Lu Gan Shi炉甘石
Calamina · Calamine · Smithsonite · Zinc Carbonate Ore
Overview
- · — and the one benign entry in a sub-section otherwise made of mercury, arsenic and lead.*
A soft zinc carbonate ore, calcined and then levigated under water into an impalpably fine powder; the calcining converts it largely to zinc oxide. Sweet and neutral, it does two things and does them without toxicity: it dries a weeping, itching or ulcerated skin surface so that it can close, and it was the classical eye medicine — dusted or dropped into a red, swollen, gummy eye or one clouded by a superficial film. Western pharmacy arrived at almost the same preparation from a different direction, which is why calamine lotion sits in the same conceptual place. It is used externally only.
Nature & Flavor
Sweet · NeutralChannels
Liver · StomachTypical Dosage
**External use only, in an appropriate compounded amount** — the calcined, water-levigated powder dusted on, blended into an ointment, or made into a wash. Not taken internally. Ophthalmic use should be a properly manufactured sterile preparation, not a hand-ground powder.Actions
3 core actions
- Dries damp, stops itch, closes a soreWeeping eczema, damp itching lesions, ulcers with thin discharge that will not dry, and raw or excoriated skin. The powder absorbs and protects while the surface heals.
- Resolves toxin, brightens the eyesThe classical eye indication: red painful eyes, swollen and crusted lid margins, and a superficial film over the eye. Historically compounded into eye powders and drops.
- Calcined and levigated before useThe raw ore is not applied as it is. It is calcined, quenched, then ground under water so that only the finest particles are collected — a preparation step that matters most for the eye formulations, where a coarse grain would abrade the surface it is meant to soothe.
In Formulas
Formulas containing Lu Gan Shi
No published formula lists this herb yet — the library is growing.
Indications & Clinical Uses
- Weeping eczema, damp itch, raw or excoriated skin (external use)
- Ulcers and sores with thin discharge that will not dry (external use)
- Red swollen eyes, crusted lid margins, superficial corneal film (classical ophthalmic use, in a manufactured preparation)
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
External use only — Lu Gan Shi is not taken internally in any preparation or at any dose. It is the least dangerous item in this sub-section, but that is not the same as being without limits.
- Never swallowed. There is no internal dose. The pharmacopoeia lists it as an external drug.
- The eye is not a place for a home-ground powder. The classical ophthalmic use assumes a properly prepared, finely levigated and sterile product. Anything applied to the eye should be a manufactured preparation, and a red or painful eye that does not settle quickly needs to be examined rather than treated blind — a corneal ulcer, glaucoma or an injury will not announce itself in a herbal way.
- Not for a wound that is infected or heavily discharging. A drying powder over pus traps it. Clean and assess the wound first; the powder belongs on a surface that is trying to close.
- Contact irritation is uncommon but occurs; stop if the skin becomes red, sore or more itchy than before.
- Keep it out of the mouth and nose, and store it labelled — a fine white mineral powder in an unlabelled jar is a hazard for the reason every other entry in this sub-section demonstrates.
Contraindicated in pregnancy: No specific restriction in pregnancy or breastfeeding for external use — it is not absorbed in any meaningful amount from intact or lightly broken skin. Avoid applying it to the nipple while breastfeeding, and defer to the treating practitioner.
For licensed practitioners’ reference only
References
- Lu Gan Shi is a later addition to the Chinese materia medica; accounts of the first source text differ and it 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》(external use only; the calcining and water-levigation requirement).
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.