Saw Palmetto
Serenoa repens
Also known as: Serenoa repens, Sabal serrulata, American dwarf palm, Cabbage palm, Saw palmetto berry
Evidence Strength: MODERATE
This ingredient is classified as unclassified risk (GIRI score: 3.0/10). The score reflects 1 active safety or regulatory signal recorded in the monitoring database.
Safety Profile
Common Adverse Effects
- Nausea
- headache
- dizziness
- constipation
- diarrhea
Serious Adverse Effects
- Liver damage
- pancreatitis
- bleeding disorders
Contraindications
- Liver disease
- bleeding disorders
- hormone-sensitive cancers
- People taking Warfarin
Interactions
| Drug / Nutrient | Interaction Mechanism | Warning |
|---|---|---|
| Warfarin | increased bleeding risk — monitor INR closely. Finasteride: additive effects — use with caution. Oral contraceptives: potential hormonal interference — consult healthcare provider. | Monitor |
Evidence and Scientific Findings
Ingredient Overview
Biological and Chemical Classification
- Chemical Class
- Fatty acids and sterols
- Biological Class
- Phytosterol
- Natural Source
- Serenoa repens berries
- Scientific Name
- Serenoa repens
- Chemical Formula
- C30H50O
- CAS Number
- 84604-15-9
Mechanism of Action
Clinical Evidence of Effectiveness
| Indication | Evidence Level | Summary |
|---|---|---|
| General | Moderate | Clinical studies on Saw Palmetto have shown mixed results. Some trials suggest modest improvements in urinary symptoms associated with BPH, while others show no significant benefit compared to placebo. The variability in outcomes may be due to differences in study design, dosage, and extract standardization. Overall, the evidence is considered moderate, with some support for its use in mild to moderate BPH. |
Pharmacokinetics
Recommended Dosage
| Condition / Use | Typical Dose |
|---|---|
| BPH | 160 mg twice daily. Hair loss: 200-320 mg daily. General prostate health: 160-320 mg daily. |
Dosage ranges are based on clinical studies and commonly used supplement formulations. Individual requirements may vary.
SETI — Scientific Evidence Transparency Index
Executive Summary — Ingredient Assessment
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or RCT)
- Main clinical benefit observed: Saw Palmetto, derived from the berries of the Serenoa repens plant, is commonly used in dietary supplements for…
- Evidence consistency: High consistency across studies (100%)
- Saw Palmetto is generally considered safe for most adults when used at recommended doses. However, it may pose risks for individuals with liver disease or bleeding disorders due to its potential to affect liver enzymes and platelet function. Pregnant or breastfeeding women should avoid use due to insufficient safety data. Regulatory agencies have not issued significant warnings, but caution is advised in patients with hormone-sensitive conditions.
- USA/FDA — Approved
The available scientific evidence for Saw Palmetto indicates notable safety signals that warrant caution. Use should be considered carefully and monitored, particularly in sensitive populations or alongside other medications.
Total SETI Score
High risk| Evidence quality | 10/40 |
| Evidence consistency | 20/20 |
| Safety signals | 0/20 |
| Study recency | 10/10 |
| Evidence transparency | 9/10 |
Evidence Summary
- 10 studies reviewed
- 0 high-quality studies (meta-analysis or systematic review)
- 0 studies identified benefits or no safety concern (GREEN)
- 10 studies reported limited or advisory safety evidence (YELLOW)
Evidence Policy
Only peer-reviewed scientific literature indexed in PubMed or comparable databases is included in this evaluation. Commercial websites, blogs, and marketing materials are excluded. All references include direct traceable links to source documents.
