ulcers with sloughy tissue, weeping eczema, chronic scalp and mouth lesions — applied as a powder or in an ointment.
- Dries a weeping surfaceDamp, oozing skin lesions that will not dry, including rosacea-type facial eruption in the classical record.
- Drives water downwardThe classical internal use for oedema, abdominal distension and blocked bowel — recorded here as history. It is the use that produced the mercury poisonings, and it has been abandoned in every tradition that once used it.
In Formulas
Formulas containing Qing Fen
Indications & Clinical Uses
- Scabies, ringworm and parasitic itch — external use
- Syphilitic and other chronic sores, sloughy ulcers, weeping eczema — external use
- Chronic scalp and oral lesions, rosacea-type eruption in the classical record
- Oedema, abdominal distension, constipation (classical internal use, obsolete)
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
Qing Fen is mercurous chloride — a mercury compound, toxic. Read this entry as a record of the classical materia medica, not as a treatment recommendation.
- Do not take it internally. The classical 0.1–0.2 g dose is recorded above for completeness; it is obsolete. Swallowed mercury salts cause a metallic taste, inflamed and bleeding gums with loosening teeth, heavy salivation, abdominal pain and diarrhoea, and kidney injury; children given calomel routinely developed acrodynia — painful pink swollen hands and feet, irritability, insomnia, hypertension — and some died. That history is the reason the compound was withdrawn from Western practice.
- External use is still mercury. It is absorbed through broken, weeping and ulcerated skin. Use it on a small area only, for a short defined course, never over a large surface, never on a large wound or burn, never on mucous membranes and never near the eyes.
- Never on children or infants, never in pregnancy or breastfeeding, and never in anyone with kidney or liver impairment.
- Never heated, never combined with other mercury-containing preparations, and never used with iodide- or bromide-containing products, which can convert it into more soluble and more toxic mercury salts.
- Rinse the mouth after any oral preparation was the classical instruction, because the compound ulcerates the mouth directly. Take it as a warning about the substance rather than as a way of making the internal route acceptable.
- Legal status. Mercury in medicines is prohibited or tightly restricted across the EU, the UK, the US, Canada and Australia. A practitioner outside China generally cannot legally supply it — confirm your own regulator's position.
- What is used instead. Scabies and ringworm have specific, safe, effective modern treatments, and both need the diagnosis confirmed rather than a powder applied. For the wound-cleaning role, see the note under Hong Fen 红粉.
Contraindicated in pregnancy: Contraindicated in pregnancy and while breastfeeding, internally and externally — mercury crosses the placenta and passes into breast milk.
For licensed practitioners’ reference only
References
- Qing Fen enters the Chinese materia medica through the Tang–Song 本草 literature; the specific first source varies between accounts and is not asserted here.
2. Bensky, Clavey & Stöger. Chinese Herbal Medicine: Materia Medica, 3rd ed.
3. 《中华人民共和国药典》(the 0.1–0.2 g internal limit and the caution against prolonged use).
4. The withdrawal of calomel from paediatric use following the recognition of acrodynia is documented in the twentieth-century medical literature.
5. Mercury in medicinal products is restricted or prohibited in most Western jurisdictions — confirm the current position with your own regulator.
Professional reference notice. Entries are scholarly references for licensed TCM practitioners and students — not medical advice, and not a recommendation to self-prescribe. Chinese herbal formulas should be used under the guidance of a qualified practitioner. Content is an original editorial compilation by Cura x Cura, cross-checked against the cited references.