Su Mu
StarCaesalpinia sappan L.
Traditionally used for
- Digestion
- Menstrual & women's health
- Heart & circulation
Cautions & contraindications
- Pregnancy
- Bleeding disorders
☯ TCM Properties
Invigorates Blood and Dispels Stasis; Reduces Swelling and Alleviates Pain; Promotes Menstruation; Treats Traumatic Injuries
Traditional Chinese Uses
Su Mu (sappan wood) is a neutral, sweet-salty herb used in Chinese medicine to invigorate Blood and eliminate stasis, making it applicable for amenorrhea, menstrual pain, and postpartum abdominal pain from Blood stagnation. It also treats traumatic injuries with bruising and swelling and is used for certain types of chest pain from obstruction. While not as powerful as some other Blood-breaking herbs, its moderate action makes it appropriate for both excess and mixed deficiency-stasis patterns.
Relationships
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Botanical Description
Caesalpinia sappan (syn. Biancaea sappan), sappanwood, is a small to medium-sized thorny tree of the family Fabaceae, native to Southeast Asia and southern China and long cultivated for both medicine and dye. It grows 5 to 10 meters tall, with grayish bark and recurved prickles on the branches and along the rachis of the leaves. The leaves are bipinnately compound with numerous small oblong leaflets. Showy terminal panicles of bright yellow, slightly irregular flowers with a red blotch appear in summer, followed by flat, woody, oblong pods that contain three to four hard seeds. The dense, deep red to orange-red heartwood, rich in brazilein and homoisoflavonoid pigments, is the medicinal and dye material, harvested from mature trunks and split into chips.
Active Constituents
Brazilin
Homoisoflavonoid (isoindene-type)Concentration: about 1.26 g per 100 g of dried heartwood by HPLC in ethanolic extract studies; 8.7-22.2% w/w of brazilin-enriched extracts
Brazilin is the principal marker and the compound most of the pharmacology rests on. It induces heme oxygenase-1, relaxes rat aortic rings by both endothelium-dependent and endothelium-independent routes, and is antibacterial. Its effect on platelets is not the simple inhibition the herb's blood-moving reputation would predict: in washed human platelets brazilin behaves as a collagen-receptor agonist, potentiating collagen-induced aggregation at 1-10 micromolar and triggering aggregation directly at 20-50 micromolar.
Brazilein
Homoisoflavonoid (oxidation product of brazilin)The red oxidation product of brazilin and the reason sappan heartwood has been a dyewood for a thousand years. It forms readily on air exposure and in alkaline decoction, so the ratio of brazilin to brazilein in a finished decoction depends on how the wood was stored and prepared.
Protosappanin A
Dibenzoxocin (protosappanin-type phenolic)Protosappanins are a structural class largely confined to this drug and are, with the brazilin derivatives, treated as its defining chemistry. Protosappanin A is reported to contribute to the anti-inflammatory and immunomodulatory activity described for the heartwood.
Protosappanin B
Dibenzoxocin (protosappanin-type phenolic)A second major protosappanin of the heartwood, used alongside protosappanin A and brazilin in multi-marker quality control of Sappan Lignum.
Sappanchalcone
ChalconeOne of the chalcones of the heartwood, reported for anti-inflammatory activity mediated through NF-kappaB and Nrf2 signalling.
3-Deoxysappanchalcone
ChalconeUnlike brazilin, 3-deoxysappanchalcone is antithrombotic: it inhibits platelet aggregation and inhibits the activity of thrombin (FIIa) and activated factor X (FXa) in vitro and in mouse models. The heartwood therefore contains constituents that push platelet function in opposite directions, and the net effect of a whole-drug decoction on haemostasis has not been measured.
Sappanone A
HomoisoflavanoneA homoisoflavanone of the heartwood with reported anti-inflammatory and antioxidant activity in cell models. Over 100 compounds have now been characterised from the drug, of which the brazilins, protosappanins and chalcones are the classes that carry the pharmacology.
⚠ Drug Interactions
Antiplatelet drugs (e.g. aspirin, clopidogrel)
Brazilin, the drug's main marker compound, acts as a novel collagen receptor agonist in human platelets: at low micromolar concentrations it potentiates collagen-induced aggregation and at higher concentrations it triggers aggregation on its own (Chang 2013). This runs against the direction expected from a blood-invigorating herb. Meanwhile 3-deoxysappanchalcone from the same heartwood inhibits platelet aggregation and thrombin and factor Xa activity (Han 2025). No study has measured what the whole decoction does to platelet function in a human on antiplatelet therapy.
Clinical note: Do not assume Su Mu simply adds to antiplatelet therapy. In a patient on aspirin or clopidogrel for a stent or recent event, treat this as an unquantified variable, avoid it around procedures, and do not use it as a substitute for antiplatelet cover.
Warfarin and other anticoagulants
3-Deoxysappanchalcone inhibited thrombin (FIIa) and activated factor X (FXa) activity and showed antithrombotic effects in vitro and in vivo (Han 2025). Those are the same targets as direct oral anticoagulants. This is isolated-compound, non-human evidence, and there is no reported case of altered INR or bleeding attributable to Sappan Lignum.
Clinical note: Monitor for bruising or bleeding if the herb is combined with an anticoagulant, and stop it well before surgery.
Pregnancy: contraindicated
Su Mu is a strongly blood-invigorating, stasis-breaking drug and is classed in Chinese practice as contraindicated in pregnancy. The 2026 Journal of Ethnopharmacology review of Sappan Lignum states that toxicological data corroborate that contraindication, and that safety profiles are dose- and extract-dependent rather than uniformly benign.
