Xu Duan (续断) — Teasel Root TCM Herb | Fractures, Kidney Deficiency & Miscarriage

At a Glance

• Herb: Xu Duan
• Chinese name: 续断 (Xù Duàn)
• Latin name: Radix Dipsaci
• Nature: Slightly Warm
• Taste: Bitter / Sweet / Acrid
• Meridian: Liver / Kidney
• Category: Herbs that Tonify Yang
• Introduction: Xu Duan (续断, Radix Dipsaci) is the dried root of Dipsacus japonicus Miq. or D. asper Wall. ex C.B.Clarke, tall biennials or perennials native to mountainous regions of central and southwest China. The name 续断 — ‘continue the broken’ — eloquently describes its foremost action: mending fractured bones, torn sinews, and disrupted tissue continuity. First recorded in the Shennong Bencao Jing, Xu Duan is both a Kidney-Liver tonic and a trauma herb, bridging two clinical categories that rarely overlap. Its unique triple action — tonifying Liver-Kidney, invigorating blood and alleviating pain, and stabilising the foetus — makes it especially valuable in orthopaedics, gynaecology, and geriatric medicine.

Action

• Tonifies the Liver and Kidney: Supplements Liver-Kidney deficiency presenting as lumbar pain, knee soreness, and weakness — particularly when deficiency underlies traumatic or chronic musculoskeletal injury. 2. Strengthens sinews and bones: Promotes healing of fractures and torn ligaments; the primary herb for bone fracture recovery in TCM orthopaedics. 3. Stabilises the foetus and stops uterine bleeding: Warms the Chong and Ren vessels to prevent threatened miscarriage with uterine bleeding. 4. Invigorates blood and alleviates pain: Moves blood to reduce traumatic injury pain and chronic Bi pain.

Clinical Application

• Xu Duan is the foremost herb in TCM orthopaedics — it appears in virtually every formula for fracture healing, sprain, and chronic joint degeneration from Liver-Kidney deficiency. Combined with Du Zhong and Sang Ji Sheng in Du Huo Ji Sheng Wan for Bi syndrome with deficiency. In Shou Tai Wan (寿胎丸) with Tu Si Zi, Sang Ji Sheng, and E Jiao, it is the classical prescription for habitual and threatened miscarriage — its ability to both warm the Chong vessel and move blood simultaneously prevents stasis while supporting the foetus. Salt-processed Xu Duan (Yan Xu Duan) is preferred for tonic applications; wine-processed (Jiu Xu Duan) for blood-moving and fracture healing.

Precautions

• Use with caution in cases of excess heat without Liver-Kidney deficiency. Avoid raw herb in threatened miscarriage — wine-processing is preferred for trauma; salt-processing for tonic applications. Generally considered safe with few adverse effects at standard doses (9–15 g).

Formula

• Du Huo Ji Sheng Wan (独活寄生丸): Du Huo, Sang Ji Sheng, Du Zhong, Xu Duan, Niu Xi, Fang Feng, Xi Xin, Dang Gui, Chuan Xiong, Sheng Di Huang, Rou Gui, Fu Ling, Ren Shen, Bai Shao, Gan Cao.
• Shou Tai Wan (寿胎丸): Tu Si Zi, Sang Ji Sheng, Xu Duan, E Jiao.
• Xu Duan Wan (续断丸): Xu Duan, Du Zhong, Fang Feng, Chuan Xiong — for chronic Bi syndrome.

Combinations

• Xu Duan + Du Zhong + Sang Ji Sheng + Niu Xi (Du Huo Ji Sheng Wan): Bi syndrome with Liver-Kidney deficiency. Source: Prescriptions Worth a Thousand Gold (备急千金要方).
• Xu Duan + Tu Si Zi + Sang Ji Sheng + E Jiao (Shou Tai Wan): Threatened and habitual miscarriage from Kidney deficiency. Source: Medical Formulas Collected and Analyzed (医方集解).
• Xu Duan + Gu Sui Bu + Zi Ran Tong: Fracture healing — promotes callus formation and bone union. Source: Orthopaedic formula tradition.
• Xu Duan + Dang Gui + Chuan Xiong: Traumatic injury with blood stasis and pain. Source: Formulas to Aid the Living (济生方).
• Xu Duan + Sang Ji Sheng + Du Zhong + E Jiao: Uterine bleeding in pregnancy from Kidney deficiency and blood deficiency. Source: Obstetric formula tradition.

Pharmacological Effects

• Asperosaponin VI significantly
  • Bone-healing: promotes osteoblast proliferation and differentiation, accelerates fracture callus formation, and increases bone mineral density in animal models
• Multiple in vivo studies confirm prevention of ovariectomy-
  • Anti-osteoporosis: induced bone loss
• Loganin and saponins
  • Uterine protection: inhibit uterine smooth muscle contractions — consistent with anti-miscarriage action
• Chlorogenic acid and iridoids
  • Anti-inflammatory: inhibit COX-2, NF-κB, and reduce joint inflammation
• Asperosaponin VI
  • Neuroprotective: protects neurons from amyloid-beta toxicity in Alzheimer’s models

Classic Description

• 《神农本草经》(Shennong Bencao Jing, circa 200 CE): ‘续断，味苦，微温。主伤寒，补不足，金创痈伤，折跌，续筋骨，妇人乳难，崩中漏下，益气力。’ (Xu Duan: bitter flavour, slightly warm. Governs cold damage, supplements insufficiency, metal wound abscesses, fractures, continues sinews and bones, difficult lactation in women, flooding and spotting; benefits qi and strength.)
• 《本草纲目》(Bencao Gangmu, 1596): ‘续断，补肝肾，通血脉，理筋骨，治妇人崩中、胎漏，为伤科要药。’ (Xu Duan supplements Liver and Kidney, unblocks blood vessels, regulates sinews and bones, treats flooding and spotting and foetal leakage in women — it is the essential herb in trauma medicine.)
• 《本草求真》(Bencao Qiuzhen, 1773): ‘续断，同补骨脂、杜仲，则固精壮骨；同当归、艾叶，则和血暖宫；同地黄、人参，则滋补气血。’ (Xu Duan: combined with Bu Gu Zhi and Du Zhong it consolidates essence and strengthens bones; with Dang Gui and Ai Ye it harmonises blood and warms the uterus; with Di Huang and Ren Shen it nourishes qi and blood.)