Anxiety reduction is the best-known use case for kava. Clinical studies indicate that standardized kava preparations (210–300 mg, containing either 30 or 70% kavalactones depending on standardization used) could be a safe and effective alternative to benzodiazepines for the treatment of short-term anxiety.[1][2][3][4][5][6][7][8][9] Clinical evidence still appears to be mixed, however, regarding the effectiveness of kava for generalized anxiety disorder (GAD). Trials of standardized preparations (300–400 mg/day) have had the strongest results, possibly through effects on vasovagal response.[10][11][12] Similar studies using different doses and/or preparations do not support kava use for GAD.[13][14][15]
Kava has also been studied for other anxiety disorders. People experiencing postmenopausal anxiety saw reductions in symptoms when hormone replacement therapy was combined with lower doses (100 mg/day) of kava extract for periods of three to six months.[16][17] Clinical studies including both menopausal and perimenopausal women similarly saw improvements in menopause-related anxiety with kava extract (100–300 mg/day over 8 to 12 weeks) compared to a control.[18][19]
Finally, there is some indication that kava can boost mood in individuals without apparent health conditions. One trial noted that a single 300 mg dose of kava extract (containing 90 mg kavalactones) resulted in mood boosts that occurred within about an hour.[20]