Clinical note: Do not prescribe at any dose in pregnancy. Also avoid in patients with active heavy menstrual bleeding, in whom a stasis-breaking drug is inappropriate.
Doxorubicin and other cytotoxic chemotherapy
Isolated compounds from C. sappan have shown synergy with doxorubicin, cisplatin and aminoglycosides in cell models, and a brazilin-enriched heartwood extract has been studied against doxorubicin-induced cardiotoxicity. This is preclinical work with isolated fractions; no human pharmacokinetic or outcome data exist, and brazilin also showed higher cytotoxicity in fibroblasts than in some target cells, which the authors flagged as a dosing concern.
Clinical note: Do not add Su Mu to an active chemotherapy regimen on the strength of synergy in cell culture. Refer the decision to the treating oncology team.
Dosage
| Form | Amount | Frequency | Duration | Population | Notes |
|---|---|---|---|---|---|
| decoction | 3–9 g | Daily | — | — | 中国药典 2020 【用法与用量】3～9g。 【注意】孕妇慎用。 【性味与归经】甘、咸，平。归心、肝、脾经。 — Chinese Pharmacopoeia 2020, quoted verbatim; route and cautions preserved. Replaces a cleared category-filler value. |
Evidence Tier
Moderate evidence · 3 studiesRecorded studies by study design, strongest design at the top. This is a study-design tier only, not a GRADE rating: it does not weigh risk of bias, consistency or precision.
Systematic review / meta-analysis
0
Randomized controlled trial
0
Other clinical trial
0
Observational / case report
0
In vitro / animal
3
1 verified · 2 unverified
Show 3 studies
- Brazilin isolated from Caesalpinia sappan L. acts as a novel collagen receptor agonist in human platelets
- Anti-Thrombotic Activity of 3-Deoxysappanchalcone via Inhibiting Platelet Aggregation and Thrombin (FIIa)/Activated Factor X (FXa) Activity
- Brazilin isolated from the heartwood of Caesalpinia sappan L induces endothelium-dependent and -independent relaxation of rat aortic rings
Other / unclassified
0
Verified: design read from PubMed for a DOI that resolves to the cited paper Unverified: taken from the study's recorded description
Clinical Studies
Brazilin isolated from Caesalpinia sappan L. acts as a novel collagen receptor agonist in human platelets
In washed human platelets, brazilin at 1-10 micromolar potentiated collagen-induced aggregation and at 20-50 micromolar directly triggered aggregation, acting through the collagen receptor pathway. This is a clinically important reversal of the effect a practitioner would expect from a blood-invigorating herb, and it is the single strongest reason to be cautious about combining the drug with antiplatelet therapy in either direction.
Anti-Thrombotic Activity of 3-Deoxysappanchalcone via Inhibiting Platelet Aggregation and Thrombin (FIIa)/Activated Factor X (FXa) Activity
3-Deoxysappanchalcone, a chalcone of C. sappan heartwood, inhibited platelet aggregation and the enzymatic activity of thrombin and activated factor X, with antithrombotic effects confirmed in animal models. Read together with the brazilin platelet work, this shows the heartwood contains constituents acting in opposite directions on haemostasis.
Brazilin isolated from the heartwood of Caesalpinia sappan L induces endothelium-dependent and -independent relaxation of rat aortic rings
Brazilin relaxed isolated rat aortic rings through both endothelium-dependent and endothelium-independent mechanisms. This is ex vivo vascular pharmacology in rat tissue and provides a plausible mechanism for the drug's traditional use in blood stasis, but it says nothing about blood pressure in patients.
⚠ Safety & Contraindications
- Pregnancy
- Bleeding disorders
Contraindications
Its use is prohibited in pregnant women or female with profuse menstruation or patients with blood deficiency and no blood stasis.
Source: Xi S, Gong Y. Essentials of Chinese Materia Medica and Medical Formulas. Academic Press/Elsevier, 2017, pp. 247–250.
Historical Texts
Xin Xiu Ben Cao (Tang Ben Cao)
Tang dynastyHai Yao Ben Cao
Tang to Five DynastiesBen Cao Gang Mu
Ming dynastyReferences
- Chen W, Li X, Hu B, Huang Y, Zhong J, Wu Y, Xu F, Du H, Liu B, Liu Z. Progresses in ethnopharmacological use, phytochemistry, pharmacology, clinical application, pharmacokinetics, quality control and safety of Sappan Lignum (Sumu): A review . Journal of Ethnopharmacology (2026) [DOI]
- Rajput MS, Nirmal NP, Nirmal SJ, Santivarangkna C. Bio-actives from Caesalpinia sappan L.: Recent advancements in phytochemistry and pharmacology . South African Journal of Botany (2022) [DOI]
- Nirmal NP, Rajput MS, Prasad RGSV, Ahmad M. Brazilin from Caesalpinia sappan heartwood and its pharmacological activities: A review . Asian Pacific Journal of Tropical Medicine (2015) [DOI]
- Asevedo EA, Ramos Santiago BM, Kim B, Syahputra RA, Park MN, Ribeiro PPC, Kim B. Unlocking the therapeutic mechanism of Caesalpinia sappan: a comprehensive review of its antioxidant and anti-cancer properties, ethnopharmacology, and phytochemistry . Frontiers in Pharmacology (2025) [DOI]
This information is for educational purposes only and is not intended to replace professional medical advice. Always consult a qualified healthcare provider before using any herbal remedy, especially if you are pregnant, nursing, or taking medications.
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