Hai Jin Sha (Spores of Japanese Fern)

Chinese Herb Actions

Chinese Herb Dosage

• Why is Hai Jin Sha decocted wrapped, and what is the dosage?

  Hai Jin Sha must be decocted wrapped in cloth (bao jian, 包煩) — typically 6–15 g. The reason is physical: the medicinal is not a root or leaf but a mass of fern spores, each one microscopic, so the material behaves like a fine dust. Loose in the pot it floats on the surface, clumps, and then passes straight through a strainer into the finished decoction. Tying it into a thin cotton, muslin or cheesecloth bag lets water extract it normally while keeping the powder contained.

  • Why the weights look small — 6–15 g of spores is a surprisingly large volume of material, because spores are extremely light. A dose that would be modest for a root fills a considerable scoop here.
  • Same instruction, different reason — this is the same wrapped-decoction handling used for Xuan Fu Hua, though for a different cause: Xuan Fu Hua is wrapped because its fine hairs irritate the throat, while Hai Jin Sha is wrapped because the spores are too fine to strain out. Can Sha is wrapped for the same practical reason as Hai Jin Sha.
  • Powder form — because it is already a powder, it is also traditionally taken directly in small amounts stirred into liquid rather than decocted.

  Source: our own herb record (dosage figures as held, and the wrapping instruction) and standard materia medica ranges (Bensky et al., 3rd ed.; Chen & Chen), cross-referenced against multiple online sources. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Hai Jin Sha?

  Hai Jin Sha is a cold, draining herb, so the cautions recorded in our own data are about draining someone who has nothing to spare — it is not used in true yin deficiency, and it is not used where there are no damp-heat signs to justify it. Draining herbs used against a deficiency picture are held to deplete fluids further.

  • True yin deficiency — contraindicated per our record.
  • No damp-heat present — our record states it should not be used where damp-heat signs are absent; the herb is pattern-specific rather than a general diuretic.
  • Urinary stones are a medical condition — stones and blood in the urine require diagnosis and management by a physician. This entry documents a traditional herb; it is not guidance for treating stones.
  • Pregnancy — no specific contraindication is recorded in our data; as with any cold, draining herb, use during pregnancy should be under a qualified practitioner.

  Source: our own herb record; category cautions per published materia medica consensus (Bensky et al., 3rd ed.), cross-referenced against multiple online sources. Reference note, not a safety guarantee.

Chinese Herb Toxicity & Overdose

• No toxicity is recorded for Hai Jin Sha in the materia medica, and it is not flagged as toxic in our own records. We were unable to locate any published toxicology study, poisoning report or dose-limiting safety data specific to Lygodium japonicum spores; the toxicity literature that exists under the genus name concerns other species (for example L. flexuosum and L. microphyllum), which we do not treat as transferable evidence. The absence of findings here reflects an absence of published investigation rather than a demonstration of safety.

  Source: our own herb record (not flagged toxic); materia medica consensus; PubMed literature search returned no species-specific toxicology for the spores. Reference note, not a safety guarantee.

Herb-Drug Interactions

• No herb–drug interactions have been documented for Hai Jin Sha. No clinical interaction studies exist for this material. As a precaution rather than a documented finding, any herb used for urinary complaints warrants practitioner awareness in patients taking diuretics or medicines cleared by the kidney. Patients should tell their prescriber what is in their formula. (Flagged for practitioner confirmation; reference information only.)

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 Hai Jin Sha (Lygodium japonicum)?

  Yes — and unusually, the research targets the same thing the tradition does: kidney stones. Two independent animal and laboratory studies report that extracts of this fern reduce calcium oxalate crystal formation. There are no human clinical trials.

  • Stone formation in rats — an ethanol extract of the spores (Lygodii spora) was tested in a rat model where stones are induced with ethylene glycol, in both preventive and therapeutic protocols at 400 mg/kg. The preventive protocol lowered urinary calcium, oxalate and uric acid and raised urinary citrate; both protocols reduced kidney peroxides, renal calcium and oxalate content, and the number of oxalate deposits in the kidney, compared with untreated stone-forming controls (PMID 24972555).
  • How it might work, at crystal level — a 2025 Phytomedicine study isolated a 12.9 kDa polysaccharide from L. japonicum and found it adsorbs to high-energy crystal faces of calcium oxalate monohydrate, reducing crystal size and pushing conversion toward the less adhesive dihydrate form, while inhibiting crystal adhesion and uptake by cells and reducing oxidative injury; in rats it accumulated in the kidney and reduced crystal formation (PMID 40318530).
  • Anti-inflammatory activity of the spores — ethanol extracts of the spores suppressed nitric oxide and TNF-α production in lipopolysaccharide-stimulated mouse macrophages at non-cytotoxic concentrations, through inhibition of NF-κB and p38 MAPK signalling (PMID 29067444). This is relevant background to the herb’s traditional use in hot, painful urination.
  • Wider context — a 2025 scoping review of medicinal plants studied for urolithiasis places this fern among the plants with antioxidant and anti-inflammatory activity investigated for stone disease (PMID 40648041).

