Cynanchum atratum Bunge (C. atratum) and Cynanchum versicolor Bunge (C. versicolor) are two related species that have been used as "Baiwei" (Cynanchi Atrati Radix Et Rhizoma) in traditional medicine in China and other Asian countries for a long time. However, to date, no comprehensive review of C. atratum and C. versicolor has been published. This review provides a comprehensive summary on the botany, phytochemistry, traditional uses and pharmacology of Baiwei; The authors focus especially on the revision of errors in previous articles and reviews, updating information and providing a comparison of C. atratum and C. versicolor. Furthermore, current research reveals significant disparities in the chemical composition and pharmacological effects between C. atratum and C. versicolor. Up to November 2023, 178 compounds have been isolated from C. atratum and C. versicolor, including C₂₁ steroids, acetophenones, alkaloids and volatile oils. These compounds and extracts have been proven to exhibit significant pharmacological activities, including anti-inflammatory, anti-tumor, anti-virus, anti-fungal, memory-enhancing and anti-pyretic action, immune modulatory effects, reducing blood lipid, inhibition of melanin production, and anti-parasitic effects. Therefore, this review presents new insights into these two herbs used as "Baiwei" and further study is warranted to enhance their clinical application.

Key words: Cynanchum atratum, Cynanchum versicolor, C₂₁ steroids, Antofine, Pharmacology