Clears Damp-Heat and resolves jaundice - the classic chief herb for bright yellow Yang-type jaundice with dark urine, abdominal fullness, greasy coating, and Liver-Gallbladder damp-heat, especially when paired with Zhi Zi and Da Huang.
Drains Damp-Heat from the Liver and Gallbladder while promoting urination - used for dysuria, edema, bitter taste, chest oppression, and febrile damp-heat patterns that need both biliary and urinary drainage.
Relieves exterior-level damp-heat - selected for warm-damp or summer-damp presentations with fever, body aches, poor appetite, and oppression of the chest and epigastrium.
Clears Damp-Heat from the skin - extended to eczema, urticaria, oozing sores, and itchy lower-body lesions when Damp-Heat manifests in the exterior tissues.
Secondary Actions
The spring-harvested young shoots are classically preferred, reflecting the old warning that useful Yin Chen later becomes little more than coarse Artemisia stalk once the season passes.
It can be adapted for both Yang and Yin jaundice, but only when the formula context matches the pattern; Yin Chen alone is not a deficiency jaundice tonic.
Classic Formulas
Yin Chen Hao Tang (茵陈蒿汤) - from Shang Han Lun, the classic three-herb jaundice formula in which Yin Chen is the chief herb clearing Damp-Heat from the Liver, Gallbladder, intestines, and urine.
Gan Lu Xiao Du Dan (甘露消毒丹) - epidemic damp-heat formula using Yin Chen to vent Damp-Heat and reduce jaundice, fever, and chest oppression.
Zhen Gan Xi Feng Tang (镇肝熄风汤) - a later formula where Yin Chen serves as an assistant to smooth Liver heat and support downward drainage in complex Liver-Yang excess patterns.
Classical References
Shen Nong Ben Cao Jing is repeatedly cited in later reviews as the earliest classic source for Yin Chen Hao's use in jaundice and hepatic disorders.
The long-standing aphorism 'in the second month it is Yin Chen, in the fifth month it is firewood' highlights the classical insistence on young spring material for best activity.
IMPORT NOTE: the source stub listed the pinyin as Chen Hao, but mainstream TCM sources identify the standard drug here as Yin Chen, with Yin Chen Hao preserved separately as the fuller synonym in herb #186.
Modern Research
Active Compounds
Scoparone (coumarin) - the best-known marker constituent associated with choleretic, anti-inflammatory, and hepatoprotective activity
Chlorogenic acid and related caffeoylquinic acids (phenolic acids) - antioxidant and anti-inflammatory polyphenols abundant in the aerial parts
Capillarisin (chromone/flavonoid-related constituent) - a signature compound discussed in hepatobiliary research on Yin Chen
Scopoletin and isoscopoletin (coumarins) - bioactive metabolites linked to anti-inflammatory and liver-focused pharmacology
Polysaccharides - increasingly studied for gut-liver and cholestasis-modulating effects
Studied Effects
Review literature describes broad choleretic, anti-inflammatory, antioxidant, antiviral, antifibrotic, and antisteatotic activity, which maps closely to Yin Chen's long-standing use in liver and jaundice disorders (PMID 26366183).
Phytochemical anti-HBV research isolated multiple Artemisia capillaris constituents that inhibited HBsAg, HBeAg, and HBV DNA replication in HepG2.2.15 cells (PMID 24685503).
Aqueous Artemisia capillaris extract protected against bile-duct-ligation-induced liver fibrosis in rats, supporting the herb's modern antifibrotic relevance (PMID 23298556).
Artemisia capillaris polysaccharide alleviated cholestatic liver injury in mice through gut-microbiota modulation and Nrf2 signaling activation, strengthening the mechanistic case for cholestasis support (PMID 38447617).