Gu Sui Bu (Drynaria Rhizome)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Gu Sui Bu?

  3–9 g in decoction (traditional notes give roughly 6–15 g). For traumatic injury and hair loss it is also used externally — crushed and soaked in wine or alcohol, then applied to the affected area.

  Source: owner’s Five Branches notes (2–5 qian; external use in wine); standard materia medica ranges. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions or contraindications for Gu Sui Bu?

  Avoid or use with care in Yin deficiency with internal heat. As a warm, drying Kidney-yang tonic it can aggravate patterns of deficiency-heat. Traditional notes also caution against use where there is no blood stasis to move.

  Source: owner’s Five Branches notes (contraindications: Yin deficiency with internal heat; no blood stagnation).

Chinese Herb Toxicity & Overdose

• Low. No significant toxicity is reported at normal therapeutic doses; Drynaria rhizome is regarded as a well-tolerated tonic in the traditional literature and no notable toxicity signal appears in the reviewed pharmacology research.

  Source: materia medica consensus; no toxicity signal in the reviewed research. Research context, not a therapeutic claim.

Herb-Drug Interactions

• No well-established clinical herb–drug interactions are documented. A principal marker constituent of Drynaria is the flavonoid naringin; related flavonoids can influence drug-metabolizing enzymes in the laboratory, so practitioner caution is reasonable for patients on narrow-therapeutic-index medications. (Flagged for practitioner confirmation — absence of documented interactions is not proof of safety.)

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 Drynaria (Gu Sui Bu) for bone?

  Yes — bone is the most-studied area, though the evidence is preclinical. In a zebrafish model, Gu Sui Bu (Drynaria fortunei) counteracted glucocorticoid-induced loss of mineralization by modulating osteoblast and osteoclast activity. Total flavonoids of Drynaria promoted osteogenesis and cranial bone regeneration in laboratory models, and its marker flavonoid naringin reduced bone loss via Wnt/β-catenin signaling. Human clinical evidence remains limited.

  Sources: PubMed 35863613 (Gu Sui Bu vs glucocorticoid-induced mineralization reduction, zebrafish); PubMed 40069718 (total flavonoids, osteogenesis); PubMed 37778522 (cranial bone regeneration); PubMed 37831321 (naringin, Wnt/β-catenin, bone loss). Research context, not a therapeutic claim.

  Naming note: the source herb is commonly cited as Drynaria fortunei (the name used in our records and much of the literature); the currently accepted botanical name is Drynaria roosii Nakaike, with D. fortunei treated as a synonym. This is a botanical-naming variance, not a different herb.

Chinese Herb Notes

• How is Gu Sui Bu used and combined?

  Gu Sui Bu is the classic bone-and-sinew herb for trauma, working through the Kidney and Liver. Because the Kidneys govern the bones and the Liver governs the sinews, it both tonifies the root (Kidney deficiency with a weak back and knees) and treats the branch (recent fracture or sprain). It is a core ingredient in traumatology formulas for knitting broken bones and healing soft-tissue injury.

  How practitioners position it:

  • For fractures and trauma — combined with blood-invigorating and sinew-mending herbs in die-da (bone-setting) formulas.
  • For Kidney-deficient diarrhea — traditionally cooked with pork to tonify the Kidneys.
  • vs Xu Duan and Bu Gu Zhi — all strengthen the low back and knees; Gu Sui Bu is distinguished by its emphasis on mending injured bone and sinew.

  Common combinations: with Kidney-yang and essence tonics for weak, sore lower back and knees; with blood-invigorating herbs for fractures and sprains.

  Source: owner’s Five Branches notes (indications & combinations).