Tan Xiang (Sandalwood (Heartwood))

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Tan Xiang?

  Roughly 1–5 g in decoction, depending on the source. Our record carries both standard figures: 1–3 g in decoction from Chen, and 2–5 g in decoction from Bensky. The overlap sits at 2–3 g, which is the practical working dose for most purposes. Smaller amounts are used when it is taken as a powder.

  • Decoction — 1–3 g (Chen) or 2–5 g (Bensky).
  • Preparation — added toward the end of cooking, as is standard for aromatic volatile herbs; long boiling wastes the fragrance that carries its action.
  • Powder — used at lower amounts than the decoction range, and it features in aromatic pill and powder formulas.

  Note: the two reference ranges differ (1–3 g vs 2–5 g). This is a normal difference of editorial convention between materia medica, not a factual conflict; both are reported rather than averaged.

  Source: our own herb record (both recorded ranges); published materia medica consensus. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Tan Xiang?

  Yes — it is warm and drying, so it is not suited to heat or yin-deficient patterns. Our record gives three cautions: do not use in patients with fire or yin-deficiency heat; do not use for vomiting caused by heat; and use with caution during pregnancy because of a possible abortifacient effect. As with all aromatic warming herbs, prolonged use can consume fluids.

  • Heat and yin deficiency — avoid; a warm aromatic will aggravate these patterns.
  • Heat-type vomiting — not indicated.
  • Pregnancy — caution, per our record; discuss with a qualified practitioner.
  • Sourcing (reference note) — Santalum album is a conservation-sensitive, heavily exploited species and its trade is regulated in its native range (see research). Buyers should expect provenance information, and should be sceptical of unusually cheap “sandalwood.” Our own record already carries this herb under its toxic/endangered marker on conservation grounds, not toxicity grounds.
  • Substitution (reference note) — commercial sandalwood oils have been shown to vary against the international standard (see research), and cheaper woods and oils are sold under the sandalwood name. Botanical source matters.

  Source: our own herb record (heat, yin-deficiency, pregnancy cautions and the endangered marker); published materia medica consensus; conservation and quality research below. Reference disclosures, not usage instructions.

Chinese Herb Toxicity & Overdose

• None noted in the traditional literature at normal doses, and our record carries no toxicity for it. Sandalwood heartwood has a long history of use as a medicinal, an incense and a fragrance material with no significant reported toxicity in ordinary use.

  Two clarifications worth making:

  • The endangered marker on this herb is not a toxicity marker. Our record flags Tan Xiang under its toxic/endangered field because of the conservation status of the source tree, not because the wood is poisonous.
  • Sandalwood oil is not the same product as the medicinal heartwood. Most modern safety and clinical literature concerns the distilled essential oil applied topically. Findings about the oil should not be read across to the decocted wood, nor the reverse.

  Source: our own herb record (“None noted”); published materia medica consensus. Reference note, not a safety guarantee.

Herb-Drug Interactions

• No well-established clinical herb–drug interactions are documented for Tan Xiang as used in decoction. The published human work concerns topically applied sandalwood oil rather than the ingested heartwood, and reports no systemic drug interaction. Standard practitioner caution applies to any aromatic herb used long-term or in a complex prescription. (No interaction claim is made here; 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 sandalwood (Santalum album) endangered?

  It is a documented conservation case: Santalum album was designated Vulnerable by the IUCN in 2019, and its wild populations have declined sharply. A 2024 genomic paper states directly that “the International Union for Conservation of Nature (IUCN) designated S. album as a ‘vulnerable (vu)’ species in 2019” (PMID 38481824; PMC 10928027). A 2025 review of the species’ genetic resources adds that India contributes more than 85% of global production while natural populations “have sharply declined due to overexploitation, habitat loss, and disease pressures” (PMID 41313490).

  • Why it is vulnerable — the tree is slow-growing, the valuable heartwood takes decades to form, and it is a root hemiparasite that needs host plants, all of which make wild populations slow to recover from harvesting.
  • Trade controls — harvesting and trade of S. album are restricted in India, its principal native range, under national and state law. Rules have changed repeatedly, so check the current regulation for your jurisdiction rather than relying on any summary. We do not assert a CITES appendix listing for this species; we could not verify one against a resolvable source, so no such claim is made.
  • Practical consequence — plantation-grown and certified material exists, and sourcing information is a fair thing to ask a supplier for.

