Saw Palmetto in Prostadine: What the Trials Found

Saw palmetto is unusual among the nine ingredients because it has been tested at scale, and the verdict has been consistent.

The first large trial enrolled 225 men aged 50 or older. They took 160 mg of extract twice a day (320 mg in total) or a placebo for a year, and the symptom index did not differ between groups (Bent et al., NEJM 2006). A second trial, called CAMUS, enrolled 369 men for 72 weeks, raised the dose in steps up to 960 mg a day, and again found no advantage over placebo (Bent et al., NEJM 2006).

The Cochrane group then pooled the evidence. Their 2023 review covers 27 randomized trials with 4,656 men, 19 testing saw palmetto alone and 8 testing combination herbal products. They concluded that saw palmetto alone provides little to no benefit for lower urinary tract symptoms, and that side effects were about the same as placebo (Cochrane review, saw palmetto 2023). They were less certain about combination products, which is the category Prostadine falls into.

If you are choosing a supplement because saw palmetto is on the label, the research gives you a reason to look elsewhere for the benefit. If you are choosing for other reasons and have no medicines that clash, the herb is not a safety worry on its own.

See how it sits with the other eight lines on the ingredients page, or read what prostate medicines are known to do on the medicines page.

1. Serenoa repens for the treatment of lower urinary tract symptoms due to benign prostatic enlargement. Franco JVA, Trivisonno L, Sgarbossa NJ, et al. (Cochrane Database Syst Rev, CD001423), 2023.Published 22 June 2023, searched to September 2022: 27 randomized trials with 4,656 men (19 saw palmetto alone versus placebo, 8 combination herbal products). Saw palmetto alone provides little to no benefit for men with lower urinary tract symptoms from benign prostatic enlargement; adverse events were about the same as placebo. The review is less certain about combination products.
2. Saw Palmetto: Usefulness and Safety. National Center for Complementary and Integrative Health (NIH), 2025.NCCIH concludes saw palmetto is probably not helpful for BPH. A 2023 review of 27 studies found little or no benefit; two NIH-funded trials (one at a standard dose, one at up to three times the usual dose) did not improve symptoms. Well tolerated in studies up to 3 years; mild side effects may include digestive symptoms, dizziness and headache. May be unsafe in pregnancy or breastfeeding. Does not appear to affect PSA readings. A 2022 review of five studies found no significant benefit for chronic prostatitis/pelvic pain.
3. Saw Palmetto for Benign Prostatic Hyperplasia. Bent S, Kane C, Shinohara K, et al. (N Engl J Med 354:557-566); with Barry MJ et al., JAMA 2011;306:1344-1351, 2006.The publisher page could not be loaded for this review, so this entry rests on the published abstracts. NEJM 2006: 225 men aged 50 or older, one year, 160 mg of saw palmetto extract twice a day (320 mg a day) versus placebo, no difference in the AUA Symptom Index. JAMA 2011 (CAMUS): 369 men, 72 weeks, 320 mg a day raised stepwise to 960 mg, no better than placebo. These are the usual reference doses for saw palmetto research.