Eucommia Bark (Du Zhong)

Eucommia ulmoides
Evidence Level
Moderate
3 Clinical Trials
5 Documented Benefits
3/5 Evidence Score

Bark of Eucommia ulmoides — endemic to China, used in TCM for 2,000+ years for kidney/liver tonic, joint support, hypertension, and bone health. Greenway 2011 RCT showed standardized extract (500 mg 3x/day) reduced BP by 7.5/3.9 mmHg. The only temperate tree producing gutta-percha latex — distinctive among medicinal plants.

Studied Dose BLOOD PRESSURE (Greenway 2011 RCT protocol): 500 mg standardized extract 3x daily (1.5 g/day total), standardized to 8% pinoresinol diglucoside. AYURVEDIC/TCM TRADITIONAL: 6-15 g raw bark in decoction OR 300-1,000 mg/day standardized extract. Take with food. NOTE: This tree is the only known temperate tree producing gutta-percha — a natural latex polymer that gives bark fibers a distinctive elastic quality (visible 'rubber threads' when fresh bark is broken). Quality bark from authenticated Qinling Mountains source (Shaanxi Province, China — the 'dao di' geo-authenticated origin) considered superior. Choose products specifying iridoid/lignan content; widely available. Well-tolerated long-term.
Active Compound Iridoids (geniposidic acid, aucubin), lignans (pinoresinol diglucoside, syringaresinol diglucoside, liriodendrin), phenolic acids (chlorogenic acid, caffeic acid), flavonoids, gutta-percha (natural latex polymer)

Benefits

Modest blood pressure reduction (Greenway 2011 RCT)

Greenway 2011 (PMID 22214253, J Med Food) — randomized controlled trial. Study 3: 30 healthy adults with BP 120-160/80-100 mmHg given 1 g eucommia extract 3x daily for 2 weeks vs placebo with 24-hour ambulatory BP monitoring. RESULT: BP reduced by AVERAGE 7.5/3.9 mmHg (p<0.008). Mechanism: nitric oxide enhancement + beta-adrenergic blocking activity (Study 2 in same paper). Reasonable adjunct for prehypertension/early hypertension.

Bone health and osteoporosis prevention (preclinical evidence)

TCM traditional indication for 'strengthening bones and muscles.' Modern preclinical evidence supports osteoporosis benefit: aucubin and geniposidic acid modulate BMP2/Smads and Wnt/β-catenin pathways; pinoresinol diglucoside affects OPG/RANKL signaling in osteoblast/osteoclast balance. 2025 review (PMID 40630123) confirms bone-protective mechanisms. Limited large rigorous human osteoporosis RCTs but consistent mechanistic + traditional use evidence.

Anti-inflammatory and joint support

TCM uses for low back pain, knee pain, joint stiffness aligns with anti-inflammatory mechanisms. Eucommia extract inhibits TNF-α and NO production in rheumatoid synoviocytes (in vitro and animal models). Yan 2022 (PMID 36060766) showed gut microbiota modulation enriching Parabacteroides — independent anti-hypertensive mechanism but also relevant to inflammation. Modest evidence for joint support claims.

Hepatoprotective and renal support (preclinical)

Animal models show eucommia extracts reduce hepatic injury in CCl4 and other toxin models, and provide renal protection. TCM traditional 'tonifying liver and kidney' classification supported mechanistically by antioxidant + anti-inflammatory + adaptogenic activities. Human clinical translation limited.

Anti-fatigue / adaptogenic effects

Animal studies show eucommia extract increases swimming endurance times, reduces lactate accumulation, and modulates HPA axis stress response. TCM 'tonic' classification (bu yao) consistent with adaptogenic activity — comparable to ginseng but with distinct chemistry. Limited human studies.

Mechanism of action

1

Beta-adrenergic blocking activity (BP mechanism)

Greenway 2011 Study 2 demonstrated eucommia extract (0.5% w/v) reduced isoproterenol-stimulated lipolysis from 2.67 to 1.4 times buffer control (p<0.001) in human fat cell assay — indicating beta-adrenergic blocking activity. This is a NOVEL plant-based beta-blocker mechanism. Combined with NO enhancement, explains BP reduction observed in clinical trial.

2

Nitric oxide synthesis enhancement

Eucommia extract increases endothelial NO production, contributing to vasodilation and BP reduction. Mechanism involves multiple pathways including NOS upregulation and oxidative stress reduction. Cumulative effect with beta-blocking activity creates dual cardiovascular benefit.

3

Bone modulation: BMP2/Smads, Wnt/β-catenin pathways

Aucubin and geniposidic acid (iridoids) modulate bone morphogenetic protein-2 (BMP2)/Smads signaling and Wnt/β-catenin pathway — both critical for osteoblast differentiation and bone mineralization. Pinoresinol diglucoside affects OPG/RANKL ratio, the master switch for osteoclast bone resorption. Combined effects support bone formation > resorption — relevant to age-related osteoporosis.

