Bupleurum chinense ( Chai Hu ), a pivotal herb in Traditional Chinese Medicine (TCM), delivers five primary actions: releasing the exterior to reduce fever, soothing liver qi stagnation, lifting yang qi, resolving liver depression, and correcting qi collapse.  

 Core Therapeutic Actions  

1. Releases Exterior & Reduces Fever 

   - Properties: Bitter, acrid, slightly cold.  

   - Indications: Early-stage fever from wind-heat invasion , body aches, chills.  

   - Mechanism: Disperses pathogenic factors from the body's surface.  

2. Regulates Liver Qi & Relieves Stagnation   

   - Applications: Emotional suppression, irritability, rib-side pain from liver qi constraint (gān yù qì zhì).  

   - Classic Formula: Xiao Yao San ( Free Wanderer Powder).  

3. Lifts Yang Qi

   - Action: Replenishes and elevates depleted yang qi (e.g., in chronic fatigue or organ prolapse).  

   - Key Pairing: With astragalus (Huáng Qí) and cimicifuga (Shēng Má) in Bu Zhong Yi Qi Tang .  

4. Resolves Liver Depression 

   - Synergy: Restores smooth qi flow, alleviating distension, sighing, and menstrual irregularities.  

5. Corrects Qi Collapse  

   - Focus: Middle jiao qi deficiency with symptoms like rectal/uterine prolapse.  

 Pharmacological Insights  

- Saikosaponins: Modulate immune response and exhibit anti-inflammatory effects.  

- Hepatoprotective: Enhances liver detoxification and bile secretion.