Long Gu (Fossilized Mammal Bones)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Long Gu, and how is it prepared?

  15–30 g in decoction, cooked first — added 20–30 minutes before the other herbs because it is a dense fossil substance. Use raw (unprocessed) to calm the spirit and anchor yang; use calcined to astringe leakage of fluids.

  Source: owner’s Five Branches notes (5–10 qian, ≈15–30 g; “cook 20–30 minutes before; raw to calm spirit, calcined to astringe leakage”); standard materia medica ranges. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions or contraindications for Long Gu?

  Long Gu is contraindicated in damp-heat and in exterior excess patterns. As a dense mineral/fossil substance it can injure Stomach qi, so it is used with care — and not long-term — in weak digestion, where it may cause indigestion or loss of appetite.

  Source: owner’s Five Branches notes (contraindications; general caution for anchor/settle minerals and shells).

Chinese Herb Toxicity & Overdose

• Low for authentic material. Genuine Long Gu is a fossilized mammalian bone (carbonated hydroxyapatite) with no significant toxicity reported at normal doses. However, because it is a depleting fossil resource, the market carries adulterants — including fluoride-rich dinosaur fossils and processed modern bones — and pharmacopoeial standards have focused only on calcium content, so authenticated sourcing and contaminant screening bear directly on safety.

  Source: PMID 41672119 (Long Gu review: fossilized mammalian bioapatite; market adulteration and call for stricter safety monitoring). Neutral sourcing-quality note.

Herb-Drug Interactions

• No well-established clinical herb–drug interactions are documented. Long Gu is chiefly carbonated hydroxyapatite (a calcium-phosphate mineral); a theoretical potential exists for mineral binding to reduce absorption of certain co-administered drugs, so spacing is a reasonable practitioner precaution. (Flagged for practitioner confirmation — theoretical, not a documented interaction.)

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 Long Gu (dragon bone)?

  It is limited and mostly about identity, chemistry and sourcing rather than efficacy. A 2026 review confirms Long Gu is fossilized ancient mammalian bone — correctly identified by Li Shizhen in the Ming dynasty — and is chemically carbonated hydroxyapatite (not calcium carbonate), with high porosity and a trace-element profile (Zn, Sr); it flags resource depletion and widespread adulteration and calls for stricter quality and safety standards. A taxonomic study of 20,939 market fossil fragments (nearly all mammalian) — Long Gu being the only fossil crude drug in the Japanese Pharmacopoeia — supports developing sustainable substitutes. At the formula level, Chaihu-Longgu-Muli Decoction (Shanghan Lun) has been studied preclinically for insomnia–depression comorbidity, and an equivalence RCT supported replacing Os Draconis with oyster shell in a pediatric formula.

  Note: Long Gu appears in the literature under two pharmaceutical names — Os Draconis (Sacred Lotus sources & references) and Fossilia Ossis Mastodi (used in the Japanese Pharmacopoeia). These are the same fossilized-mammal-bone substance, not a genuine disagreement.

  Sources: PMID 41672119 (textual research, modern evaluation & quality-control challenges); PMID 28220276 (taxonomic examination of longgu / Fossilia Ossis Mastodi and longchi); PMID 42309270 (Chaihu-Longgu-Muli Decoction, preclinical); PMID 40350957 (equivalence RCT supporting oyster-shell substitution). Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Long Gu different from Mu Li, and what is it combined with?

  Both Long Gu and Mu Li are heavy shell/mineral substances that anchor yang, calm the spirit and astringe, and the pair is classically used together to strengthen anchoring. Long Gu is the more effective, more direct spirit-calmer; Mu Li additionally softens hardness and dissipates nodules and benefits yin and absorbs stomach acid.

  Differentiation and pairings:

  • vs Mu Li — Long Gu calms the spirit more strongly; Mu Li adds softening-hardness/dissipating-nodules and benefits yin. Combined, they enhance anchoring of yang.
  • vs Long Chi (dragon tooth) — a related fossil (Dens Draconis) with stronger spirit-calming action, favored for marked irritability, insomnia and disturbed dreaming.
  • With Mu Li — the classic anchoring pair, e.g. in Gui Zhi Jia Long Gu Mu Li Tang, Chai Hu Jia Long Gu Mu Li Tang, and Zhen Gan Xi Feng Tang.
  • With Suan Zao Ren & Shou Wu Teng (Ye Jiao Teng) — for insomnia with fright, nightmares and disturbed sleep.

  Source: owner’s Five Branches notes (comparative-functions & combination sets); standard materia medica formulas.