Lai Fu Zi
StarRaphanus sativus L.
Traditionally used for
- Cough & breathing
- Digestion
Cautions & contraindications
- Liver conditions
☯ TCM Properties
Reduces Food Stagnation and Eliminates Distension; Descends Qi and Transforms Phlegm; Descends Lung Qi and Stops Cough
Traditional Chinese Uses
Lai Fu Zi (radish seed) is a powerful Qi-regulating and food-dissolving herb that descends Stomach and Lung Qi. It is particularly effective for bloating, belching, and distension from undigested food, as well as for cough with profuse phlegm accompanied by chest fullness. Its descending action on Lung Qi gives it notable respiratory applications in addition to its digestive role. It is often combined with other digestive herbs in formulas for food stagnation and Phlegm-Damp patterns.
Western Herbalism Properties
Traditional Uses
The Costanoan of California used the raw stems of Raphanus sativus for food (Bocek 1984, Ethnobotany of Costanoan Indians, California, Based on Collections by John P. Harrington, Economic Botany 38(2):240-255, p. 252).
Relationships
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Botanical Description
Raphanus sativus L. (Brassicaceae) is an annual or biennial herb cultivated worldwide for its enlarged, fleshy taproot. The plant produces a basal rosette of pinnately lobed, lyrate leaves with a large terminal lobe, the foliage rough-hairy and 10 to 30 cm long. As the plant bolts, an erect, branched flowering stem 0.6 to 1.5 meters tall is produced, bearing alternate, smaller leaves and terminal racemes of four-petalled cruciform flowers in white, pale pink or purple, each about 1.5 to 2 cm across. The fruit is a distinctive indehiscent silique, swollen and somewhat constricted between the seeds, with a long beak; at maturity it is spongy-corky and contains several rounded, reddish-brown to grayish seeds about 3 mm across. The mature, dried seeds harvested in summer constitute Lai Fu Zi in Chinese medicine; the same species supplies common radish and the larger daikon as a vegetable.
Active Constituents
Sinapine (usually assayed as sinapine thiocyanate)
Choline ester of sinapic acid (alkaloid)The principal alkaloid of the seed and its main quality-control marker. Together with glucoraphenin it carries the blood-pressure and vascular-endothelial effects reported for radish seed, and sinapine thiocyanate has been studied for protection of inflamed vascular endothelium. All of that evidence is animal and cell-based.
Glucoraphenin (4-methylsulfinyl-3-butenyl glucosinolate)
GlucosinolateThe characteristic glucosinolate of radish seed and an inert storage form. Plant myrosinase, released when the seed is crushed, and the thioglucosidase activity of gut bacteria hydrolyse it to sulforaphene. This means the pharmacology of the drug depends on how it is prepared: crushing before decoction and the patient's own gut flora both change what is actually absorbed.
Sulforaphene (4-methylsulfinyl-3-butenyl isothiocyanate)
IsothiocyanateThe active hydrolysis product of glucoraphenin, historically described in the Chinese literature as raphanin. It is the antibacterial and antioxidant principle of the seed and the analogue of broccoli's sulforaphane. Isothiocyanates are electrophilic and gastric-irritant at high concentration, which is consistent with the traditional caution against Lai Fu Zi in weak, deficient patients.
Brassinosteroids
Plant steroid hormoneNamed in the review literature as one of the four major compound classes of Raphani Semen. Their contribution to any human effect of the drug is uncharacterised and should not be asserted.
Erucic acid and other seed-oil fatty acids
Long-chain monounsaturated fatty acidBrassicaceae seeds accumulate erucic acid in the fixed oil. This is a genuine consideration if a fatty extract or expressed seed oil is used rather than a decoction of the crushed seed, since dietary erucic acid intake is regulated in food oils; a conventional water decoction extracts very little of it.
Flavone glycosides, phenylpropanoid sucrosides and sulfur-containing derivatives
Mixed phenolic and organosulfur constituentsThe remaining characterised fraction of the seed, described across the phytochemical surveys of Raphanus sativus seeds. Individually they are not established as active, and none should be quoted as the drug's active principle.
