"...Pygeum africanum provided a moderately large improvement in the combined outcome of urologic symptoms and flow measures as assessed by an effect size defined by the difference of the mean change for each outcome divided by the pooled standard deviation for each outcome (-0.8 SD [95% confidence interval (CI), -1.4, -0.3 (n=6 studies)]). Men using Pygeum africanum were more than twice as likely to report an improvement in overall symptoms (RR=2.1, 95% CI = 1.4, 3.1). Nocturia was reduced by 19%, residual urine volume by 24% and peak urine flow was increased by 23%. Adverse effects due to Pygeum Africanum were mild and comparable to placebo..."
that's from the NIH
also:
Beta-sitosterol has been shown effective for symptomatic BPH