Yuan Hua
StarDaphne genkwa Sieb. et Zucc.
Traditionally used for
- Cough & breathing
- Urinary & fluids
- Skin
Cautions & contraindications
- Pregnancy
- Kidney conditions
- Toxic — professional use only
☯ TCM Properties
Drains Water and Expels Phlegm-Fluids; Expels Phlegm and Stops Cough; Kills Parasites and Resolves Toxicity
Traditional Chinese Uses
Yuan Hua (lilac daphne flower bud) is a warm, toxic herb that drains water from body cavities and expels Phlegm. It is used for severe fluid accumulation in the chest and abdomen — similar to Gan Sui and Jing Da Ji — and for Phlegm obstruction causing edema and respiratory difficulty. It is also used topically for scabies and other parasitic skin conditions. Due to its toxicity, it requires strict professional supervision, careful dosing, and processing to reduce harm. It is contraindicated with licorice root.
Relationships
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Botanical Description
Daphne genkwa Siebold & Zucc. (Thymelaeaceae) is a deciduous shrub 0.3-1 m tall native to China and Korea, with slender erect branches bearing opposite or sub-opposite oblong-lanceolate leaves and producing dense clusters of fragrant, lilac to violet four-lobed salverform flowers along the previous year's wood before the leaves emerge in spring. The unopened or just-opened flower buds are harvested in early spring, gently dried in the shade, and traditionally processed with vinegar before use. In TCM, Yuan Hua is acrid and bitter in flavor, warm in nature, and toxic, entering the Lung, Spleen, and Kidney channels; it drives out water accumulation, eliminates phlegm, and is used externally to kill parasites and treat skin lesions.
Active Constituents
Yuanhuacin (yuanhuacine)
Daphnane-type diterpene orthoesterConcentration: yields of roughly 9 mg per kg of dried flower buds are reported, and vinegar processing markedly lowers its content
The signature diterpene of Genkwa Flos and the compound behind its historical use as an abortifacient — yuanhuacin films were used for menstrual induction and termination of early pregnancy in China in the 1980s and 1990s, a practice since abandoned. It acts on the phorbol ester binding site of protein kinase C. Daphnane orthoesters of this class are severe skin and mucosal irritants and are the reason the whole drug is classed as toxic and absolutely contraindicated in pregnancy.
Yuanhuadin
Daphnane-type diterpene orthoesterA close congener of yuanhuacin with antiproliferative activity in lung cancer cell models. Like the rest of the series it is a potent irritant.
Yuanhuapin
Daphnane-type diterpene orthoesterAn extremely potent protein kinase C ligand (Ki in the sub-nanomolar range) and, per published review, probably the most toxic member of the yuanhua diterpene series, particularly damaging to the liver and the digestive tract.
Genkwadaphnin
Daphnane-type diterpene orthoesterA cytotoxic daphnane diterpene of the flower bud whose content, like yuanhuacin's, is reduced by vinegar processing.
Genkwanin
Methylated flavoneThe namesake flavone of the species and one of the main flavonoid constituents of the flower bud. The flavonoid fraction is anti-inflammatory, antioxidant and analgesic in animal models and is relatively enriched after vinegar processing as the diterpenes are reduced.
Apigenin
FlavonePresent free and as 7-O-glucuronide and 5-O-glucoside. Contributes to the anti-inflammatory and antioxidant activity of the flavonoid fraction.
Hydroxygenkwanin
Methylated flavoneA genkwanin analogue of the flower bud with reported osteoprotective and SIRT1-activating activity in preclinical models.
Luteolin
FlavoneA common flavone of the flower bud contributing to antioxidant activity; luteolin 7-methyl ether is reported alongside it.
Daphnoretin
BiscoumarinA dimeric coumarin isolated from the flower buds. Coumarins together with the flavonoids account for a large part of the non-diterpene pharmacology of the drug, including anti-complement activity.
⚠ Drug Interactions
Licorice / Gan Cao (Glycyrrhiza uralensis, G. glabra) and glycyrrhizin-containing preparations
This is the classical 'eighteen incompatibilities' pairing, and it is one of the few traditional incompatibilities with experimental support. Rodent studies of the licorice-yuanhua pair show ileum injury through weakened epithelial and mucous barrier function, with saponins, flavonoids and diterpenes all contributing; a separate biochemical, histopathological and metabonomic assessment confirmed the incompatibility of Genkwa Flos with Glycyrrhizae Radix et Rhizoma; and mass-spectrometry work with self-assembled supramolecular analysis has proposed a physicochemical basis for licorice enhancing Genkwa toxicity, including disturbance of colonic hydrogen sulfide metabolism. The Chinese Pharmacopoeia formally states that Yuan Hua should not be used together with Gan Cao.
Clinical note: Never combine. Because Gan Cao appears in a very large share of Chinese formulas, check every co-prescribed formula and every patent medicine for licorice before dispensing Yuan Hua, and check for glycyrrhizin in confectionery and licorice-flavoured products as well.
