Lai Fu Zi (Daikon, Radish Seed)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Lai Fu Zi?

  Roughly 5–10 g in decoction, using the dried, ripe seed, conventionally crushed before decocting to release its active constituents. Some sources distinguish raw Lai Fu Zi, considered better at descending qi and transforming phlegm, from stir-fried (dry-fried) Lai Fu Zi, considered better at reducing food stagnation — a common processing distinction for this herb.

  Source: Sacred Lotus sources & references, cross-referenced against multiple online sources (standard materia medica dosage ranges and processing notes). Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Lai Fu Zi?

  Lai Fu Zi is traditionally avoided in patients without genuine food stagnation, or where Qi or Blood deficiency predominates — since its qi-breaking, downward-moving action can worsen an underlying deficiency rather than help it. Materia medica sources also advise caution in cases of nausea, and note that long-term use should be approached carefully rather than as an ongoing daily habit.

  • Not for deficiency patterns — avoid where Qi or Blood deficiency is the primary issue rather than food stagnation.
  • Ren Shen combining rule — traditionally not combined with Ren Shen, which it is said to antagonize (see Notes).

  Source: Sacred Lotus sources & references, cross-referenced against multiple online sources (materia medica cautions). Traditional-use framing; not medical advice.

Chinese Herb Toxicity & Overdose

• Insignificant. Lai Fu Zi is the seed of the common daikon/radish plant (Raphanus sativus), a widely eaten food crop, and no significant toxicity is reported at standard medicinal decoction doses in the materia medica literature or in the pharmacological studies reviewed below.

  Source: Sacred Lotus sources & references; PMID 34118598, PMID 16259783 (animal studies using radish seed extract at experimental doses without reported toxicity). Reference note, not a safety guarantee.

Herb-Drug Interactions

• No well-established clinical herb–drug interactions are documented for Lai Fu Zi. The one long-recognized interaction is the traditional herb-herb combining rule against pairing it with Ren Shen (see Notes), rather than a pharmaceutical drug interaction. Given preclinical evidence of gastrointestinal prokinetic (motility-promoting) activity (below), practitioner awareness is reasonable for patients on other GI-motility-affecting medications. (Flagged for practitioner confirmation.)

Western / Biomedical Research

Chinese Herb Clinical Studies & Research

Provided as research context — a summary of published biomedical study, not a therapeutic or medical claim.

• Is there modern research on Lai Fu Zi (Raphanus sativus seed)?

  Yes — multiple pharmacological studies support a genuine gastrointestinal prokinetic (motility-promoting) effect, consistent with its traditional food-stagnation-relieving and qi-descending use, though the evidence is preclinical (animal and isolated-tissue studies) rather than human clinical trials.

  • Species-dependent gut-stimulatory effects (2005) — a pharmacological study of radish seed extract found spasmogenic (contraction-stimulating) effects in isolated rabbit jejunum/ileum, rat stomach fundus/ileum, and guinea-pig ileum/jejunum, with the strongest effect in guinea-pig tissue; in rabbits and rats the effect was blocked by atropine (indicating a muscarinic-receptor mechanism), while the guinea-pig response used a different, atropine-resistant pathway. In live mice, the extract produced atropine-sensitive gastrointestinal prokinetic and laxative effects, and was non-lethal up to 10 g/kg over 24 hours. Preclinical pharmacology, not a clinical trial.
  • Intestinal motility in a high-calorie-diet model (2021) — a study in young rats fed a short-term high-calorie diet found that Raphanus sativus seed treatment normalized several motility-related markers that the high-calorie diet had disrupted — raising reduced serum substance P and ghrelin levels back up, lowering elevated nitric oxide, and increasing intestinal Cx43 and BDNF protein expression — supporting a role in regulating gut-motility hormone secretion and gut-wall protein expression. Animal-model evidence, not a human clinical trial.
  • Gallbladder contractile activity — separate pharmacological work on radish extracts has also reported contractile effects on isolated gallbladder tissue, a further preclinical data point consistent with a broader digestive-motility-modulating profile for the plant.

  Overall, the pharmacology literature offers reasonably consistent preclinical support for Lai Fu Zi’s traditional qi-descending, digestion-moving reputation; controlled human clinical trials specific to the seed have not been identified.

  Sources: PMID 16259783, DOI 10.1211/jpp.57.11.0016 (J Pharm Pharmacol, 2005, species differences in gut-stimulatory effects); PMID 34118598, DOI 10.1016/j.biopha.2021.111705 (Biomed Pharmacother, 2021, intestinal motility in high-calorie-diet rats); PMID 22499720 (gallbladder contractile effect, J Complement Integr Med, 2012). Research context, not a therapeutic claim.

Chinese Herb Notes

• What formulas is Lai Fu Zi found in, and why is it not combined with Ren Shen?

  Lai Fu Zi is best known as a core ingredient of Bao He Wan, the classic formula for food stagnation, and of San Zi Yang Qin Tang, where it works alongside two other seeds to descend qi and transform phlegm. It also carries a well-known classical caution: it is traditionally held to counteract (antagonize) the tonifying effect of Ren Shen (ginseng).

  • Bao He Wan (Preserve Harmony Pill) — Lai Fu Zi is combined with Shan Zha, Shen Qu, Ban Xia, Chen Pi, Fu Ling, and Lian Qiao to reduce food stagnation of mixed origin (meat, starch, and general overeating) with fullness, distension, belching, and acid regurgitation. (See the Bao He Wan formula entry.)
  • San Zi Yang Qin Tang (Three Seed Decoction to Nourish One’s Parents) — Lai Fu Zi is combined with Bai Jie Zi and Zi Su Zi (the “three seeds”) to descend qi, transform phlegm, and relieve cough and wheezing with copious sputum in an older or weaker patient, adjusting the ratio of the three seeds to the dominant symptom. (See the San Zi Yang Qin Tang formula entry.)

  The Ren Shen caution: Lai Fu Zi is traditionally described as breaking or reducing qi, which stands in direct opposition to Ren Shen’s qi-tonifying action; classical and modern materia medica sources commonly repeat the combining rule that Lai Fu Zi should not be used together with Ren Shen, since it is said to counteract (or at least substantially blunt) Ren Shen’s tonifying benefit. This is a well-known combining convention in practice, distinct from the formally codified “Eighteen Incompatibilities” and “Nineteen Antagonisms” lists, and practitioners weigh it when Lai Fu Zi and Ren Shen might otherwise appear in the same prescription. (Traditional formula/combining context, not treatment advice.)

  Source: Sacred Lotus sources & references (Bao He Wan and San Zi Yang Qin Tang formula links; classical Ren Shen combining rule), cross-referenced against multiple online sources.