Chái Hú (柴胡) — Bupleurum Root

Chái Hú (Bupleurum chinense) is the principal Liver-Qi-regulating herb in Chinese medicine. If you have ever taken a Chinese herbal formula for stress, PMS, depression, IBS, premenstrual breast tenderness, hot flushes or hormonal imbalance, there is a very high chance Chai Hu was the lead herb. It is the principal ingredient in Xiao Yao San, Jia Wei Xiao Yao San, Chai Hu Shu Gan San, Xiao Chai Hu Tang and many others. Its ability to soothe the Liver, resolve emotional and physical constraint, raise sunken Qi and balance the Liver-Spleen relationship makes it indispensable in modern stressful life.

On this page

1. What is Chai Hu (Bupleurum)?
2. Properties
3. Actions and indications
4. Active compounds
5. Stress, mood and PMS
6. Women’s health applications
7. Liver protection and detoxification
8. Immune-modulating effects
9. Metabolic and cholesterol effects
10. Key Chai Hu formulas
11. Modern research
12. Incompatibilities
13. Cautions and contraindications
14. Treatment at my clinic
15. Frequently asked questions about Chai Hu

1. What is Chai Hu (Bupleurum)?

Chái Hú (柴胡) is the dried root of Bupleurum chinense or Bupleurum scorzonerifolium, native to East Asia. It has been used in Chinese medicine for at least 2,000 years and appears in the Han dynasty Shang Han Lun (c. 220 CE) as the lead herb in numerous classical formulas. Its English names are Bupleurum root or Thorowax root. The root is harvested in spring or autumn, dried and either used raw, vinegar-fried (to enhance Liver-targeted action), or wine-fried (to enhance ascending action).

It belongs to the category of Herbs that release the Exterior in the Chinese Materia Medica and is one of the most important and widely prescribed herbs in traditional Chinese medicine (TCM). I prescribe Chái Hú as part of bespoke herbal formulas from pharmaceutical-grade granules sourced from Sun Ten in Taiwan — independently tested to the highest international quality and safety standards. Online consultations are available for patients who cannot attend my clinic in person.

2. Properties

3. Actions and indications

Principal actions

1. Disperses Liver Qi stagnation and relieves constraint — the most important action; addresses depression, irritability, PMS, breast tenderness, IBS, hypochondrial pain and emotional volatility
2. Releases the Exterior and reduces fever in Shao Yang patterns — alternating fever and chills, bitter taste, ribcage discomfort, nausea
3. Raises sunken Yang Qi — used with Huang Qi in Bu Zhong Yi Qi Tang for prolapse and chronic Spleen Qi sinking
4. Clears Heat and disperses constraint Heat

Indications

1. Liver Qi stagnation with flank pain, irritability, depression and chest tightness
2. Premenstrual syndrome, irregular menstruation and dysmenorrhoea from Liver Qi stagnation
3. Alternating fever and chills, bitter taste and dry throat from Shao Yang disorders
4. Prolapse of organs from middle Qi sinking (combined with Huang Qi)
5. Emotional stress, anxiety and depression
6. Headache, dizziness and blurred vision from Liver Yang rising
7. Chronic liver disease, fatty liver, raised liver enzymes

4. Active compounds

• Saikosaponins (a, c, d, f) — the principal bioactives. Anti-inflammatory, hepatoprotective, immunomodulatory.
• Bupleurumol — antipyretic and analgesic effects.
• Polysaccharides — immune-modulating.
• Flavonoids and lignans — antioxidant.
• Essential oil components — contribute to its surface-releasing action.

Saikosaponin d in particular has the most extensive research literature, with documented effects on liver fibrosis, steroid receptors, oxidative stress and inflammation pathways.

5. Stress, mood and PMS

Chai Hu’s most clinically valuable use today is in the treatment of stress-related disorders. Modern Chinese-language and international research on Xiao Yao San (the most prescribed Chai Hu-based formula) shows:

• Antidepressant effects comparable to fluoxetine in mild-moderate depression in multiple RCTs and meta-analyses.
• Reduction in PMS symptoms — bloating, breast tenderness, irritability, mood swings.
• Reduction in functional dyspepsia and IBS symptoms when stress is the trigger.
• Modulation of the HPA axis — reduces cortisol; increases brain BDNF.
• Effects on serotonin, dopamine and noradrenaline pathways.

