I. A small palm tree, Sabal serrulata, native to Southeastern US and Carribean; extract is prepared from the berries of the tree, though other sources give the botanical name as Serenoa repens!

II. Saw palmetto extract for BPH

  1. Contains various esterified steroids which may be the active components, e.g. beta-sitosterol
  2. Mechanism of action is unclear; inhibition of 5-alpha-reductase has been proposed but not confirmed as of 1998
  3. Improvement in sx (though not using standard sx scores) were seen in 6 and increase in urinary flow rates were seen in 5 of 7 small, short-term (< 3mos) double-blind, randomized, controlled trials with durations of up to 3mos.
  4. 1098 men w/BPH randomized to Permixon (a hexane extract of saw palmetto) 160mg BID vs. finasteride 5mg QD; at 6mos; both groups had decreases in International Prostate Sx score and improved quality of life and peak urinary flow rates with no sig. diff. between the groups; small but statistically sig. greater incidence of worsening in sexual function w/finasteride (Prostate 29:231, 1996, cited in AMA rvw)
  5. 200 men w/BPH randomized to beta-sitosterol 20mg TID (derived from South African star grass, Hypoxis rooperi, not saw palmetto) vs. placebo. Sig. better improvement in sx scores, peak urinary flows, and residual volume at 6mos w/beta-sitosterol group than w/placebo. (Lancet 345:1529, 1995, cited in AMA rvw)
  6. Side effects noted include HA, nausea, and dizziness; no lab test abnormalities noted in 2 studies cited above
  7. Meta-analysis of 18 randomized trials in total 2939 pts for mean study duration of 9wks found that c/w placebo, Saw Palmetto ass'd with sig. decrease in sx and increase in peak urine flow with side f/x comparable with placebo and less than finasteride (JAMA 280:1604, 1998)
  8. In a study in 225 men with mod-severe sx of BPH randomized to saw palmetto extract 160mg BID vs. placebo, over 1y, there were no sig. diffs between the groups in mean AUA sx scores or peak urinary flow rate (NEJM 354:557, 2006--JW)

(Source: Alternative Medicine Alert, 1:1, 1997)