4

Gut microbiota modulation (Parabacteroides enrichment)

Yan 2022 PMID 36060766 demonstrated eucommia bark extract enriches Parabacteroides in gut microbiota — and that this strain itself produces anti-hypertensive effects via reducing renal IL-17A and serum IL-6. Demonstrates gut-mediated mechanism beyond direct pharmacological effects. Important for understanding 'whole-extract' TCM herbs that exceed expected molecular pharmacology.

Clinical trials

1
Greenway 2011 — Eucommia for Hypertension (Pivotal RCT)
PubMed

Three-study clinical trial (Greenway F, Liu Z, Yu Y, Gupta A 2011, J Med Food 14(7-8):745-749, doi:10.1089/jmf.2010.0255, PMID 22214253). NCT00626132.

Study 1: 24 healthy adults (BP 120-160/80-100) randomized to eucommia 500 mg 3x daily for 8 weeks. Study 3: 30 healthy adults (BP 120-160/80-100) randomized to 1 g eucommia 3x daily for 2 weeks with 24-hour ambulatory BP monitoring. Standardized extract: 8% pinoresinol di-β-D-glucoside.

Study 1: NO BP difference (likely under-dosed at 500 mg). Study 2 (in vitro): Eucommia at 0.5% w/v reduced isoproterenol-stimulated lipolysis by ~50% (p<0.001) — beta-blocker activity. Study 3: BP reduced by AVERAGE 7.5/3.9 mmHg (p<0.008) at higher dose. Conclusion: 'Standardized Eucommia extract reduced BP and has beta-adrenergic blocking activity. Eucommia may be appropriate nutraceutical intervention for prehypertension.' Foundational Western RCT for the cardiovascular indication.

2
Yan 2022 — Eucommia and Gut Microbiota / BP
PubMed

Animal mechanism study (Yan W et al. 2022, PMID 36060766).

Animal model study examining how eucommia bark extract modulates gut microbiota and the resulting cardiovascular effects.

Eucommia extract specifically enriched Parabacteroides bacteria in gut microbiota. The Parabacteroides strain demonstrated INDEPENDENT anti-hypertensive effects by reducing renal IL-17A and serum IL-6 — establishing a gut-mediated mechanism for cardiovascular benefit beyond direct pharmacology. Modern explanation for traditional 'tonifying' herb effects.

3
Wang 2019 — Eucommia Bone Disease Review
PubMed

Comprehensive review (Wang CY, Tang L, He JW, Li J, Wang YZ 2019, J Pharm Pharmacol 71(8):1149-1160).

Review of Eucommia ulmoides and bioactive compounds for bone diseases — over 119 publications screened down to relevant aging-related bone disease studies.

Documented EU formulas, extracts, and bioactive components promote osteogenesis, suppress bone resorption, and exert anti-inflammatory and antioxidant properties. Supports TCM traditional 'strengthening bones and muscles' indication with modern mechanistic evidence. Concluded therapeutic benefits support development for preventing and treating aging-related bone diseases.

About this ingredient

About the active ingredient

Eucommia ulmoides Oliver (Du Zhong, 杜仲) is a deciduous tree of the Eucommiaceae family — the SOLE remaining member of its genus and family (a 'living fossil'), endemic to central China. The bark has been used in TCM for over 2,000 years (catalogued in Shennong Bencaojing as an 'upper herb') for: kidney/liver tonification, strengthening bones/muscles, knee/back pain, hypertension, miscarriage prevention. Sometimes called 'hardy rubber tree' because it's the only known temperate tree producing gutta-percha — a natural rubber-like latex polymer (chemically isomer of natural rubber).

Visible white fibers between fresh bark layers — distinctive identification feature. PHYTOCHEMISTRY: IRIDOIDS — geniposidic acid, aucubin, ulmoside (characteristic for Eucommia); LIGNANS — pinoresinol diglucoside (PDG, marker compound, often the standardization target), syringaresinol diglucoside, liriodendrin; PHENOLIC ACIDS — chlorogenic acid (substantial amount), caffeic acid, ferulic acid; FLAVONOIDS — quercetin, kaempferol; OTHER — gutta-percha polymer (~5-10% of bark dry weight, source of the latex threads), polysaccharides, amino acids. The Qinling Mountains region (Shaanxi Province, ~33-34° N) is the geo-authenticated 'dao di' source for premium quality bark.

Standardized extracts typically 8% pinoresinol diglucoside (Greenway protocol). MARKET FORMS: dried bark, powdered bark, hot-water extract, ethanol extract, capsules, tea bags. Used both individually and in TCM combinations (multiple classical formulas including Du Huo Ji Sheng Tang for arthritic conditions).

