Clears deficiency heat and cools the Blood - classically used for lingering low-grade fever, postpartum or late-stage febrile disease, and steaming-bone or hidden heat patterns arising from yin-blood depletion.
Clears heat from the nutritive level without trapping pathogens - especially valued after febrile disease when heat remains but the patient is already depleted and cannot tolerate harsh draining herbs.
Promotes urination and unblocks painful urinary difficulty - extended to heat-type strangury or fluid obstruction when internal heat agitates the lower burner.
Resolves toxin and benefits the throat - used for sore throat, carbuncles, and toxic swellings when heat toxin combines with blood-level irritation.
Secondary Actions
Bai Wei has the unusual classical niche of treating both deficiency heat and unresolved pathogen patterns, making it useful when yin has been injured but lingering heat remains.
This file keeps the imported English name, but the medicinal identity is the standard root and rhizome Bai Wei rather than a distinct herb called 'blackend swallowwort root.'
Classic Formulas
Bai Wei Tang (白薇汤) - traditional formula lineage for postpartum or deficiency-complicated heat patterns, using Bai Wei to clear hidden heat without overly damaging the weakened patient.
Qian Jin Wei Rui Tang (千金葳蕤汤) - from Qian Jin Fang, where Bai Wei helps address lingering heat and dryness after externally contracted illness in weakened patients.
Classical References
Shen Nong Ben Cao Jing records Bai Wei for violent heat, body heat, and stubborn heat disorders, establishing its role in clearing hidden or chronic heat.
Me and Qi and TCM Wiki describe Bai Wei as bitter, salty, and cold, entering the Liver, Stomach, and Kidney channels and treating deficiency heat, postpartum fever, painful urinary disorders, and toxic swellings.
IMPORT NOTE: The English slug reflects an awkward spreadsheet translation, but the herb itself is the standard medicinal Bai Wei.
Modern Research
Active Compounds
C21 steroidal glycosides such as cynatratosides (steroidal glycosides) - characteristic constituents repeatedly highlighted in Bai Wei phytochemistry
Paeonol-like acetophenones and related phenolics (phenolics) - part of the root's anti-inflammatory and antioxidant chemistry
Cynandione and related benzophenone derivatives (phenolic ketones) - bioactive components studied in Cynanchum atratum extracts
Polysaccharides (polysaccharides) - contribute immunomodulatory and anti-inflammatory research interest
Minor alkaloid and volatile constituents (mixed secondary metabolites) - broaden the modern pharmacologic picture beyond the glycoside fraction
Studied Effects
A 2024 review summarized Bai Wei's phytochemistry, anti-inflammatory, hepatoprotective, antitumor, and immunomodulatory research while linking the data back to its traditional heat-clearing use (PMID 40374443)
Broad pharmacology review work in 2021 similarly emphasized the anti-inflammatory, antioxidant, and fever-related relevance of Cynanchum atratum root constituents (PMID 34662666)
Cynatratoside C inhibited inflammatory mediators in vitro and ameliorated experimental colitis in vivo, offering a mechanistic correlate for the herb's heat-clearing and toxin-resolving profile (PMID 29113806)
Bai Wei extract reduced nonalcoholic fatty liver disease progression in a high-fat-diet model through AMPK activation and lipogenesis inhibition, expanding modern metabolic interest in the herb (PMID 35011585)
Loose stools or severe weakness of the middle burner not accompanied by lingering Heat
Cautions
Because Bai Wei is cold and clears hidden heat, it should be matched to true heat or heat-toxin patterns rather than used generically for fatigue or postpartum weakness alone
The herb is often chosen precisely because the patient is depleted, so dose and formula balance matter to avoid overcooling digestion
MSK page not found - drug interaction data not available from Memorial Sloan Kettering integrative medicine database