Saw Palmetto:
Men with enlarged prostates (medically known as benign prostatic hyperplasia, or BPH) often experience difficulty with urinary flow, increased frequency and urgency of urination, and a fullness of the bladder after urination. It has been believed that saw palmetto dietary supplements provide mild to moderate improvement in symptoms of prostate enlargement. However, the evidence of saw palmetto's benefit is conflicting and recent studies have failed to show any benefit over placebo.

A large and well designed study published in 2011 showed no greater improvement with saw palmetto extract versus placebo (Barry, JAMA 2011). As an extra measure, that study used the standard dose of saw palmetto (320 mg per day of extract standardized to 85% to 95% fatty acids) as well as twice and three times the dose, each for 24 weeks. None showed a significant benefit. A  large study published in 2006 also did not show a benefit with different saw palmetto extract in men with moderate to severe symptoms. Only more limited studies have shown benefit in men with mild symptoms and that saw palmetto may be as effective as the prescription drug finasteride (Proscar), but with fewer side effects. Alpha-blockers, meanwhile, may be more effective than saw palmetto.
 
Beta-sitosterol:
Most studies of beta-sitosterol, although not all, have found significant improvement in perceived symptoms of BPH and in urine flow rate. In addition, benefits seem to persist for months after treatment according to a follow up study that looked at men one year after treatment (Berges 2000). Like the BPH drug finasteride (Proscar), beta-sitosterol may inhibit 5-alpha-reductase activity in the prostate.
At a much higher dosage and in combination with other sterols, beta-sitosterol can also lower total cholesterol and LDL cholesterol levels when these supplements are consumed with meals In this case, beta-sitosterol works in the gut, where it reduces cholesterol absorption.

Our recommendations:
Although neither are known to have harmful side effects, we have known for years that saw palmetto is useless. I would recommend a trial of Beta-sitosterol to see if it works.
As with all supplements, please remember that they are NOT under FDA control and may not contain the exact amount of ingredients as listed on the label and may contain contaminates.