In the limited studies done thus far comparing SP to alpha-blockers, SP has often, but not always, shown comparable benefits. When 41 men with BPH were randomized to receive SP or prazosin for 12 weeks, improvements in urinary frequency and urinary flow rate were slightly better for prazosin, but otherwise were very similar.

In one interesting study with 358 patients, alfuzosin, an alpha-blocker, was compared to Pygeum. The alpha-blocker worked a little bit better, but overall the symptom reduction in both groups was alike. In another study, alfuzosin was compared to SP. Sixty-three patients with BPH were tested in a double-blind manner for a three-week period using alfuzosin 2.5 mg three times a day compared to SP 160 mg twice a day. There were clear differences between the two treatments. The group on alfuzosin showed statistically significant improvement in the ability to urinate, and had a better peak flow rate (the speed of the urine coming out of the bladder). The results of this study make sense since alpha-blockers are known to act very quickly and the effects of SP would take longer to notice. In the short term, alpha-blockers, as a rule, are probably more effective than single herbs. However, the combination of two or more herbs working with a different mechanism could, in the long run, potentially be more beneficial than alpha-blockers used alone. More research is needed to evaluate this proposal.