For practical purposes, if your symptoms worsen with stress and improve when you relax — irritability, PMS, breast tenderness, headaches at the temples, sighing, IBS, premenstrual flares — Chai Hu (within an appropriate formula) is likely to help.

6. Women’s health applications

Chai Hu is the central herb for almost every women’s health pattern with a Liver Qi stagnation component:

• PMS and PMDD — Xiao Yao San is the workhorse formula.
• Irregular periods — when stress and emotional component are dominant.
• Premenstrual breast tenderness — Chai Hu Shu Gan San.
• Endometriosis-related dysmenorrhoea — combined with blood-moving herbs.
• Fibroids and breast cysts — combined with phlegm-resolving and blood-moving herbs.
• Hyperprolactinaemia — Xiao Yao San reduces prolactin in some trials.
• Hot flushes and perimenopausal mood swings — Jia Wei Xiao Yao San with added heat-clearing herbs.
• Postnatal depression — combined with blood-building herbs in Gui Pi Tang variations.

7. Liver protection and detoxification

Modern research has confirmed substantial hepatoprotective effects:

• Reduces ALT and AST in chemical-induced liver injury models.
• Anti-fibrotic — inhibits hepatic stellate cell activation.
• Anti-inflammatory in liver tissue.
• Supports Phase I and II detoxification of hormones and toxins.
• Used in modern Chinese clinical practice for chronic hepatitis B/C, fatty liver and drug-induced liver injury.

For patients with raised liver enzymes, fatty liver or oestrogen-dominance from sluggish liver clearance, Chai Hu-based formulas are commonly used alongside diet, exercise and weight management.

8. Immune-modulating effects

Saikosaponins modulate immune function — supporting it in deficient states and dampening it in inflammatory states:

• Antipyretic effect documented in Shao Yang fever patterns.
• Anti-inflammatory effects in autoimmune models.
• Used in modern formulas for chronic inflammatory disease, including some autoimmune conditions, under specialist supervision.

9. Metabolic and cholesterol effects

• Modest cholesterol-lowering effect documented in animal studies and some clinical trials.
• Improves insulin sensitivity in metabolic syndrome models.
• May support fatty liver reversal alongside diet and weight loss.

10. Key Chai Hu formulas

• Xiao Yao San — Free and Easy Wanderer; the workhorse Chai Hu formula. Indicated for PMS, mild depression, stress-related IBS, perimenopausal mood swings.
• Jia Wei Xiao Yao San — Xiao Yao San plus Mu Dan Pi and Zhi Zi to clear heat. For Liver Qi stagnation with heat — irritability, premenstrual flushing, hot flushes.
• Chai Hu Shu Gan San — stronger Qi-moving formula for marked premenstrual breast tenderness and emotional constraint.
• Xiao Chai Hu Tang — Minor Bupleurum Decoction; classical Shao Yang formula for alternating fever and chills, bitter taste, nausea, costal discomfort.
• Da Chai Hu Tang — Major Bupleurum Decoction; Shao Yang plus Yang Ming heat with constipation.
• Si Ni San — Frigid Extremities Powder; for cold extremities from Liver Qi constraint trapping Yang in the interior.
• Bu Zhong Yi Qi Tang — Tonify the Middle; uses Chai Hu’s “raising sunken Qi” action for prolapse and chronic fatigue.

See the full Chinese herbal medicine formula directory.

11. Modern research

Bupleurum is one of the most clinically important and thoroughly researched Chinese medicinal herbs. Key bioactive constituents include saikosaponins (a, b, c, d), polysaccharides and flavonoids. Research demonstrates that saikosaponins have anti-inflammatory, immunomodulatory, hepatoprotective, antiviral and anti-cancer properties. Chai Hu has been shown to inhibit inflammatory cytokine production (TNF-alpha, IL-6), protect liver cells from damage and modulate glucocorticoid receptor activity — consistent with its role in regulating stress, cortisol and mood. Clinical research supports use in depression, anxiety, premenstrual syndrome, liver disease and as an adjunct in cancer care. The formula Xiao Chai Hu Tang (Minor Bupleurum Decoction) is one of the most studied herbal formulas in the world.

