Supplement
Beta-sitosterol
Beta-sitosterol is the main plant sterol in the extracts taken as capsules for an enlarged prostate. In short placebo-controlled trials from the 1990s, men taking it had faster urine flow, less urine left behind and lower symptom scores, although the prostate itself did not get smaller. How well it works over years and how safe it is long term have not been studied. People with sitosterolaemia, a rare inherited condition in which plant sterols build up in the body, should not take it.
Sources: PMID 7540705; PMID 9313662; PMID 25941971
- Updated
- How we grade
- Best evidence
- Grade B: moderate evidence
What beta-sitosterol is good for
How we grade →Moderate evidence
Peak Urine Flow: Improves
All 4 outcomes ↓
Is beta-sitosterol safe?
Safety note. Talk to a doctor or pharmacist before you start beta-sitosterol if you take prescription medicines, are pregnant or breastfeeding, or have a long-term health condition. Supplements can interact with medicines.
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
BUrination Problems
▲ Peak Urine Flow · ▲ Post-void Residual Urine · ▲ Urinary Symptoms4 outcomes · 2 studies
Urination Problems: all the evidence on its own page
| Grade | Outcome | Effect | Size and studies |
|---|---|---|---|
| B | Peak Urine FlowImprovementStudied as: Men with urinary symptoms from an enlarged prostate (benign prostatic hyperplasia, BPH) took beta-sitosterol (plant-sterol extracts with beta-sitosterol as the main sterol; preparations were not standardised) as capsules by mouth daily for 6 months, against placebo, in two trials from the 1990s. No certainty rating exists for these outcomes.Studies that measured peak urine flow (2 studies)
| Improves | 2 studiesReviewed |
| B | Post-void Residual UrineImprovementStudied as: Men with urinary symptoms from an enlarged prostate (benign prostatic hyperplasia, BPH) took beta-sitosterol (plant-sterol extracts with beta-sitosterol as the main sterol; preparations were not standardised) as capsules by mouth daily for 6 months, against placebo, in two trials from the 1990s. No certainty rating exists for these outcomes.Studies that measured post-void residual urine (2 studies)
| Improves | 2 studiesReviewed |
| B | Urinary SymptomsImprovementStudied as: Men with urinary symptoms from an enlarged prostate (benign prostatic hyperplasia, BPH) took beta-sitosterol (plant-sterol extracts with beta-sitosterol as the main sterol; preparations were not standardised) as capsules by mouth daily for 6 months, against placebo, in two trials from the 1990s. No certainty rating exists for these outcomes.Studies that measured urinary symptoms (2 studies)
| Improves | 2 studiesReviewed |
| C | Prostate SizeNo effectStudied as: Men with urinary symptoms from an enlarged prostate (benign prostatic hyperplasia, BPH) took beta-sitosterol (plant-sterol extracts with beta-sitosterol as the main sterol; preparations were not standardised) as capsules by mouth daily for 6 months, against placebo, in two trials from the 1990s. No certainty rating exists for these outcomes.Studies that measured prostate size (1 study) | 1 studyReviewed |