  Is there modern research on Tan Xiang (Santalum album)?

  Yes — concentrated on the essential oil and its sesquiterpene alcohols, chiefly α-santalol, with early-stage clinical work in skin conditions rather than in the digestive or chest indications of Chinese medicine. None of it establishes the traditional uses.

  • Skin (early clinical) — interim results from a proof-of-concept phase 2 trial of topical East Indian sandalwood oil reported it was well tolerated and helped alleviate mild-to-moderate psoriasis symptoms, alongside laboratory work in reconstituted psoriatic skin models showing suppression of inflammatory mediators (PMID 28360856; PMC 5352686; DOI 10.3389/fphar.2017.00125). A small pilot study of a sandalwood-oil and turmeric cream reported reduced radiodermatitis in head-and-neck cancer patients undergoing radiotherapy (PMID 24694358; PMC 4075548). Both are small, topical, and preliminary.
  • Chemistry and mechanism — α-santalol and synthetic derivatives have been characterised as cannabinoid receptor type II ligands (PMID 37450763; PMC 11214301), and the biosynthesis of the santalols is well mapped, including reconstruction of the pathway in yeast (PMID 31940436).
  • Quality control — a comparison of selected commercial sandalwood oils against the international standard found variation between products (PMID 33924603; PMC 8070282), which is the analytical face of the substitution problem noted in the cautions.

  Important limitation: essentially all of this concerns the distilled essential oil applied to skin. The Chinese medicinal is the decocted or powdered heartwood taken internally for chest and epigastric patterns, and there is no clinical research supporting that use. The research is context on the plant, not evidence for the herb.

  Sources: PMID 38481824, PMC 10928027, DOI 10.1007/s13205-024-03952-5 (IUCN Vulnerable designation, 2019); PMID 41313490, DOI 10.1007/s10709-025-00251-6 (population decline; India >85% of production); PMID 28360856, PMC 5352686 (topical sandalwood oil, psoriasis, interim phase 2); PMID 24694358, PMC 4075548 (radiodermatitis pilot study); PMID 37450763, PMC 11214301 (α-santalol CB2 ligands); PMID 31940436 (santalol biosynthesis in yeast); PMID 33924603, PMC 8070282 (commercial sandalwood oils vs the international standard). Research context, not a therapeutic claim.

Chinese Herb Notes

• Is Tan Xiang the same as red sandalwood (Zi Tan)?

  No. Tan Xiang is white sandalwood, Santalum album. “Red sandalwood” — Zi Tan, from Pterocarpus species — is an unrelated tree in a different family and is a different medicinal entirely. They share an English word and nothing else botanically. Our own herb records hold no Zi Tan entry, so anything you read about “red sandalwood” is not describing this page’s herb.

  Also distinct: Australian sandalwood, Santalum spicatum, is a real sandalwood in the same genus but a different species, with a different oil profile. It is a legitimate commercial sandalwood but is not what the Chinese materia medica means by Tan Xiang — which specifies Santalum album, the Indian or East Indian sandalwood.

  Which formulas contain Tan Xiang?

  In our own formula records Tan Xiang appears in Dan Shen Yin (Salvia Decoction), Su He Xiang Wan (Liquid Styrax Pill) and Hui Chun Dan (Return of Spring Special Pill). Dan Shen Yin is the clearest illustration of its role — a small aromatic qi-mover placed alongside blood-invigorating herbs for pain in the chest and epigastrium, so that qi moves while the blood is moved. In Su He Xiang Wan it sits among the aromatic substances of an orifice-opening formula.

  How does Tan Xiang compare with other qi-regulating herbs?

  • Tan Xiang — aromatic and warming, directed at the chest and epigastrium; the choice where cold and qi constraint present together with chest or upper-abdominal pain.
  • Other qi-regulators in the same category generally target the Liver, the Spleen and Stomach broadly, or the lower abdomen. Tan Xiang’s distinguishing feature is its upper-body and chest orientation together with its fragrance.

  Source: our own herb and formula records (Dan Shen Yin, Su He Xiang Wan, Hui Chun Dan); published materia medica consensus for the comparisons; botanical distinction confirmed against the research sources cited below. Traditional formula context, not treatment advice.

This herb is from an endangered/protected species and is illegal in the United States