Capillary Wormwood (Yin Chen Hao)

Traditional Use

Primary Actions

• Clears Damp-Heat and treats jaundice - Yin Chen Hao is the archetypal herb for bright yellow Damp-Heat jaundice, dark urine, and biliary obstruction patterns in the Liver and Gallbladder network.
• Promotes urinary and biliary drainage - used for dysuria, edema, abdominal fullness, and febrile damp obstruction when the pathogenic load must be led out through both urine and stool.
• Vents damp-warm pathogens from the exterior and middle burner - added for fever, poor appetite, nausea, body heaviness, and chest oppression in seasonal damp-heat disorders.
• Clears Damp-Heat from the skin - applied to itchy, oozing, or inflamed skin disorders such as eczema, urticaria, and damp-heat sores.

Secondary Actions

• Yin Chen Hao is the fuller classical name of the same drug commonly shortened to Yin Chen, and both names point to the young aerial parts of Artemisia capillaris or Artemisia scoparia used in spring.
• Formula context matters: it shines in Damp-Heat and bile-stasis patterns but should not be mistaken for a general-purpose tonic for pale deficient jaundice.

Classic Formulas

• Yin Chen Hao Tang (茵陈蒿汤) - from Shang Han Lun, pairing Yin Chen Hao with Zhi Zi and Da Huang to clear jaundice through the Liver, Gallbladder, bowel, and urine simultaneously.
• Gan Lu Xiao Du Dan (甘露消毒丹) - a damp-warm and epidemic-toxin formula where Yin Chen Hao helps vent Damp-Heat, reduce jaundice, and relieve chest oppression.
• Yin Chen-centered damp-heat jaundice modifications - later formula traditions repeatedly preserve Yin Chen Hao as the chief herb whenever biliary damp-heat remains the central pattern.

Classical References

• Chinese pharmacopoeia and modern reviews note that Yin Chen may refer to the young aerial parts of either Artemisia scoparia or Artemisia capillaris, preserving a long-standing dual-botanical tradition under one medicinal identity.
• The old seasonal saying that February Yin Chen becomes useless by May explains why classical physicians insist on early spring harvest for the true medicinal material.
• SYNONYM NOTE: this record keeps the fuller name Yin Chen Hao, while herb #185 preserves the shorter Yin Chen form; both are spreadsheet-retained synonym records rather than separate species-level medicines.