Last updated: 01 მაი 2026, 05:14
Evidence Distribution
-
Observational / other LOW evidence YELLOWPharmacology, efficacy and safety of different extracts of Serenoa repens in patients with lower urinary tract symptoms and benign prostatic hyperplasia: a… ↗DE Nunzio C et al.. Pharmacology, efficacy and safety of different extracts of Serenoa repens in patients with lower urinary tract symptoms and benign prostatic hyperplasia: a narrative review.. Minerva Urol Nephrol. 2026. PMID:42023747.PMID 42023747 ↗Journal Minerva Urol NephrolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/42023747/
-
Observational / other LOW evidence YELLOWA Multi-Target Phytotherapeutic Approach to Benign Prostatic Hyperplasia: Preclinical Characterization of a PhytoBPH-Mix. ↗Amante C et al.. A Multi-Target Phytotherapeutic Approach to Benign Prostatic Hyperplasia: Preclinical Characterization of a PhytoBPH-Mix.. Nutrients. 2026. PMID:41754167.PMID 41754167 ↗Journal NutrientsYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41754167/
-
Observational / other LOW evidence YELLOWInvestigating the Neuroprotective Effects of Saw Palmetto Fruit Extract Against D-Galactose and Aluminum Chloride Induced Alzheimer's Disease: In Vivo Study. ↗Nisar A et al.. Investigating the Neuroprotective Effects of Saw Palmetto Fruit Extract Against D-Galactose and Aluminum Chloride Induced Alzheimer's Disease: In Vivo Study.. Neurochem Res. 2026. PMID:41701395.PMID 41701395 ↗Journal Neurochem ResYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41701395/
-
Observational / other LOW evidence YELLOWCorrection to "[Efficacy of Serenoa repens Extract Combined With Alfuzosin Versus Alfuzosin Alone in Men With Lower Urinary Tract Symptoms Due to… ↗Correction to "[Efficacy of Serenoa repens Extract Combined With Alfuzosin Versus Alfuzosin Alone in Men With Lower Urinary Tract Symptoms Due to Benign Prostatic Hyperplasia: A Multicenter Randomized Study (The Prostate, 2025). https://doi.org/10.1002/pros.70071]".. Prostate. 2026. PMID:41664556.PMID 41664556 ↗Journal ProstateYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41664556/
-
Observational / other LOW evidence YELLOWThe Safety and Efficacy of a Novel Saw Palmetto (Serenoa repens) Extract for Promoting Hair Growth in Adults With Self-Perceived Thinning Hair:… ↗Ablon G. The Safety and Efficacy of a Novel Saw Palmetto (Serenoa repens) Extract for Promoting Hair Growth in Adults With Self-Perceived Thinning Hair: 180-Day Results.. J Cosmet Dermatol. 2026. PMID:41652806.PMID 41652806 ↗Journal J Cosmet DermatolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41652806/
-
Observational / other LOW evidence YELLOWNovel therapeutic potential of Serenoa repens in rat PCOS: Insights from network pharmacology and in vivo studies. ↗Taha AM et al.. Novel therapeutic potential of Serenoa repens in rat PCOS: Insights from network pharmacology and in vivo studies.. J Ethnopharmacol. 2026. PMID:41628869.PMID 41628869 ↗Journal J EthnopharmacolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41628869/
-
Observational / other LOW evidence YELLOWCan we identify a post-Serenoa syndrome (PSS)? A case series on sexual and psychiatric side effects of Serenoa repens. ↗Firenzuoli F et al.. Can we identify a post-Serenoa syndrome (PSS)? A case series on sexual and psychiatric side effects of Serenoa repens.. Br J Clin Pharmacol. 2026. PMID:41507085.PMID 41507085 ↗Journal Br J Clin PharmacolYear 2026Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41507085/
-
Observational / other LOW evidence YELLOWBotanical drug preparations for alleviating hair loss in menopausal women: a global ethnopharmacological mini-review. ↗Huang Z et al.. Botanical drug preparations for alleviating hair loss in menopausal women: a global ethnopharmacological mini-review.. Front Pharmacol. 2025. PMID:41383467.PMID 41383467 ↗Journal Front PharmacolYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41383467/
-
Observational / other LOW evidence YELLOWThe Safety and Efficacy of a Proprietary Bioactive Fatty Acids Extract From Saw Palmetto (Serenoa repens) for Promoting Hair Growth and Reducing… ↗Ablon G. The Safety and Efficacy of a Proprietary Bioactive Fatty Acids Extract From Saw Palmetto (Serenoa repens) for Promoting Hair Growth and Reducing Hair Loss in Adults With Self-Perceived Thinning Hair: 90-Day Results.. J Cosmet Dermatol. 2025. PMID:41319217.PMID 41319217 ↗Journal J Cosmet DermatolYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41319217/
-
Observational / other LOW evidence YELLOWNon-interventional and medical management of lower urinary tract symptoms related to benign prostatic hyperplasia in men: Guidelines of the French LUTS Committee… ↗Anract J et al.. Non-interventional and medical management of lower urinary tract symptoms related to benign prostatic hyperplasia in men: Guidelines of the French LUTS Committee (CTMH).. Fr J Urol. 2025. PMID:41271371.PMID 41271371 ↗Journal Fr J UrolYear 2025Study type Observational / otherEvidence strength LOW evidencePubMed link https://pubmed.ncbi.nlm.nih.gov/41271371/
Score Transparency
0 of 10 approved references (score saturates at 10). More peer-reviewed studies = stronger evidence base.
