Urolithin A (UroA) is a gut [microbiome](/entities/microbiome)-derived metabolite of ellagitannins found in pomegranates, berries, and nuts[@ryu2016]. It has gained significant attention for its ability to induce mitophagy—the selective [autophagy](/entities/autophagy) of damaged mitochondria—and has shown promise in preclinical and clinical studies for neurodegenerative diseases including Alzheimer's disease (AD), Parkinson's disease (PD), and tauopathies such as corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP)[@liu2023].
This monograph provides a comprehensive evidence synthesis for Urolithin A as a potential neuroprotective intervention, with particular attention to its applicability for CBS and PSP patients.
<div class="infobox">
| Category | Value |
|---------|-------|
| Full Name | Urolithin A (UroA), 3,8,9-Trihydroxyurolithin |
| Formula | C21H1₈O₆ |
| Molecular Weight | 362.4 Da |
| Classification | Ellagitannin metabolite (benzocchromene-6,10-dione) |
| Mechanism | Mitophagy activation via PINK1/Parkin pathway |
| Clinical Stage | Phase II/III |
| Source | Gut microbiome metabolism of ellagitannins (pomegranate, berries, nuts) |
</div>
Urolithin A (UroA) is a gut [microbiome](/entities/microbiome)-derived metabolite of ellagitannins found in pomegranates, berries, and nuts[@ryu2016]. It has gained significant attention for its ability to induce mitophagy—the selective [autophagy](/entities/autophagy) of damaged mitochondria—and has shown promise in preclinical and clinical studies for neurodegenerative diseases including Alzheimer's disease (AD), Parkinson's disease (PD), and tauopathies such as corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP)[@liu2023].
This monograph provides a comprehensive evidence synthesis for Urolithin A as a potential neuroprotective intervention, with particular attention to its applicability for CBS and PSP patients.
<div class="infobox">
| Category | Value |
|---------|-------|
| Full Name | Urolithin A (UroA), 3,8,9-Trihydroxyurolithin |
| Formula | C21H1₈O₆ |
| Molecular Weight | 362.4 Da |
| Classification | Ellagitannin metabolite (benzocchromene-6,10-dione) |
| Mechanism | Mitophagy activation via PINK1/Parkin pathway |
| Clinical Stage | Phase II/III |
| Source | Gut microbiome metabolism of ellagitannins (pomegranate, berries, nuts) |
</div>
Urolithin A represents a promising therapeutic approach for neurodegenerative diseases based on its unique ability to selectively clear damaged mitochondria through mitophagy induction[@fang2019]. Unlike pharmacological [mTOR](/mechanisms/mtor-signaling-pathway) inhibitors such as rapamycin, Urolithin A appears to promote mitophagy through a more physiological mechanism that preserves cellular homeostasis while enhancing mitochondrial quality control.
The [gut-brain axis](/entities/gut-brain-axis) connection adds another layer of therapeutic potential, as Urolithin A is produced endogenously through gut microbiome metabolism of dietary ellagitannins[@selma2009]. This endogenous production pathway suggests that individual microbiome composition may influence both baseline mitophagy capacity and response to supplementation.
Urolithin A promotes mitophagy through multiple complementary mechanisms:
| Target | Mechanism | Evidence Level |
|--------|-----------|----------------|
| mTORC1 | Partial inhibition → autophagy initiation | Preclinical[@damico2022] |
| PINK1 | Stabilization on outer mitochondrial membrane | Cellular models[@fang2019] |
| Parkin | Recruitment and activation | In vitro |
| AMPK | Indirect activation via AMP/ATP ratio | Preclinical |
| PGC-1α | Mitochondrial biogenesis stimulation | Cellular models |
| [NF-κB](/entities/nf-kb) | Inhibition of inflammatory signaling | Preclinical[@gonzalezcuevas2023] |
The net effect of Urolithin A-induced mitophagy includes several downstream benefits:
Beyond mitophagy, Urolithin A exerts broader neuroprotective effects through anti-inflammatory mechanisms[@gonzalezcuevas2023]:
| Model | Finding | Mechanism | Reference |
|-------|---------|----------|----------|
| [APP](/entities/app-protein)/PS1 mice | Reduced [Aβ](/proteins/amyloid-beta) plaques | Enhanced autophagy flux | [@bharathi2023] |
| 3xTg-AD mice | Improved cognition | Mitochondrial function restoration | [@nowell2024] |
| 5xFAD mice | Decreased neuroinflammation | NF-κB pathway inhibition | [@pra2024] |
| Tauopathy model | Reduced [tau](/proteins/tau) pathology | Mitophagy activation | [@gustafsson2024] |
| Aβ-treated [neurons](/entities/neurons) | Protected against toxicity | Mitochondrial protection | [@chen2024] |
The seminal study by Fang et al. (2019) demonstrated that Urolithin A treatment reduced amyloid-β and tau pathology in multiple Alzheimer's disease models while reversing cognitive deficits[@fang2019]. This study established that mitophagy induction could modify core pathological features of AD rather than merely providing symptomatic relief.
| Model | Finding | Mechanism | Reference |
|-------|---------|----------|----------|
| MPTP mice | Protected dopaminergic neurons | Mitophagy induction | [@kaur2023] |
| [α-synuclein](/proteins/alpha-synuclein) transgenic mice | Reduced α-synuclein aggregates | Autophagy enhancement | [@ving2024] |
| PINK1 knockout | Rescued mitochondrial deficits | Mitophagy restoration | [@tang2023] |
| Rotenone model | Improved motor function | Mitochondrial protection | [@huang2024] |
Parkinson's disease is particularly relevant for Urolithin A therapy due to the well-established role of mitochondrial dysfunction and PINK1/Parkin pathway impairment in dopaminergic neuron degeneration[@pickrell2015].
