Subgroup analysis did not reveal any results that differed from the main outcomes. The only adverse events that were significantly different between the 2 groups related to physical injury or trauma, which were unlikely to be due to the intervention.1
By using the same symptom scoring system (AUASI) as many studies in the previous Cochrane reviews, Barry et al were able to compare their findings with those of other high-quality studies with similar methodologies and outcome measures. Despite using an even higher dose of the extract, the results of this trial are remarkably consistent with previous conclusions: Saw palmetto is not an effective treatment for symptoms associated with BPH. Moreover, this trial had a broad base of participants similar to the population in a primary care practice, including patients who would typically choose a natural remedy for LUTS.1
WHAT’S NEW: We now have answers to queries about saw palmetto
This trial is the first to compare higher doses of saw palmetto with placebo to assess a dosage threshold for effectiveness. While the study found no evidence of saw palmetto toxicity even at these higher doses, the extract did not outperform placebo for any measured outcome.1
This high-quality study confirmed the recent series of rigorous studies with negative outcomes by showing that the use of a standard dosage was not a study limitation and that saw palmetto extract is not effective for treating LUTS at any dosage. This trial should substantially affect future guideline recommendations that were limited by methodological concerns in the past.9-11
CAVEATS: In theory, individual preparations could work differently
It is not possible to be absolutely certain that these findings apply to all saw palmetto extract preparations, given the unknown active ingredients and unknown mechanism of action. However, the researchers used a high-quality preparation (a proprietary lipidic ethanolic extract) of saw palmetto at higher doses than the STEP trial and came to a similar conclusion, making it highly unlikely that another preparation would perform differently.
CHALLENGES TO IMPLEMENTATION: There are none
We see no challenges to implementation of this recommendation.
Acknowledgement
The PURLs Surveillance System is supported in part by Grant Number UL1RR024999 from the National Center for Research Resources, a Clinical Translational Science Award to the University of Chicago. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Center For Research Resources or the National Institutes of Health.