Stemona sessilifolia (Miq.) Miq.; Stemona japonica (Bl.) Miq.; Stemona tuberosa Lour. (Stemonae Radix)
Nature and flavour. Sweet and bitter, slightly warm; Lung system.
Traditionally classed as moistening the Lung and stopping cough, and as killing parasites. The cough use spans new and long-standing cough, whooping cough and the cough recorded in consumptive illness; the drug is one of the few in this category also recorded for parasites, classically used externally against head lice and body lice and against pinworm. Preparations in the classical literature include the honey-processed root, which is the form recorded for chronic cough, and the crude drug in decoction or tincture for external parasiticidal use. Traditionally it is described as moistening rather than drying, which is why it appears on both ends of a lingering cough.
性味归经。甘、苦，微温；归肺经。
传统归类为润肺止咳、杀虫灭虱。止咳方面，新咳、久咳、百日咳以及古籍所载劳瘵咳嗽均在记载之内；本品是本类中少数兼记杀虫的一味，古籍外用治头虱、体虱及蛲虫。传统炮制有蜜炙百部，久咳多用蜜制品；外用杀虫则多用生品煎液或浸液。传统认为本品润而不燥，故久咳新咳两端皆可出现。
百部所含生物碱是须谨慎的原因。文献记载内服中毒，表现为恶心呕吐、腹部不适、头晕、呼吸困难与惊厥，重症可致呼吸抑制；这类报告是本品不宜自行使用的理由。外用同样有风险：涂于头皮的制剂具刺激性、不用于破损皮肤、绝不可入口 —— 儿童误饮灭虱制剂是明确记载的中毒途径。婴幼儿使用须有专业指导。孕期与哺乳期安全性未确立。三种法定来源种之间、以及与地方习用百部属品种之间的混淆是实际存在的标签问题，购买时应认明品种，而不是只买「百部根」。