⚠ Drug Interactions
Panax ginseng (Ren Shen) and other ginsenoside-containing qi tonics
This pairing needs to be recorded precisely, because it is usually mis-sourced. It is not in either classical incompatibility list: neither the Eighteen Antagonisms (Shi Ba Fan) nor the Nineteen Mutual Inhibitions (Shi Jiu Wei) contains ginseng with Lai Fu Zi, and the Shen Nong Ben Cao Jing, Ben Cao Jing Ji Zhu, Xin Xiu Ben Cao, Ben Cao Gang Mu and the Qing materia medica do not record the two as xiang wu. The prohibition as it is taught today entered through modern Chinese materia medica teaching - it is generally traced to the third edition of the standard Zhong Yao Xue textbook - and Chinese commentators have contested it on the ground that the classical statements concern the radish root (Lai Fu), not the seed. What does exist is a consistent modern experimental case: co-decocting the two lowers measured ginsenoside content; Semen Raphani increased the efflux of the six major ginsenosides (Rg1, Re, Rb1, Rb2, Rc, Rd) across Caco-2 monolayers, implying reduced intestinal absorption; Semen Raphani altered ginseng saponin composition and its hypothalamic-pituitary-adrenal axis regulation in rats; and it weakened ginseng's action under chronic fatigue conditions in vivo. The direction of the traditional claim is therefore supported pharmacokinetically, even though its classical pedigree is not what practitioners are usually told.
Clinical note: Do not put Lai Fu Zi and Ren Shen in the same formula where the point of the prescription is to tonify qi. Where both actions are genuinely needed - food stagnation in a deficient patient - separate the doses in time or use a gentler descending herb. Present this to patients and colleagues as a modern textbook rule with supporting pharmacokinetic evidence, not as a classical incompatibility.
Rehmannia glutinosa (Di Huang) and Polygonum multiflorum (He Shou Wu)
This is the incompatibility the classical texts actually record for this plant, and it is not the ginseng one. Ben Cao Gang Mu records that radish taken over time with Di Huang and He Shou Wu causes the beard and hair to turn white, the classical way of saying that the moving, descending radish disperses what those two herbs are given to accumulate. Modern Chinese clinical writing adds uncontrolled observations of rash when radish seed is combined with He Shou Wu and prepared Rehmannia. There is no pharmacological study of either claim, and the classical statement concerns the root rather than the seed, so this is recorded as traditional and theoretical - but a practitioner asked about a classical Lai Fu Zi incompatibility should be given this pair, not ginseng.
Clinical note: Note it when writing a nourishing formula containing Shu Di Huang or He Shou Wu that also needs a food-stagnation herb, and consider Shan Zha or Mai Ya instead. Be alert that a He Shou Wu containing formula carries its own hepatotoxicity risk independent of this interaction.
Antihypertensive drugs (ACE inhibitors, calcium channel blockers, thiazides)
Radish seed lowered systolic, diastolic and mean arterial pressure in prehypertensive rats, downregulating endothelin-1 and raising nitric oxide, and improved vascular endothelium in spontaneously hypertensive rats when combined with Uncaria. Radish seed extract has also been reported to depress cardiovascular parameters through muscarinic receptor activation. The drug is used in Chinese practice for hypertension on this basis. All the evidence is animal; there is no controlled human trial, so additive hypotension is plausible rather than demonstrated.
Clinical note: Check blood pressure when Lai Fu Zi is added at therapeutic dose to a patient already on antihypertensives, particularly the elderly and those prone to postural symptoms.
Levothyroxine and antithyroid therapy
Glucosinolate hydrolysis products from Brassicaceae include goitrogenic species that can inhibit iodine uptake. Radish seed is glucosinolate-rich, so the mechanism is present in principle. No case report or study has documented thyroid effects from medicinal Lai Fu Zi dosing, and the exposure from a decoction is far below the levels at which brassica goitrogenicity is described, so this is recorded as a mechanism to be aware of rather than an observed interaction.
Clinical note: No routine action needed. Consider it only in a patient with existing iodine deficiency or unstable thyroid replacement who is taking large amounts of Brassicaceae material long term.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 5–12 g | Daily | — | — | 中国药典 2020 【用法与用量】5～12g。 【性味与归经】辛、甘，平。归肺、脾、胃经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Dui Yao — Herb Pairs
The classical two-herb combinations this herb appears in, each with an action neither herb has alone.
Warms and disperses cold phlegm while descending qi and reducing food accumulation.
Core pair of a classical formula — San Zi Yang Qin Tang, Han Shi Yi Tong (Han Mao)
Reduce food accumulation while descending qi to relieve distention.
Food stagnation with abdominal distention.
Core pair of a classical formula — Bao He Wan, Dan Xi Xin Fa (Zhu Danxi)
Descends lung qi and transforms phlegm while reducing food stagnation, so that phlegm arising from stagnant food is cleared at its source.
Cough and wheezing with copious phlegm, chest oppression and poor appetite, especially in the elderly.
