Saw Palmetto
Research Reliability -
A palm berry extract that supports prostate health, urinary function, and hormonal balance in men.
Appetite
Mood
Sleep
Saw Palmetto
Description
Saw palmetto (Serenoa repens) extract is one of the most studied botanical interventions for benign prostatic hyperplasia (BPH), a common condition in men over 50 characterized by urinary symptoms from prostate enlargement. Its primary mechanism involves inhibiting 5-alpha-reductase, the enzyme that converts testosterone to dihydrotestosterone (DHT), which drives prostate cell proliferation. It may also reduce DHT-related hair follicle miniaturization, making it relevant for men concerned about androgenic hair loss. Clinical evidence supports improvements in urinary flow, frequency, and nighttime urination with consistent use.
Effects
First weeks
no felt change
Weeks 4–12
urinary flow and frequency may improve
Ongoing
prostate and DHT-related support
How it Feels
This is a slow, quiet supplement; men taking it for urinary symptoms may notice easier, less frequent trips to the bathroom after a couple of months. There is no acute effect. Consistency over weeks is what matters.
Usage
Entry Dose
160mg
Standard Dose
320mg
Max Dose
640mg
Onset
4–12 weeks (prostate/DHT)
Combinations
Pairs well with
Synergistic
Zinc — zinc supports prostate health and DHT metabolism alongside saw palmetto
Selenium + lycopene — prostate antioxidant stack; complementary protective mechanisms
Stinging nettle root — traditional BPH combination; additive 5-alpha reductase inhibition
Avoid combining
Contraindicated
Finasteride / 5-alpha reductase inhibitors — redundant and potentially additive DHT suppression
Blood thinners — saw palmetto has mild antiplatelet effects; additive bleeding risk
Biomarkers to Track
Subjective
(Daily)
Urinary urgency frequency
Nighttime urination frequency
Urinary flow strength (1–10)
Objective
(Quarterly)
PSA (prostate-specific antigen)
DHT serum level
Urinary flow rate (uroflowmetry)
Very safe. It can lower PSA readings and has mild blood-thinning.
Men should tell their doctor before a PSA test, and blood-thinner users should note the effect.
Not mentioning it before prostate screening, and expecting quick results.
Moderate (some human RCTs)
This Cochrane review found saw palmetto performed no better than placebo for BPH symptoms, even at higher doses. This directly contradicts its popular reputation as a prostate-support supplement.
Tacklind J et al. (2012). Cochrane Database of Systematic Reviews. Meta-analysis (saw palmetto for benign prostatic hyperplasia). PMID: 23235581.