Method: Q = number of approved references ÷ 10 (capped at 1.0)
Limited — mostly case reports or animal studies
Method: L = mean study-level weight across approved references. Level 1 (meta-analysis / systematic review) = 1.0; Level 2 (RCT) = 0.8; Level 3 (cohort/case-control) = 0.6; Level 4 (case report) = 0.4; Level 5 (animal / in-vitro) = 0.2.
Mixed or neutral — roughly equal benefit and risk signals
Method: D = (sum of risk-scored references − sum of benefit-scored references) ÷ total evidence score, then scaled from [−1, 1] to [0, 1]. 0.0 = pure benefit; 0.5 = neutral; 1.0 = pure risk.
One or more monitoring-level safety signals active
Method: S = 0.5 (neutral baseline) + sum of active signal severity deltas ÷ 10. Severity deltas: Critical = +2.0, High = +1.5, Moderate = +1.0, Low = +0.5. Capped at 1.0.
Final GIRI Score for Saw Palmetto. Risk level thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
Full methodology & data sources
The GIRI Score is computed entirely from structured data — no editorial scoring or subjective weighting is applied at any step.
- References: Only approved references are counted. Each reference is assigned an evidence level (L1–L5) and a direction (risk / neutral / benefit) by the reference manager or AI classifier.
- Safety Signals: Sourced from regulatory agencies (FDA, EMA, Health Canada, TGA, and others) and pharmacovigilance databases. Only active signals count toward the score.
- Formula version: GIRI Score v3.7.0 — Q × L × D × S × 10.
- Limitations: The score reflects published evidence and recorded signals as of the last update date. It is not a clinical risk assessment and should not replace advice from a qualified healthcare professional.
Risk Level Classification
Based on available regulatory signals and scientific evidence, this ingredient presents a low safety concern under normal conditions of use.
0–3.0
3.0–5.5
5.5–7.5
7.5–10
The score pin shows exactly where this ingredient falls on the fixed risk scale.
What drove the Low classification for Saw Palmetto
A score of 3.0 places this ingredient in the Low band. Thresholds: Low 0–3.0 · Moderate 3.0–5.5 · High 5.5–7.5 · Critical 7.5–10.
0 approved references.
Limited — mostly case reports or animal studies (Level 4–5).
Neutral or mixed — benefit and risk signals roughly balanced.
1 active signal (highest severity: Moderate). Each active signal raises S above the neutral baseline of 0.5.
1 jurisdiction has active restrictions or advisories. Regulatory signals are recorded as Safety Signals and raise the S component.
How are the Low / Moderate / High / Critical thresholds defined?
The four risk levels are fixed score bands. A score is assigned to exactly one level based on where it falls:
| Level | Score | Meaning |
|---|---|---|
| LOW | 0.0 – 2.9 | Sparse or predominantly beneficial evidence. No active safety alerts. |
| MODERATE | 3.0 – 5.4 | Mixed signals — some risk alongside benefit. Caution at high doses or in sensitive groups. |
| HIGH | 5.5 – 7.4 | Multiple studies or regulatory alerts documenting adverse effects. Professional oversight recommended. |
| CRITICAL | 7.5 – 10 | Regulatory restrictions in one or more major jurisdictions. Serious documented harm. Avoid without specialist supervision. |
Thresholds are fixed constants (GIRI_Score_Utils::LEVEL_THRESHOLDS). They do not change per ingredient and are never subject to editorial adjustment.