Du Zhong (Eucommia Bark)

Chinese Herb Actions

Chinese Herb Dosage

• What is the typical dosage of Du Zhong?

  Roughly 6–15 g in decoction — the owner’s notes give 3–5 qián, which at the common modern conversion (~3 g per qián) is about 6–15 g, consistent with standard materia medica ranges. Du Zhong is used either raw (Du Zhong) or dry-fried / salt-fried (Chǎo Du Zhong), the fried form being the usual choice to strengthen the Kidney-tonifying, back-strengthening action.

  Source: owner’s Five Branches notes; standard materia medica ranges. Reference only — not a prescription.

Chinese Herb Contraindications & Cautions

• Are there cautions for Du Zhong?

  Du Zhong is warm and, like the Tonify-Yang herbs as a class, can injure yin — the chapter caution is to avoid these herbs in fire from yin deficiency (yin-xu heat). The notes flag Du Zhong specifically: use it carefully in yin-deficiency / ascendant-yang pictures, and combine it with other herbs rather than using it alone in those cases. It is traditionally regarded as gentle and well tolerated within its indicated deficiency patterns, and is best used under a qualified practitioner, particularly in pregnancy.

  Note: The classical “calm the fetus” use in pregnancy is a traditional indication but a clinical context — flagged for practitioner oversight rather than self-use.

  Source: owner’s Five Branches notes; blood/yang-tonic chapter cautions.

Chinese Herb Toxicity & Overdose

• Low. Eucommia bark is regarded as a safe, well-tolerated tonic; the reviewed literature reports no major adverse effects at studied doses and provides no formal human toxicity threshold.

  Note: Absence of reported toxicity is not the same as an established safety ceiling — no formal human toxicity threshold has been set in the reviewed research.

  Source: materia medica consensus; reviewed research (below) reports no toxicity signal but sets no human threshold.

Herb-Drug Interactions

• No well-established clinical herb–drug interactions are documented. Because preclinical research reports blood-pressure-lowering activity (below), a theoretical caution is reasonable alongside antihypertensive medication — this is precautionary, not a demonstrated clinical interaction. (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 there modern research on Eucommia (Du Zhong)?

  Yes, but it is largely preclinical. Characterized constituents of Eucommia ulmoides include lignans (notably pinoresinol diglucoside), iridoids (aucubin, geniposidic acid, asperuloside), phenolics (chlorogenic acid, caffeic acid, rutin, quercetin), flavonoids, and polysaccharides. A comprehensive review catalogues antihypertensive, antioxidant, anti-inflammatory, and bone-protective activities but notes the evidence is largely from cell and animal models, with human clinical data limited.

  • Pinoresinol diglucoside is the marker compound specified for Eucommia bark in the Chinese Pharmacopoeia (2020 ed., minimum content 0.10%), and reviews associate it with the antihypertensive activity seen in animal studies.
  • Blood pressure (animal) — in spontaneously hypertensive rats, a Eucommia (male-flower) aqueous extract lowered blood pressure and modulated the renal ACE2 / angiotensin-(1–7) axis; an animal mechanistic study, not evidence of a clinical antihypertensive effect.
  • Bone-protective (animal) — improved bone mineral density and trabecular microarchitecture via BMP/SMAD, Wnt/β-catenin, and OPG/RANKL signalling in animal models of osteoporosis.

  Human clinical evidence remains limited; most support is laboratory and animal research.

  Sources: PMID 27042191, PMC 4793136 (health-promoting properties review); PMC 12845223 (bioactive compounds review, Chinese Pharmacopoeia marker detail); PMC 7210558 (male-flower extract in spontaneously hypertensive rats, animal study); PMC 12868233 (osteoprotective scoping review, preclinical). Research context, not a therapeutic claim.

Chinese Herb Notes

• How is Du Zhong different from Xu Duan?

  Both tonify the Liver and Kidney, ease lower-back pain, and calm a restless fetus, but Du Zhong is favored for primarily deficiency (xu) pictures. Xu Duan is used more when low-back pain combines wind-damp with Kidney deficiency, and Xu Duan additionally invigorates blood and helps heal injuries “without causing stagnation.”

  • vs Xu Duan — Du Zhong for deficiency-dominant back/knee weakness; Xu Duan for wind-damp with Kidney deficiency, plus blood-invigorating and injury-healing action.
  • Within the Tonify-Yang group — Bensky’s summary places Du Zhong among the yang tonics said to also nourish yin (alongside Dong Chong Xia Cao), i.e. less drying than harsher yang tonics such as Xian Mao or Yin Yang Huo.

  Common combinations: with Xu Duan for a weak, painful lower back and to steady an unsettled pregnancy; with Hu Tao Ren, Bu Gu Zhi, and Gou Ji for Kidney-deficiency weakness of the lower back and knees. It also features in well-known classical formulas including Du Huo Ji Sheng Tang (wind-damp with Liver/Kidney deficiency, low-back pain), You Gui Wan (Kidney yang), Zan Yu Dan (fertility), and Tian Ma Gou Teng Yin (rising Liver yang). (Traditional formula context, not treatment advice.)

  Source: owner’s Five Branches notes (differentiation & combinations); Sacred Lotus formula links.