Yin Chai Hu 银柴胡 — Chinese Herbal Medicine

Yin Chai Hu (银柴胡) At a Glance

• Herb: Yin Chai Hu
• Chinese name: 银柴胡 (Yin Chai Hu)
• Latin name: Stellariae Radix
• Nature: Cold
• Taste: Bitter, Sweet
• Meridian: Liver
• Category: resolve deficient heat

Despite sharing “Chai Hu” in its name, Yin Chai Hu is a distinct herb — the root of Stellaria dichotoma — historically confused with Bupleurum yet valued in its own right since the Ming dynasty, when Li Shizhen clarified its identity in the Bencao Gangmu. Its cold, sweet-bitter nature makes it a gentle yet reliable agent for clearing heat that rises from deficiency rather than excess. Clinically, it is indispensable for afternoon tidal fever, night sweats, and the emaciation fevers seen in chronic wasting conditions.

Actions & Therapeutic Effects

• Clears deficiency heat — reduces afternoon tidal fever (午後潮熱) and low-grade persistent fever arising from Yin deficiency without consuming fluids
• Cools steaming bone disorder — addresses 骨蒸勞熱 (gǔ zhēng láo rè), the deep feverish sensation felt within the bones in consumptive disease
• Resolves childhood nutritional impairment fever — clears 疳熱 (gān rè) in children with Spleen deficiency and chronic malnourishment
• Stops sweating from deficiency heat — used when night sweats accompany the Yin-deficient fever pattern
• Cools blood without strongly moving it — contrasts with Chai Hu, which courses Liver Qi; Yin Chai Hu acts on the blood level without dispersing

Clinical Applications in TCM

• Yin deficiency tidal fever with night sweats and emaciation — paired with Qing Hao (青蒿), Di Gu Pi (地骨皮), and Zhi Mu (知母) in formulas such as Qing Gu San (清骨散)
• Steaming bone disorder in Liver and Kidney Yin deficiency — combined with Bie Jia (鱉甲) and Qin Jiao (秦艽) to clear deep latent heat
• Childhood nutritional fever (疳熱) — used with Hu Huang Lian (胡黃連) and Ji Nei Jin (雞內金) to clear heat while supporting digestion
• Chronic low-grade fever in post-febrile illness — combined with Mu Dan Pi (牡丹皮) and Sheng Di Huang (生地黃) to nourish Yin and resolve residual heat
• Consumptive cough with afternoon fever — paired with Bai Wei (白薇) and Mai Men Dong (麥門冬) to moisten Lung and clear heat

Precautions & Safety

• Dosage: 3–9 g in decoction; up to 15 g in severe deficiency heat patterns; no special preparation required
• Contraindicated in exterior heat conditions, excess-type fever, or any pattern without clear Yin deficiency — it will not resolve exterior pathogens and may trap heat
• Use cautiously in Spleen-Stomach deficiency with loose stools; the cold nature can aggravate digestive weakness — combine with Bai Zhu or Chen Pi if needed
• Not to be substituted for Chai Hu (柴胡) — different herb, different mechanisms; combining them requires deliberate formula design

Classical TCM Formulas

• Qing Gu San (清骨散): Yin Chai Hu, Zhi Mu, Di Gu Pi, Huang Lian, Qin Jiao, Bie Jia, Qing Hao, Gan Cao — clears bone-steaming tidal fever from Yin deficiency. Source: Zheng Zhi Zhun Sheng.
• Yin Chai Hu San (银柴胡散): Yin Chai Hu, Huang Qin, Bai Wei, Qing Hao — for deficient-Heat with afternoon fever. Source: Classical simple formula.
• Qing Re Yang Yin Tang (清热养阴汤): Sheng Di Huang, Xuan Shen, Mai Men Dong, Yin Chai Hu, Di Gu Pi, Zhi Mu — severely deficient Yin with tidal fever and night sweats.

Herb Combinations

• Yin Chai Hu (银柴胡) + Huang Lian (黄连) + E Jiao (阿胶): the Qing Hao Bie Jia Tang-type combination — clears deficient Heat and nourishes Yin. Source: Wen Bing Tiao Bian.
• Yin Chai Hu (银柴胡) + Di Gu Pi (地骨皮) + Zhi Mu (知母): clears bone-steaming Heat (骨蒸潮热) from Yin deficiency. Source: Classical deficient-Heat combinations.
• Yin Chai Hu (银柴胡) + Bie Jia (鳖甲) + Qing Hao (青蒿): nourishes Yin and clears deficient Heat — the core of Qing Hao Bie Jia Tang.
• Yin Chai Hu (银柴胡) + Sheng Di Huang (生地黄) + Bai Shao (白芍): clears deficient Heat while nourishing Yin and Blood for night sweats and tidal fever.

Pharmacology & Research

Anti-pyretic: α-spinasterol suppresses central prostaglandin E2 synthesis, reducing fever via hypothalamic modulation.
Anti-inflammatory: stellaric acid saponins inhibit NF-κB activation, lowering IL-6 and TNF-α in chronic inflammatory states.
Immunomodulatory: polysaccharide fractions enhance T-lymphocyte proliferation, supporting immune regulation in deficiency conditions.
Hepatoprotective: triterpenoid saponins reduce ALT/AST elevation and protect hepatocytes against oxidative stress-induced apoptosis.

Classical Descriptions

• “銀柴胡，退熱而不苦泄，理陰而不升騰，與柴胡迥別。” — Bencao Congxin (本草從新), Wu Yiluo, Qing dynasty. (“Yin Chai Hu withdraws heat without bitter draining, regulates Yin without ascending — entirely different from [Bupleurum] Chai Hu.”)