12. Incompatibilities

Chái Hú (柴胡) Bupleurum Root is not listed in either of the two classical incompatibility texts — Shi Ba Fan (Eighteen Antagonisms) or Shi Jiu Wei (Nineteen Mutual Inhibitions). As with every Chinese herb it should be prescribed only as part of a balanced formula by a registered Chinese herbalist (RCHM).

13. Cautions and contraindications

• Yin deficiency with rising fire — high doses can deplete Yin further and worsen heat signs (night sweats, hot flushes, palpitations, irritability). Always paired with Yin-nourishing herbs in such patterns.
• Long-term high-dose use — should be supervised by a practitioner; saikosaponins at very high or prolonged doses have been associated with raised liver enzymes (a paradox given the herb’s hepatoprotective use). At standard clinical doses this is not a concern.
• Liver Fire and true Yin-deficient headache — the ascending, dispersing action may aggravate these patterns.
• Pregnancy — not first-line in pregnancy; can be used carefully in specialist contexts.
• Drug interactions — may modestly affect cytochrome P450 enzymes; tell your prescriber if on any narrow-therapeutic-index medications.

Pattern contraindications

Differentiate the pattern carefully before prescribing — matching the formula to the underlying pattern is essential. The practitioner will check pulse, tongue and full case history at every consultation.

Modern drug interactions

Tell your GP that you are taking a Chinese herbal prescription so any interaction with conventional medication can be reviewed.

Important: Chinese herbs should always be prescribed by a fully qualified herbalist who is a member of the Register of Chinese Herbal Medicine (RCHM). Dr (TCM) Attilio D’Alberto is a member of the RCHM and the British Acupuncture Council with over 25 years of clinical experience.

14. Treatment at my clinic

I prescribe Chái Hú as part of tailored herbal formulas for conditions including anxiety, depression, stress, irregular menstrual cycle, PMS, burnout and stress-driven IBS. Every prescription is individually formulated following a full TCM assessment.

I see patients in person at my clinic in Wokingham, Berkshire. Online Chinese herbal medicine consultations are available throughout the UK and internationally. Visit the prices page for consultation fees.

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15. Frequently asked questions about Chai Hu

What is Chai Hu used for?

Chai Hu is the principal Liver Qi-regulating herb in Chinese medicine. It is used for stress-related disorders — PMS, mild depression, irritability, premenstrual breast tenderness, IBS, hypochondrial pain — and for liver protection and the classical Shao Yang fever pattern.

Can I take Chai Hu for PMS?

Yes — Chai Hu within Xiao Yao San or Jia Wei Xiao Yao San is one of the most effective TCM treatments for PMS, with multiple RCTs supporting it. Best taken within a tailored formula prescribed by a practitioner.

Does Chai Hu help depression?

Yes, particularly mild-moderate stress-driven depression. Xiao Yao San (Chai Hu’s principal formula) shows effect sizes comparable to fluoxetine in multiple meta-analyses.

Is Chai Hu safe for the liver?

Yes at standard clinical doses, where it is actively hepatoprotective. Very high doses or prolonged unsupervised use can paradoxically raise liver enzymes; this is why it should be prescribed within a balanced formula by a practitioner.

Can I take Chai Hu with antidepressants?

Generally yes. The combinations prescribed within Xiao Yao San are safe alongside SSRIs and have additive benefit. Always tell your prescriber.

Should I take Chai Hu as a single herb supplement?

Rarely. Single-herb use loses the clinical effect of a properly blended formula. The classical and modern usage is always within a tailored formula that balances Chai Hu’s drying action with appropriate Yin-nourishing or blood-building herbs.

Can I take Chai Hu in pregnancy?

Not first-line. Chai Hu can be used carefully in specific pregnancy contexts under specialist supervision, but is not used routinely.

Prefer to be treated from home? Chinese herbal medicine online consultations are available throughout the UK and worldwide. After a full video consultation, Dr (TCM) Attilio D'Alberto formulates a bespoke herbal prescription and posts your Chinese herbs directly to your door.