Background: The efficacy of traditional plant-based treatments, such as chamomile and sumac, for uterine fibroids-associated menstrual symptoms is not known. In this randomized trial, we evaluated the efficacy and safety of sumac and chamomile in reducing the duration and intensity of menstrual bleeding and pain associated with uterine fibroids. Experimental approach: This triple-blind, three-arm, randomized, placebo-controlled trial was conducted among 154 women with uterine fibroids. Participants were randomly assigned to receive either a placebo (n=52), 500 mg of dried sumac powder (n=50), or 500 mg of dried chamomile powder (n=52) every 8 hours from days 1 to 7 of two consecutive menstrual cycles. Generalized Estimating Equations (GEE) were used to analyze repeated measures while accounting for within-subject correlations. Bonferroni correction was applied for post hoc comparisons to adjust for multiple testing. Key results: In the second menstrual cycle, chamomile reduced vaginal bleeding by 20% and bleeding duration by 20%, while sumac reduced bleeding by 14% and duration by 19%. Chamomile also decreased pain intensity by 46% and pain duration by 42%, whereas sumac reduced pain intensity by 45% and duration by 35%. Post-hoc analyses confirmed significant reductions in menstrual bleeding and pain (both intensity and duration) for participants in both groups, with effects more pronounced by the second cycle. Conclusions and implications: The study suggests that chamomile and sumac may serve as effective natural treatments for managing heavy menstrual bleeding and pain associated with uterine fibroids, offering a complementary non-hormonal, non-surgical therapy.