Trial evidence
Saw Palmetto for Enlarged Prostate: What Large Trials Found
Saw palmetto for enlarged prostate has been tested in large trials, and the results are not encouraging. A 2023 Cochrane review of 27 trials found little or no difference in urinary symptoms compared with placebo. Two big U.S. trials, one using three times the usual dose, also found no benefit. A doctor should check urinary symptoms.
Written by the Protoflow label deskUpdated · 4 min read
Does saw palmetto work for an enlarged prostate?
In the best trials, no. Saw palmetto made little or no difference to urinary symptoms from an enlarged prostate.
The 2023 Cochrane review pooled 27 trials with 4,656 men. In the lower-risk studies it found little to no difference in symptom scores at 3 to 6 months, and adverse events were close to placebo (Cochrane review, Franco 2023). NCCIH calls the herb "probably not helpful" for these symptoms (NCCIH, Saw Palmetto).
Some combination products showed small differences at 12 to 24 weeks, but the certainty was low. Protoflow is a 14-ingredient blend, and no trial has tested it. Learn more on our saw palmetto ingredient page.
- 2006
225 men took 160 mg twice a day for a year. Symptom scores, urine flow and prostate size were no different from placebo (Bent et al., NEJM 2006).
- 2011
369 men took up to three times the standard 320 mg a day. Symptoms improved 2.20 points on the herb and 2.99 on placebo (Barry et al., JAMA 2011 (CAMUS)).
- 2023
Cochrane pooled 27 trials and found little or no difference (Cochrane review, Franco 2023).
Why do some men say saw palmetto helped their prostate?
Placebo groups improved too. In the 2011 trial, men on dummy capsules lost nearly 3 points on the symptom scale (Barry et al., JAMA 2011 (CAMUS)).
Urinary symptoms rise and fall on their own, and men who join a study often feel better just from being watched. A personal story can be honest and still not show the herb did anything. Without a placebo group, you cannot tell.
What the trials support
- Side effects were similar to placebo
- PSA readings did not change
What they do not support
- Better flow or fewer symptoms
- A smaller prostate
What should you do about an enlarged prostate besides saw palmetto?
See a doctor to find the cause. A weak stream, straining or waking at night to pee can come from an enlarged prostate, an infection, diabetes or prostate cancer.
About 5 to 6 percent of men aged 40 to 64 have an enlarged prostate, and 29 to 33 percent of men 65 and older (NIDDK, Prostate Enlargement (BPH)). Doctors can test, and treatments exist. Self-help from the NHS includes cutting alcohol and caffeine and limiting fluids before bed (NHS, Enlarged Prostate). See our prostate basics guide for the full picture.
Unable to pee, blood in the urine, fever with painful peeing, or severe lower belly pain.
Keep taking prescribed medicine, and ask your doctor or pharmacist before adding any supplement.
Protoflow: from $1.63 a day60 capsules a bottle · packs of 2, 3 or 6 · 60-day money-back guarantee
See packsHow much saw palmetto is in a prostate supplement like Protoflow?
Protoflow holds 84.5 mg of saw palmetto fruit per two capsules. The big trials used 320 mg a day or more, so that is about a quarter of the standard trial dose.
| Source | Per day |
|---|---|
| 2006 trial | 320 mg extract |
| 2011 trial | 320 to 960 mg extract |
| Protoflow label | 84.5 mg fruit |
It is one of 14 actives, all printed. We do not claim it treats an enlarged prostate. Our prostate supplement guide explains how to read any label.
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Prices from the sales page, October 19, 2026 (Protoflow sales page: packs). Two bottles cost $158 plus a small shipping fee. Every pack carries the 60-day money-back guarantee. Check your medicines first.
FAQ
Saw palmetto and prostate questions
01Does saw palmetto shrink an enlarged prostate?
No. In the 2006 year-long trial, prostate size did not differ from placebo, and neither did symptom scores or urine flow. No source we hold shows saw palmetto reducing prostate size.
02Should I try saw palmetto before seeing a doctor about a weak stream?
No, see the doctor first. A weak stream can come from an enlarged prostate, an infection, diabetes or prostate cancer, and the right test depends on the cause. A supplement can delay that answer.
03Is saw palmetto the same as a prostate medicine?
No. It is a dietary supplement, and FDA does not approve supplements before sale. Prescribed prostate medicines are a separate matter, so never stop one without your doctor's advice.
Who wrote this
Written and reviewed by
Pages built from the Protoflow label, the sales page and linked NIH, FDA, FTC, NHS and peer-reviewed sources.
Last updated . Learn about our editorial standards and how we check reviews. This website is run by Goprotoflow, a licensed U.S. retail desk for Protoflow, not by the manufacturer or by PhytoThrive Labs. We earn money when you buy through our order links.
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