EVIDENCE: 3/5 reflects: (1) Greenway 2011 PMID 22214253 RANDOMIZED CONTROLLED TRIAL n=30 demonstrating significant 7.5/3.9 mmHg BP reduction with mechanistic basis (beta-blocking + NO enhancement), (2) Yan 2022 PMID 36060766 modern gut microbiota mechanism study, (3) Wang 2019 + 2025 reviews supporting bone health applications, (4) extensive preclinical literature for cardiovascular, bone, anti-inflammatory effects, (5) 2,000+ years of TCM clinical use. Limited by relatively few large rigorous Western RCTs and primarily Asian-based research base. SAFETY: Excellent — long history as tea consumption in Japan/China.

Best positioned as: (a) reasonable adjunct for prehypertension or early hypertension (1.5-3 g/day standardized extract), (b) bone health support in osteoporosis prevention contexts (mechanistically supported, traditional use), (c) joint support for low back/knee pain (TCM traditional, limited modern RCT), (d) component of TCM combinations under practitioner guidance, (e) generally tolerable long-term as Asian-style tea consumption. Honest framing: one of the better-evidenced TCM cardiovascular herbs with a meaningful Western RCT, modest effect size but consistent with mild antihypertensive class.

Side effects and drug interactions

Common Potential side effects

Generally extremely well-tolerated; long history of safe use as tea in Japan/China.
Mild GI upset at high doses.
Theoretical hypotension at high doses or combined with antihypertensives.
Pregnancy: actually traditionally USED in TCM for 'preventing miscarriage' — but modern safety data limited.
Allergic reactions: rare.
Quality variability between products and bark sources.

Important Drug interactions

Antihypertensives: theoretical additive BP-lowering; monitor.
Beta-blockers (atenolol, metoprolol, propranolol): theoretical additive effects given beta-blocking activity.
Diabetes medications: animal evidence for modest glucose effects; minor consideration.
Anticoagulants: minimal documented interactions.
Most medications: no clinically significant documented interactions at typical doses.

Frequently asked questions about Eucommia Bark (Du Zhong)

What is the recommended dosage of Eucommia Bark (Du Zhong)?

The clinically studied dose for Eucommia Bark (Du Zhong) is BLOOD PRESSURE (Greenway 2011 RCT protocol): 500 mg standardized extract 3x daily (1.5 g/day total), standardized to 8% pinoresinol diglucoside. AYURVEDIC/TCM TRADITIONAL: 6-15 g raw bark in decoction OR 300-1,000 mg/day standardized extract. Take with food. NOTE: This tree is the only known temperate tree producing gutta-percha — a natural latex polymer that gives bark fibers a distinctive elastic quality (visible 'rubber threads' when fresh bark is broken). Quality bark from authenticated Qinling Mountains source (Shaanxi Province, China — the 'dao di' geo-authenticated origin) considered superior. Choose products specifying iridoid/lignan content; widely available. Well-tolerated long-term.. Always follow product labeling and consult a healthcare provider for personalized dosing recommendations.

What is Eucommia Bark (Du Zhong) used for?

Eucommia Bark (Du Zhong) is studied for modest blood pressure reduction (greenway 2011 rct), bone health and osteoporosis prevention (preclinical evidence), anti-inflammatory and joint support. Greenway 2011 (PMID 22214253, J Med Food) — randomized controlled trial. Study 3: 30 healthy adults with BP 120-160/80-100 mmHg given 1 g eucommia extract 3x daily for 2 weeks vs placebo with 24-hour ambulatory BP monitoring.

Are there side effects from taking Eucommia Bark (Du Zhong)?

Reported potential side effects may include: Generally extremely well-tolerated; long history of safe use as tea in Japan/China. Mild GI upset at high doses. Always consult a healthcare provider before starting any new supplement, especially if you have underlying conditions or take medications.

Does Eucommia Bark (Du Zhong) interact with medications?

Known drug interactions may include: Antihypertensives: theoretical additive BP-lowering; monitor. Beta-blockers (atenolol, metoprolol, propranolol): theoretical additive effects given beta-blocking activity. Consult a pharmacist or healthcare provider if you take prescription medications.

Is Eucommia Bark (Du Zhong) good for cardiovascular?

Yes, Eucommia Bark (Du Zhong) is researched for Cardiovascular support. Greenway 2011 (PMID 22214253, J Med Food) — randomized controlled trial. Study 3: 30 healthy adults with BP 120-160/80-100 mmHg given 1 g eucommia extract 3x daily for 2 weeks vs placebo with 24-hour ambulatory BP monitoring. RESULT: BP reduced by AVERAGE 7.5/3.9 mmHg (p<0.008).