Clears Liver fire and brightens the eyes - Xia Ku Cao is a key herb for red, swollen, painful eyes, headache, and dizziness from ascending Liver fire.
Dissipates nodules and reduces swelling - it is classically used for scrofula, goiter, thyroid nodules, breast lumps, and other hard masses linked to phlegm-fire.
Drains constrained heat and resolves toxicity - traditional use extends to sore throat, hot swellings, and breast carbuncle patterns.
Secondary Actions
Xia Ku Cao is widely consumed as a cooling summer tea in southern China, but medicinal doses for nodules and Liver fire are not the same as casual beverage use.
Among cooling eye herbs, it is especially valued when upward fire and palpable nodulation appear together.
Classic Formulas
Eye-clearing pairings with Ju Hua and Jue Ming Zi - traditional formula lineages use Xia Ku Cao when red eyes and headache reflect rising Liver fire.
Nodule-dissolving lineages pair Xia Ku Cao with Hai Zao and Kun Bu for scrofula, goiter, and phlegm-fire masses.
Single-herb and simple tea preparations are also traditional for summer heat with red eyes and irritability.
Classical References
TCM healing-herb and TCM Wiki materia medica sources describe Xia Ku Cao as bitter, pungent, and cold, entering the Liver and Gallbladder to clear fire and dissipate swelling.
Shen Nong Ben Cao Jing is cited as the earliest major classical source for Xia Ku Cao and emphasizes its use for scrofula, sores, and constrained heat.
Modern Research
Active Compounds
Rosmarinic acid - a key quality-control and anti-inflammatory phenolic compound
Ursolic and oleanolic acids - triterpenes associated with anti-inflammatory and antiproliferative research
Flavonoids such as rutin and quercetin derivatives - antioxidant constituents frequently discussed in reviews
Polysaccharides and phenylpropanoids - additional fractions contributing to immunologic and metabolic study interest
Studied Effects
A 2022 review summarized ethnopharmacology, phytochemistry, quality control, and pharmacologic research on Prunella vulgaris, highlighting anti-inflammatory, antioxidant, and nodule-related use contexts (PMID 35814234).
A 2023 updated overview reviewed botanical, chemical, extraction, and biological-activity data for Prunella vulgaris, reinforcing broad preclinical interest in anti-inflammatory and antimicrobial effects (PMID 37631021).
A 2019 comprehensive review described anti-microbial, anti-cancer, and anti-inflammatory activities for Prunella vulgaris while noting that clinical evidence remains limited (PMID 30864498).