Core pair of a classical formula — San Zi Yang Qin Tang, Han Shi Yi Tong (Han Mao)
Evidence Tier
Moderate evidence · 6 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
6
0 verified · 6 unverified
Show 6 studies
- Impact of radish seeds (Semen Raphani) on the absorption and transportation of ginsenosides in the Caco-2 cell model: a UPLC-ESI-MS analysis
- Semen raphani weakened the action of ginseng under chronic fatigue condition
- Studies on antagonism effect of Semen raphani on Panax ginseng from saponin composition and hypothalamic-pituitary-adrenal axis regulation effect
- Effects of Raphani Semen on anti-fatigue and pharmacokinetics of Panax ginseng
- Decompression Mechanism of Radish Seed in Prehypertension Rats through Integration of Transcriptomics and Metabolomics Methods
- Enhanced Protective Effect of the Combination of Uncaria and Semen Raphani on Vascular Endothelium in Spontaneously Hypertensive Rats
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
Impact of radish seeds (Semen Raphani) on the absorption and transportation of ginsenosides in the Caco-2 cell model: a UPLC-ESI-MS analysis
Quantified six ginsenosides (Rg1, Re, Rb1, Rb2, Rc, Rd) crossing Caco-2 monolayers with and without Semen Raphani. Radish seed increased ginsenoside efflux, more so at higher concentrations, implying reduced intestinal absorption. This is the most direct mechanistic evidence for the ginseng antagonism and it used Raphanus sativus seed, not the root.
Semen raphani weakened the action of ginseng under chronic fatigue condition
In a chronic fatigue model, co-administered Semen Raphani reduced the benefit obtained from ginseng, giving an in vivo functional counterpart to the absorption findings. Animal study; it tests the traditional claim directly rather than by inference.
Studies on antagonism effect of Semen raphani on Panax ginseng from saponin composition and hypothalamic-pituitary-adrenal axis regulation effect
Combined saponin profiling with an in vivo endpoint, reporting that Semen Raphani alters the ginsenoside composition of the co-decoction and blunts ginseng's regulation of the hypothalamic-pituitary-adrenal axis. Supports both a chemical and a functional route for the antagonism.
Effects of Raphani Semen on anti-fatigue and pharmacokinetics of Panax ginseng
Reported that Raphani Semen reduced ginseng's anti-fatigue effect and altered ginsenoside pharmacokinetics in animals. Not retracted, but a corrigendum to this paper was published by the same authors in 2021 (doi 10.1016/j.chmed.2021.04.005), so the corrected version should be read rather than the original.
Decompression Mechanism of Radish Seed in Prehypertension Rats through Integration of Transcriptomics and Metabolomics Methods
Radish seed lowered systolic, diastolic and mean arterial pressure in prehypertensive rats, with transcriptomic and metabolomic changes and evidence of reduced endothelin-1 and increased nitric oxide. Animal study; it is the basis of the Chinese use of Lai Fu Zi for hypertension, an indication the standard Western TCM materia medica does not list.
Enhanced Protective Effect of the Combination of Uncaria and Semen Raphani on Vascular Endothelium in Spontaneously Hypertensive Rats
Semen Raphani combined with Uncaria improved vascular endothelial measures in spontaneously hypertensive rats beyond either alone. Supports a vascular rather than diuretic mechanism for the hypotensive effect, but studies the pair rather than radish seed alone.
Historical Texts
Ri Hua Zi Ben Cao
Five DynastiesBen Cao Yan Yi Bu Yi
Yuan dynastyBen Cao Gang Mu
Ming dynastyReferences
- Gao Lei; Li Huan; Li Bingqian; Shao Huili; Yu Xinyue; Miao Zhuang; Zhang Lizhen; Zhu Liqiao; Sheng Huagang. Traditional uses, phytochemistry, transformation of ingredients and pharmacology of the dried seeds of Raphanus sativus L. (Raphani Semen), A comprehensive review . Journal of Ethnopharmacology (2022) [DOI]
- Sham Tung-Ting; Yuen Ailsa Chui-Ying; Ng Yam-Fung; Chan Chi-On; Mok Daniel Kam-Wah; Chan Shun-Wan. A Review of the Phytochemistry and Pharmacological Activities of Raphani Semen . Evidence-Based Complementary and Alternative Medicine (2013) [DOI]
- Dong Meiyue; Tian Zhenhua; Zhou Qian; Liu Yuhong; Wang Xiaoming; Ren Wenjing; Li Yunlun; Jiang Haiqiang. Chemical constituents from the seeds of Raphanus sativus L. and their chemotaxonomic significance . Biochemical Systematics and Ecology (2020) [DOI]
- Kim Ki Hyun; Moon Eunjung; Lee Seoung Rak; Park Kyoung Jin; Kim Sun Yeou; Choi Sang Un; Lee Kang Ro. Chemical Constituents of the Seeds of Raphanus sativus and their Biological Activity . Journal of the Brazilian Chemical Society (2015) [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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