Serenoa repens (Saw palmetto) for Lower Urinary Tract Symptoms (LUTS): The Evidence for Efficacy and Safety of Lipidosterolic Extracts. Part I

Abstract

Lower urinary tract symptoms (LUTS) are classically characterized as being related to storage (e.g., frequency, urgency, and nocturia) or flow (e.g., weak stream, intermittency, straining, and incomplete emptying). Conventional prescription medications such as α1-blockers and 5α-reductase inhibitors are used to treat progressive LUTS in men. Due to the adverse events associated with these prescription drugs, many patients with mild-to-moderate LUTS may decide to initiate treatment with non-prescription medications and/or dietary supplements. The lipidosterolic extract of Serenoa repens (LSESr), at a recommended daily dose of 320 mg/day, has been the focus of numerous peer-reviewed studies and review articles concerning the treatment of LUTS, from the first publication in 1983 by Boccafoschi to the most recent publication in 2021 by Russo. Although it seems improbable that the beneficial effect of LSESr reflects a placebo effect given the consistent degree of efficacy comparing various studies published in different countries over a span of almost 40 years, this has been the prevailing impression stemming from essentially three publications in the Western medical literature. In addition, despite publications reporting findings of almost identical efficacy using LUTS endpoints such as the International Prostate Symptom Score (IPSS), the quality of life score (QoL), and the peak urinary flow (Qmax) in comparing LSESr with the α-blocker tamsulosin or the 5α-reductase inhibitor finasteride, and despite the recognized acceptance of the hexane lipidosterolic extract product (Permixon®) as an herbal medicine in Europe showing value in the treatment of LUTS, the use of LSESr remains controversial in the US. Contributing to such an opposing view in the US are the wide variability in quality, composition, and dosage of Serenoa products, the commercial prevalence of dried berry powder supplements, and the lack of awareness of a standardized Serenoa phytotherapy lipidosterolic profile. Can the controversy over the efficacy of LSESr in the context of LUTS be resolved? By understanding the main literature that has led to clinical practice guidelines for Serenoa repens for LUTS in Europe and the US, and by an in-depth analysis of the totality of the clinical literature concerning dose, extraction method, and quality of the Serenoa product used, it should be possible to answer this question. Given the extent of this global analysis, this report is presented in three sections. Part I introduces LUTS. What are the demographics of LUTS? What symptoms are assessed by LUTS, and how do we quantify LUTS? Why would a non-prescription item be a valuable consideration in LUTS treatment versus other treatment options? What is basic information about Serenoa repens, and what defines a standardized LSESr product? What are the published trials that have affected the acceptability of Serenoa repens in the treatment of LUTS? Finally, a major portion of Part I discusses the four major reviews of Serenoa repens versus LUTS that have influenced how it is accepted in the USA, in Europe, and in other parts of the world. Part I, therefore, lays the groundwork and is foundational for the important findings relating to LUTS and Serenoa repens that will be presented as Parts II and III in subsequent review articles.