Unfortunately, studies on most nutritional supplements, such as Saw Palmetto, are not as robust as the average clinical research study. From what I have reviewed in the literature, we still don't know the exact mechanism of Saw Palmetto, and the studies are all fairly small. The doses range from 320 to 960 mg/day, but did not prove to be much more effective than a placebo.

So, as of today, Saw Palmetto is not a truly proven treatment for benign prostatic hypertrophy (BPH). Variability in the quality and purity of available products limits the ability of a clinician to provide sound advice to the patient. If patients do choose to take Saw Palmetto, a product should be chosen that meets specific quality criteria

Small studies of Beta-Sitosterol showed some symptom improvement, but not enough to recommend it as a treatment option for BPH either.