Saw palmetto is a plant extract widely used for BPH (benign prostatic hyperplasia) and hair loss. Saw palmetto benefits have mixed evidence — some studies show modest effects, large rigorous trials disappointing.
For BPH
Mixed evidence:
- Some smaller studies show modest symptom improvement
- Large STEP trial (320 mg saw palmetto vs placebo) negative
- Cochrane reviews suggest little to no benefit
- Possible benefit for milder symptoms in some patients
Prescription medications (alpha-blockers, finasteride) more reliable for moderate-severe BPH.
For hair loss
Some evidence:
- 5-alpha reductase inhibition (similar mechanism to finasteride)
- Effect weaker than finasteride
- Some studies show modest improvement
- Common in topical hair loss products
Dosing
- BPH: 320 mg daily of standardized extract
- Hair loss: similar oral doses or topical preparations
Safety
- Generally well-tolerated
- Mild GI side effects possible
- Theoretical bleeding interactions
Frequently Asked Questions
Does saw palmetto really work for BPH?
Mixed evidence. Some patients benefit; rigorous trials show limited effect.
Is saw palmetto as effective as finasteride for hair loss?
Generally weaker. Finasteride has stronger evidence.
How long until saw palmetto works?
3-6 months for symptom improvement if it’s going to help.
Can I take saw palmetto with finasteride?
Both target similar pathway. Discuss with provider.
Are there side effects?
Generally well-tolerated. Some patients experience GI upset.
The bottom line on saw palmetto
Mixed evidence for BPH and hair loss. Effects modest if real. Prescription alternatives more reliable for significant symptoms.