Saw palmetto, derived from the fruit of the Serenoa repens plant, is a commonly used herbal supplement with multiple recognized benefits, particularly for men's health and urinary symptoms.

Primary Uses and Benefits

1. Benign Prostatic Hyperplasia (BPH):

   • Saw palmetto is primarily known for its use in treating symptoms of BPH, a common condition in older men characterized by prostate enlargement¹². It may improve urinary symptoms such as urgency, hesitancy, and nocturia (frequent nighttime urination) by inhibiting the enzyme 5-alpha-reductase, which converts testosterone to dihydrotestosterone (DHT), a hormone that contributes to prostate growth¹.

2. Antiandrogenic Properties:

   • The supplement exhibits antiandrogenic effects by inhibiting DHT formation and binding to androgen receptors, which is also why it has been used to support hair growth in conditions like androgenetic alopecia³⁴.

3. Urinary Symptoms in Women:

   • Some studies have suggested benefits of saw palmetto in alleviating lower urinary tract symptoms (LUTS) in women, such as improving bladder capacity and reducing the frequency of urination⁵.

Mechanisms of Action

• Inhibition of 5-alpha-reductase: This enzyme is responsible for converting testosterone into DHT. By inhibiting this enzyme, saw palmetto reduces DHT levels, which are implicated in both prostate growth and hair loss¹³.
• Receptor Binding: Saw palmetto extracts may bind to muscarinic receptors and vanilloid receptors, leading to amelioration of urinary symptoms⁵.

Side Effects and Safety

• Saw palmetto is generally well-tolerated. Common but mild side effects include dizziness, headache, nausea, vomiting, constipation, and diarrhea. Randomized controlled trials suggest that these side effects are no more frequent than with placebo¹².

Summary

The primary uses of saw palmetto are for the management of BPH symptoms and its potential benefits on hair growth in androgenetic alopecia due to its antiandrogenic effects. It has also shown some promise in treating urinary symptoms in both men and women. Despite its popularity, more large-scale, high-quality clinical trials are needed to confirm its efficacy in various conditions.

Footnotes

1. Chua T, Eise NT, Simpson JS, Ventura S. "Saw palmetto - LiverTox - NCBI Bookshelf." NCBI. ↩ ↩² ↩³ ↩⁴

2. Elliot Fagelman. "Saw Palmetto Berry as a Treatment for BPH." NCBI. ↩ ↩²

3. Evyatar Evron. "Natural Hair Supplement: Friend or Foe? Saw Palmetto, a Systematic Review in Alopecia." NCBI. ↩ ↩²

4. Andrew L. Avins. "Safety and Toxicity of Saw palmetto in the Complementary and Alternative Medicine for Urological Symptoms (CAMUS) Trial." NCBI. ↩

5. Shizuo Yamada. "Beneficial Effects of Saw Palmetto Fruit Extract on Urinary Symptoms in Japanese Female Subjects by a Multicenter, Randomized, Double-Blind, Placebo-Controlled Study." NCBI. ↩ ↩²