II. Indications (Purported benefits)
III. Efficacy
- Initial studies suggested benefit
- Saw Palmetto equaled Finasteride for improved urine flow (but not Prostate volume)
- Appeared effective for mild to moderate urinary obstructive symptoms
- Wilt (1998) JAMA 280:1604 [PubMed]
- Carraro (1996) Prostate 29:231 [PubMed]
- However, later studies found no benefit
- Placebo-controlled study found no benefit
- Large metaanalysis found no benefit
IV. Dosing (extracts are not standardized)
- Saw Palmetto 160 mg PO bid or 320 mg PO qd
V. Background
- Saw Palmetto
- Scientific names: Serenoa repens, Sabal serrulata
- Dwarf palm tree grows in southeast U.S.
- Active ingredient: Sitosterols
- Extract compositions are not standardized
- Some preparations contain almost no active ingredient
- Feifer (2002) J Urol 168:150-4 [PubMed]
VI. Pharmacokinetics: Saw Palmetto berry
- In vitro activity
- Anti-androgen
- Anti-Estrogen
- Anti-Inflammatory
- Inhibits Testosterone-5a-reductase (High dose)
- Less Testosterone to Dihydrotestosterone conversion
- Inhibits binding of androgen to receptor (High dose)
- In vivo activity
- No anti-androgen effects demonstrable in rats
- No decreased dihydrotestosterone in men after 7 days
- References
VII. Adverse Effects (Incidence <3%)
- Headache
- Gastrointestinal upset
- Hypertension
- Impotence
- Decreased libido
VIII. Drug Interactions
- No significant Drug Interactions