  All of this is preclinical: cells, crystals and rats. It offers a coherent mechanistic story for a traditional indication, but it is not evidence that Hai Jin Sha dissolves or prevents kidney stones in people, and stone disease needs medical assessment.

  Sources: PMID 24972555 (DOI 10.1007/s00240-014-0674-z); PMID 40318530 (DOI 10.1016/j.phymed.2025.156734); PMID 29067444 (DOI 10.3892/mmr.2017.7070); PMID 40648041. Research context, not a therapeutic claim.

Chinese Herb Notes

• What part of the plant is Hai Jin Sha?

  Hai Jin Sha is the dried mature spores of the Japanese climbing fern, Lygodium japonicum — not the leaf, root or whole plant. The spores are shaken or beaten out of the fertile fronds and collected as a fine, free-flowing golden-brown powder. That appearance is exactly what the Chinese name records: the translation our record carries, “Sea Gold Sand,” describes a substance that pours and glints like fine sand.

  Using spores as the medicinal part is unusual, and it drives almost everything practical about the herb: the tiny apparent weights, the need to decoct it wrapped, and the fact that it is dispensed as a powder rather than as recognizable plant pieces. Ferns reproduce by spores rather than seeds, so this is the fern equivalent of a seed medicinal.

  Is Hai Jin Sha Teng the same herb?

  No — same fern, different part, and we hold both. The vine (the climbing stem and fronds of Lygodium japonicum) is met in the literature as Hai Jin Sha Teng and is catalogued in our materia medica under the name Jin Sha Teng. The pharmaceutical Latin is what makes the pair unambiguous: this entry is Spora Lygodii Japonici, the spores; the vine entry is Herba Lygodii Japonici, the aerial herb. One plant, two catalogued medicinals — so a reader who meets the vine name elsewhere should follow it to Jin Sha Teng, not to this page.

  How the two parts differ in our own data:

  • Nature and category — the spores are sweet and cool, filed under herbs that regulate water and drain dampness; the vine is sweet and cold, filed under herbs that clear heat and eliminate toxins, and it carries a fire-toxin action for mumps and hot swollen throat that the spores do not.
  • Dosage — the spores are given at roughly 6–15 g, the vine at 15–60 g. The gap is a difference in the bulk of the material, not in potency, and it is one reason the two are never interchangeable on a prescription.
  • Handling — the wrapped-decoction instruction (bao jian) belongs to the spores alone, because only they are a fine floating dust. The vine is chopped stem and frond and is decocted loose; a wrapping instruction attached to the vine is a sign the two parts have been confused. The vine is also used topically, which our spore record does not note.
  • What they share — both enter the same channel pair, Bladder and Small Intestine, and both clear damp-heat from the urinary tract. The vine is the broader and colder of the two; the spores are the narrower, stone-focused one.

  Identity field flagged, not altered. Our record gives the properties as “Sweet, Cool.” Standard modern references more commonly describe Hai Jin Sha as sweet and salty, cold. The channel entry (Bladder and Small Intestine) matches across sources. The difference is one of degree and of an additional flavour rather than a different substance; we have left the field unchanged and flag it for owner confirmation.

  What is Hai Jin Sha combined with?

  Hai Jin Sha does not appear in any formula we currently hold, so the combinations below are the classical pairings recorded in the reference literature rather than links from our own formula data:

  • With Jin Qian Cao (lysimachia) and Ji Nei Jin (chicken gizzard lining) — the standard grouping for urinary and biliary stones; all three are in our materia medica.
  • With Hua Shi (talcum), Che Qian Zi, Qu Mai and Bian Xu — for hot painful urinary dysfunction with burning and urgency.
  • With Shi Wei — for bloody painful urination.

  (Traditional combination context, not treatment advice.)

  Source: our own herb records for the spores and for the vine of the same fern, Jin Sha Teng (Latin names, categories, natures, channels and dosages, and the absence of formula links); botanical identification per PMID 24972555 and PMID 29067444; combinations per published materia medica consensus (Bensky et al., 3rd ed.), cross-referenced against multiple online sources.