Comparison guide
Saw palmetto or beta-sitosterol for the prostate?
Saw palmetto is the best-known prostate supplement, but its trials consistently show it performs no better than placebo. Beta-sitosterol has a smaller but positive evidence base for urinary symptoms and flow, without shrinking the prostate. Either way, urinary symptoms need a proper diagnosis first.
The options, compared
| Option | Evidence | Best for | The honest note | |
|---|---|---|---|---|
| Saw Palmetto | Limited evidence | Not worth the money | The Cochrane review of 32 trials in 5,666 men found it no better than placebo for symptoms, nocturia or flow, even at double and triple the 320 mg/day dose. Relying on it instead of prescribed BPH treatment risks retention. | View |
| Beta-Sitosterol | Moderate evidence | Mild BPH urinary symptoms | Four short trials at 60–130 mg/day improved IPSS by about 4.9 points and peak flow by 3.91 mL/s, but prostate volume did not change. Capsules are far too low-dose for the cholesterol effect, which needs about 2 g/day of plant sterols. | View |
Our verdict
If you want a supplement for mild BPH symptoms, beta-sitosterol at 60–130 mg/day has moderate evidence; saw palmetto has none at any dose tested. Neither shrinks the prostate or replaces alpha-blockers or 5-alpha-reductase inhibitors when symptoms progress, and anyone with sitosterolaemia must avoid beta-sitosterol.