Eucommia Bark (Du Zhong)

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

Eucommia bark (du zhong) is a classic Chinese tonic herb traditionally used to strengthen the bones, tendons, lower back, and knees and to support healthy blood pressure. In Traditional Chinese Medicine terms it is a kidney tonic for structural and skeletal support, and it is also studied for bone and cardiovascular health. It is typically used within traditional formulas or as a decoction or extract, under product or practitioner guidance. Eucommia is generally considered safe within traditional practice; because it may lower blood pressure, those on blood-pressure medication should monitor and check with a knowledgeable practitioner or doctor.

Studied Dose 500 mg standardized extract (8% pinoresinol diglucoside) 3x/day (1.5 g/day). Traditional: 6-15 g raw bark decoction, or 300-1,000 mg/day standardized extract.
Active Compound Iridoids (geniposidic acid, aucubin), lignans (pinoresinol diglucoside, syringaresinol diglucoside, liriodendrin), phenolic acids (chlorogenic acid, caffeic acid), flavonoids, gutta-percha.

Benefits

Supports healthy blood pressure (single patent-formula trial in patients)

In a multicenter, randomized, double-blind, placebo-controlled trial (Xu 2022), Quanduzhong capsules — a standardized Eucommia ulmoides patent formula — were given to patients with grade-1 hypertension at low-to-moderate risk. Office blood pressure fell by roughly 7.62/4.66 mmHg versus placebo (p<0.05). This is disease-population data on one specific patent capsule, not a general 'eucommia extract'; an earlier small Western trial (Greenway 2011) found no effect at 500 mg and only a modest change at a higher dose. For people with normal blood pressure the herb's blood-pressure use is traditional, and controlled evidence in healthy adults is limited. Anyone with high blood pressure or taking blood-pressure medication should work with a clinician rather than self-treat.

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. Limited large rigorous human osteoporosis RCTs but consistent mechanistic and traditional-use evidence.

Anti-inflammatory and joint support

TCM uses for low back pain, knee pain, and joint stiffness align with anti-inflammatory mechanisms. Eucommia extract inhibits TNF-α and NO production in rheumatoid synoviocytes (in vitro and animal models), and modulates gut microbiota in ways 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)

Eucommia extract (0.5% w/v) reduced isoproterenol-stimulated lipolysis from 2.67 to 1.4 times buffer control in a human fat cell assay — indicating beta-adrenergic blocking activity. This is a novel plant-based beta-blocker mechanism. Combined with NO enhancement, it explains the BP reduction observed in clinical trials.

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)

Eucommia bark extract enriches Parabacteroides in gut microbiota — and that strain itself produces anti-hypertensive effects via reducing renal IL-17A and serum IL-6. This demonstrates a gut-mediated mechanism beyond direct pharmacological effects, important for understanding 'whole-extract' TCM herbs that exceed expected molecular pharmacology.

Clinical trials

1
Eucommia for Blood Pressure (small early Western trial, mixed results)

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

Study 1: 24 adults with elevated-to-stage-1 blood pressure (BP 120-160/80-100) randomized to eucommia 500 mg 3x daily for 8 weeks. Study 3: 30 adults with elevated-to-stage-1 blood pressure (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. the standardized extract lowered blood pressure in this study population.' Interpretation: this is a small, early Western trial with a null low-dose (500 mg) arm and an in-vitro arm; it does not establish generic eucommia extract as a blood-pressure treatment. A separate, more recent RCT of the Quanduzhong patent capsule (Xu 2022) in grade-1 hypertension patients found modest reductions. Diagnosed high blood pressure should be managed with a clinician, not self-treated with a supplement.

2
Eucommia and Gut Microbiota / BP

Animal mechanism study (Yan W et al. 2022).

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 — suggesting a possible gut-mediated mechanism in an animal model, beyond direct pharmacology. Modern explanation for traditional 'tonifying' herb effects.

3
Eucommia Bone Disease Review

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.

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 eucommia bark used for?

Eucommia bark (du zhong) is a Chinese herb used as a kidney tonic in TCM terms, supporting bones, joints, lower-back strength, and healthy blood pressure. It is a classic herb for skeletal and structural support.

What is eucommia good for?

It is traditionally used to strengthen bones, tendons, and the lower back and knees, support healthy blood pressure, and as a tonic in pregnancy (in TCM). It is studied for bone and cardiovascular support.

How much eucommia bark should I take?

It is used within traditional formulas or as a decoction or extract; follow product or practitioner guidance.

Is eucommia bark safe?

Within traditional practice it is generally considered safe. Because it may lower blood pressure, those on blood-pressure medication should monitor and check with a practitioner or doctor.

What is Eucommia Bark?

Eucommia bark (du zhong) is a classic Chinese tonic herb traditionally used to strengthen the bones, tendons, lower back, and knees and to support healthy blood pressure.

What is the recommended dosage of Eucommia Bark?

The clinically studied dose is 500 mg standardized extract (8% pinoresinol diglucoside) 3x/day (1.5 g/day). Traditional: 6-15 g raw bark decoction, or 300-1,000 mg/day standardized extract. Always follow the product label and check with a healthcare provider for personal advice.

Is Eucommia Bark safe, and does it have side effects?

For most healthy adults, Eucommia Bark is well tolerated at studied doses. Reported effects can include: Generally extremely well-tolerated; long history of safe use as tea in Japan/China. Mild GI upset at high doses. It may also interact with some medications. Eucommia Bark is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Eucommia Bark interact with any medications?

Possible interactions include: Antihypertensives: theoretical additive BP-lowering; monitor. Beta-blockers (atenolol, metoprolol, propranolol): theoretical additive effects given beta-blocking activity. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Eucommia Bark?

NutraSmarts rates the evidence for Eucommia Bark as Moderate (3 out of 5). It is backed by 3 clinical trials and 1 cited reference summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(1 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Xu X, Tian W, Duan W, et al. Quanduzhong capsules for the treatment of grade 1 hypertension patients with low-to-moderate risk: A multicenter, randomized, double-blind, placebo-controlled clinical trial. Front Pharmacol. 2022;13:1014410..PubMedUsed to support: Randomized trial of Eucommia ulmoides (Quanduzhong) for grade 1 hypertension.