Evidence Level
Kava has the strongest evidence base among herbal anxiolytics. The Cochrane review by Pittler & Ernst (2003) analyzed 11 RCTs totaling 645 participants and found kava significantly superior to placebo for anxiety (WMD 3.9 on Hamilton Anxiety Scale). Sarris et al. (2013) confirmed this in a well-designed 6-week RCT showing significant GAD symptom reduction with kavalactones. Regarding safety, the hepatotoxicity concern stems from case reports primarily linked to non-noble cultivars, use of stem and leaf material (not root), and ethanol/acetone extraction methods. Teschke et al. (2012) comprehensively reviewed the liver safety data and concluded that noble cultivar aqueous root extracts have an excellent safety profile, consistent with centuries of traditional Pacific Island use without liver toxicity.