Gan Qi干漆
Toxicodendri Resina · Dried Lacquer · Lacquer Tree Resin
Overview
- ·.*
The hardened sap of the lacquer tree, Toxicodendron vernicifluum — the same material that coats lacquerware, dried, broken up and then calcined until it stops smoking before it is used as a medicine. Acrid and warm, and marked, it belongs to the small group of herbs classed as: not merely moving blood but breaking it, for amenorrhoea from long-standing stasis and for fixed abdominal masses. The classical texts also credit it with killing intestinal parasites.
Two things dominate its practical handling. It is a strong blood-breaker, so it is contraindicated in pregnancy and in anyone without genuine stasis; and it is a potent contact allergen, because lacquer sap contains urushiol — the same chemical family as poison ivy. It appears in Da Huang Zhe Chong Wan 大黄䗪虫丸, the Jin Gui formula for entrenched internal stasis, and outside prescriptions of that kind it is rarely reached for today.
Nature & Flavor
Acrid · Warm · ToxicChannels
Liver · SpleenTypical Dosage
2–5 g a day, in pills or powder, and only after calcining (— roasted until the smoke stops, which drives off the volatile irritant fraction). It is not put into a decoction and the raw resin is not taken internally.Actions
3 core actions
- Breaks blood stasis, opens closed mensesAmenorrhoea from entrenched blood stasis, with fixed, stabbing lower abdominal pain and dark clotted flow when it does come. This is a forceful action for an established, obstinate pattern, not for ordinary period pain.
- Disperses fixed massesPalpable, fixed abdominal masses of long standing. Da Huang Zhe Chong Wan 大黄䗪虫丸 combines it with the insect blood-movers for exactly this picture — but a mass in the abdomen must be investigated by a physician before anything is prescribed for it.
- Kills intestinal parasitesRecorded in the classics for parasitic abdominal pain. Parasitic infection today is diagnosed by testing and treated with established antiparasitic medicines; this entry records the traditional indication rather than proposing the herb for it.
In Formulas
Formulas containing Gan Qi
Indications & Clinical Uses
- Amenorrhoea from long-standing blood stasis, with fixed stabbing pain
- Fixed, palpable abdominal masses (after medical investigation)
- Parasitic abdominal pain, in the classical record only
Western Medical Keywords
Searchable condition terms
Contraindications
Cautions
Gan Qi is toxic, it is contraindicated in pregnancy, and it causes severe allergic skin reactions in sensitised people.
- Contraindicated in pregnancy. It breaks blood and disperses masses; this is exactly the action that endangers a pregnancy. Avoid while breastfeeding as well.
- Contact allergy is the practical danger. Lacquer sap contains urushiol, the allergen of poison ivy and poison oak. In a sensitised person contact produces intense itching, redness, swelling and blistering — in the classical literature — typically on the hands, forearms and face, appearing a day or two after exposure and lasting one to three weeks. Sensitisation is usually permanent once it happens. People allergic to poison ivy, poison oak, mango skin or cashew shell are cross-reactive and should not handle this herb at all.
- The fumes matter too. Urushiol carries in the smoke and vapour given off while lacquer is being burned or calcined, and dermatitis and airway irritation have followed exposure to the fumes alone without touching the material. Processing belongs to a properly equipped pharmacy, never a kitchen.
- Calcining is mandatory. Raw lacquer is not taken internally. The herb is roasted or calcined until it no longer smokes, which removes the volatile irritant fraction; this is the only form with an internal dose.
- Internal reactions. Overdose or an allergic response after swallowing it can cause mouth and throat irritation, nausea, vomiting, abdominal pain and diarrhoea, and in some people a widespread itching rash. Stop and seek medical attention.
- Who else must avoid it. Anyone with no real blood stasis, anyone depleted or with weak digestion, anyone with a bleeding tendency or on anticoagulant medication, and anyone with a known lacquer or urushiol allergy.
- Watch for it in antiques and workshops, not only in the pharmacy: the same allergy is triggered by unhardened lacquer on furniture and craftwork.
Contraindicated in pregnancy: Contraindicated in pregnancy. Gan Qi breaks blood stasis and disperses accumulation forcefully, which risks the pregnancy directly. Avoid while breastfeeding; its safety in nursing has not been established and the allergic potential adds a second reason.
For licensed practitioners’ reference only
References
- Shen Nong Ben Cao Jing《神农本草经》(classical source, public domain).
2. Jin Gui Yao Lue《金匮要略》— Da Huang Zhe Chong Wan (classical source, public domain).
3. Bensky, Clavey & Stöger. Chinese Herbal Medicine: Materia Medica, 3rd ed.
4. 《中华人民共和国药典》— 2–5 g, calcined, in pills and powders; 孕妇禁用.
5. Urushiol, the allergen of lacquer sap, is the same contact allergen found in poison ivy and poison oak, and cross-reacts with mango skin and cashew shell oil; standard dermatology references describe the reaction.
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.