II. Indications (Purported benefits)

III. Efficacy

  1. Initial studies suggested benefit for urologic symptoms in BPH
    1. Saw Palmetto equaled Finasteride for improved urine flow (but not Prostate volume)
    2. Appeared effective for mild to moderate urinary obstructive symptoms
    3. Wilt (1998) JAMA 280:1604 [PubMed]
    4. Carraro (1996) Prostate 29:231 [PubMed]
  2. However, later studies found no benefit for urologic symptoms in BPH
    1. Placebo-controlled study found no benefit
      1. Bent (2006) N Engl J Med 354: 557-66 [PubMed]
    2. Large metaanalysis found no benefit
      1. Did not reduce Nocturia, Peak Urine Flow, Prostate size or AUA Symptom Index for BPH
      2. Tacklind (2012) Cochrane Database Syst Rev (12): CD001423 [PubMed]
    3. Cochrane Review also found no benefit for urologic symptoms in BPH
      1. Franco (2023) Cochrane Database Syst Rev 6(6):CD001423 +PMID: 37345871 [PubMed]

IV. Dosing (extracts are not standardized)

  1. Saw Palmetto 160 mg PO bid or 320 mg PO qd

V. Background

  1. Saw Palmetto
    1. Scientific names: Serenoa repens, Sabal serrulata
    2. Dwarf palm tree grows in southeast U.S.
  2. Active ingredient: Sitosterols
  3. Extract compositions are not standardized
    1. Some preparations contain almost no active ingredient
    2. Feifer (2002) J Urol 168:150-4 [PubMed]

VI. Pharmacokinetics: Saw Palmetto berry

  1. In vitro activity
    1. Anti-androgen
    2. Anti-Estrogen
    3. Anti-Inflammatory
    4. Inhibits Testosterone-5a-reductase (High dose)
      1. Less Testosterone to Dihydrotestosterone conversion
    5. Inhibits binding of androgen to receptor (High dose)
  2. In vivo activity
    1. No anti-androgen effects demonstrable in rats
    2. No decreased dihydrotestosterone in men after 7 days
  3. References
    1. Rhodes (1993) Prostate 22:43 [PubMed]

VII. Adverse Effects (Incidence <3%)

  1. Headache
  2. Gastrointestinal upset
  3. Hypertension
  4. Impotence
  5. Decreased libido

VIII. Drug Interactions

  1. No significant Drug Interactions

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