Hepatotoxic and nephrotoxic drugs (paracetamol/acetaminophen, NSAIDs, aminoglycosides, methotrexate)
Genkwa Flos exhibits significant hepato-nephrotoxicity, with yuanhuapin and yuanhuafin identified in review as the most damaging members of the diterpene series. Combining it with a drug that is itself hepatotoxic or nephrotoxic stacks injury on the same two target organs.
Clinical note: Avoid the combination. If Yuan Hua is used at all, use the vinegar-processed form, keep to the pharmacopoeial dose (1.5-3 g in decoction, or 0.6-0.9 g of powder once daily), limit to short courses, and check renal and hepatic function.
Digoxin and other cardiac glycosides
Yuan Hua is a harsh cathartic used to drive out water and phlegm-fluids, and it produces profuse watery stools. Purgative potassium loss is a well-established precipitant of digoxin toxicity. No case report ties Yuan Hua specifically to digoxin toxicity, so this is mechanistic reasoning from the herb's known cathartic action rather than observed events.
Clinical note: Avoid in digitalised patients. If a water-draining strategy is unavoidable, check potassium before and during treatment.
Loop and thiazide diuretics
The herb's cathartic water loss adds to pharmacological diuresis. This follows directly from the mechanism of both agents; it has not been quantified in a clinical study.
Clinical note: Monitor electrolytes, blood pressure and renal function if the combination cannot be avoided, particularly in the elderly and in ascites.
Lithium
Any agent causing substantial fluid loss can raise lithium concentrations by reducing renal clearance. Applied here from the herb's cathartic profile; no Yuan Hua-specific data exist.
Clinical note: Avoid in lithium-treated patients; if unavoidable, monitor lithium levels.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 1.5–3 g | — | — | — | ChP 2025. Vinegar-processed Yuan Hua taken as a powder, 0.6–0.9 g once daily. Contraindicated in pregnancy; NOT combined with Gan Cao. Corrected from a generic 6-15g decoction filler value generated from tcm_category. |
| topical | Appropriate amount | — | — | — | ChP 2025. 外用适量。 |
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
Two harsh water-expelling herbs used together to drive out pooled fluid in the chest and hypochondrium.
Suspended fluid (xuan yin) and severe edema in robust patients. Toxic, drastic purgative; for robust patients only, stop once effect is achieved, contraindicated in pregnancy. Both are incompatible with Gan Cao (eighteen incompatibilities).
Core pair of a classical formula — Shi Zao Tang, Shang Han Lun (Zhang Zhongjing)
Evidence Tier
Limited evidence · 2 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
0
In vitro / animal
2
1 verified · 1 unverified
Show 2 studies
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Licorice-Yuanhua Herbal Pair Induces Ileum Injuries Through Weakening Epithelial and Mucous Barrier Functions: Saponins, Flavonoids, and Di-Terpenes All Involved
Showed in rodents that combining licorice with Yuanhua damages the ileum by weakening epithelial and mucous barrier function, and that saponins, flavonoids and diterpenes all contribute. Provides experimental support for the classical eighteen-incompatibilities prohibition on this pair.
Incompatibility assessment of Genkwa Flos and Glycyrrhizae Radix et Rhizoma with biochemical, histopathological and metabonomic approach
Assessed the Genkwa Flos and licorice combination using biochemistry, histopathology and metabonomics, confirming that co-administration worsens toxicity relative to Genkwa Flos alone.
⚠ Safety & Contraindications
- Pregnancy
- Kidney conditions
- Toxic — professional use only
Contraindications
Contraindicated in pregnancy — it is a documented abortifacient — and in the weak or depleted.
Safety Warnings
- Processed with vinegar to moderate the toxicity before use.
- Incompatible with Gan Cao under the classical eighteen incompatibilities.
⚠ 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)
- 十八反: Gan Cao × Yuan Hua — avoid combining with Gan Cao / Glycyrrhiza / Licorice
Pregnancy
Avoid toxic purgative
⚠ Toxicity Information
Violent purgation, abdominal pain, vomiting, dehydration; the drug is abortifacient and irritant to skin and mucosa.
Historical Texts
Shen Nong Ben Cao Jing
Han dynastyShang Han Lun
Han dynastyChinese Pharmacopoeia (Zhonghua Renmin Gongheguo Yaodian)
Modern, 2020 editionReferences
- Hu Y, Pan R, Wang Y, Ma M, Peng Y, Fan W, Zhang R, Nian H, Zhu J. Daphne genkwa: Ethnopharmacology, phytochemistry and pharmacology of an important traditional Chinese medicine . Fitoterapia (2024) [DOI]
- Bailly C. Yuanhuacin and Related Anti-Inflammatory and Anticancer Daphnane Diterpenes from Genkwa Flos—An Overview . Biomolecules (2022) [DOI]
- Yang Y, Li F, Yan M, Chen S, Cai D, Liu X, Han N, Yuan Z, Lu J, Zhang Y, Ma Q, Wang P, Lei H. Revealing the Toxicity-Enhancing Essence of Glycyrrhiza on Genkwa Flos Based on Ultra-high-performance Liquid Chromatography Coupled With Quadrupole-Orbitrap High-Resolution Mass Spectrometry and Self-Assembled Supramolecular Technology . Frontiers in Chemistry (2021) [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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