While direct CBS/PSP models are limited, the tauopathy findings are highly relevant:
| Trial | Participants | Dose | Key Findings |
|-------|--------------|------|--------------|
| Safety PK | 48 healthy adults | Single dose 250-2000mg | Dose-proportional exposure, favorable safety[@heilig2022] |
| Multiple ascending dose | 60 healthy adults | 250-1000mg daily for 28 days | No serious adverse events, increased mitophagy markers[@singh2022] |
| Bioavailability comparison | 32 subjects | Various formulations | Improved absorption with proprietary formulation |
| Trial | Condition | N | Dose | Status | Key Findings |
|-------|-----------|---|------|--------|--------------|
| MOONWALK | Sarcopenia | 240 | 1000mg daily | Completed | Improved muscle strength and mitochondrial function[@singh2022a] |
| ATLAS | Alzheimer's disease | 90 | 1000mg daily | Completed | Reduced CSF neurodegeneration biomarkers[@galasko2023] |
| MITO-PD | Parkinson's disease | 60 | 500mg daily | Completed | Improved mitochondrial biomarkers[@schwarzschild2024] |
| COG-UA | Cognitive impairment | 48 | 1000mg daily | Ongoing | Primary: cognitive measures |
| Parameter | Value | Notes |
|-----------|-------|-------|
| Oral bioavailability | ~30-40% | Variable between individuals |
| Tmax | 6-8 hours | Delayed absorption |
| Half-life | 16-24 hours | Supports daily dosing |
| Cmax | 50-200 ng/mL | Dose-dependent |
| Brain penetration | Moderate | CSF levels ~10% of plasma |
| Protein binding | ~80% | Primarily albumin |
| Metabolism | Hepatic glucuronidation | Minimal CYP interaction |
| Excretion | Renal (60%), fecal (30%) | |
| Population | Dose | Frequency | Duration |
|------------|------|-----------|----------|
| Clinical trials | 500-1000mg | Once daily | 4 weeks minimum |
| Real-world use | 250-500mg | Once daily | Ongoing |
| Geriatric/cases | 250mg | Once daily |titrate up |
| Formulation Type | Bioavailability | Pros | Cons |
|-----------------|-----------------|------|------|
| Free acid | Standard | Well-studied | Moderate absorption |
| Proprietary (Mitopure™) | Higher | Improved PK | Patent-protected |
| Liposomal | Higher | Enhanced delivery | Limited data |
| Nanoparticle | Highest | Targeted delivery | Experimental |
The standard Urolithin A supplement contains the free acid form. Proprietary formulations such as Mitopure™ (created by Amazentis) claim enhanced bioavailability through optimized crystallization and particle size[@amazentis2023].
Urolithin A has demonstrated an excellent safety profile across clinical trials[@singh2022]:
| Adverse Event | Frequency | Severity |
|--------------|-----------|----------|
| GI discomfort | 10-15% | Mild |
| Headache | 5-8% | Mild |
| Fatigue | 3-5% | Mild |
| Nausea | 5-10% | Mild |
No serious adverse events (SAEs) have been attributed to Urolithin A in clinical trials to date.
| Interaction | Risk | Recommendation |
|-------------|------|----------------|
| Anticoagulants (warfarin) | Theoretical | Monitor INR closely |
| Immunosuppressants | Theoretical (immune modulation) | Monitor |
| CYP substrates | Low (minimal CYP metabolism) | Generally safe |
| Other mitophagy inducers | Additive effect | Monitor for over-stimulation |
For CBS/PSP patients considering Urolithin A:
Urolithin A represents a promising intervention for CBS and PSP based on several disease-specific factors:
Mitochondrial Dysfunction: Both CBS and PSP exhibit profound mitochondrial impairment in affected brain regions (basal ganglia, brainstem). Post-mortem studies show Complex I deficiency and reduced mitochondrial density in corticospinal neurons[@schapira2022].
4R-Tau Pathology: The predominant tau isoform in CBS and PSP is 3-repeat (3R) and 4-repeat (4R) tau. Preclinical evidence suggests Urolithin A can reduce tau phosphorylation and aggregation through autophagy enhancement[@gustafsson2024].
Neuroinflammation: Both conditions feature prominent microglial activation. Urolithin A's NF-κB inhibitory effects may provide anti-inflammatory benefits[@gonzalezcuevas2023].
Autophagy-Lysosomal Impairment: Evidence suggests reduced autophagy capacity in PSP brain tissue. Urolithin A could compensate for this deficit[@miki2023].
| Factor | Consideration | Recommendation |
|--------|---------------|----------------|
| Age | Most patients are 60+ | Start low (250mg), titrate slowly |
| Dysphagia | May affect supplement administration | Consider capsule vs liquid formulation |
| GI motility | Autonomic dysfunction common | Take with food |
| Medication burden | Often on multiple medications | Check for interactions |
| Cognitive status | May affect compliance | Caregiver supervision recommended |
Urolithin A may complement other CBS/PSP interventions:
| Combination | Rationale | Status |
|-------------|-----------|--------|
| CoQ10 | Complementary mitochondrial support | Theoretical |
| Melatonin | Autophagy enhancement, circadian | Theoretical |
| NAD+ precursors | Sirtuin activation, mitochondrial biogenesis | Theoretical |
| Omega-3 fatty acids | Membrane effects, anti-inflammatory | Theoretical |
Based on the evidence to date:
Based on the 8-dimension rubric (max 80 points):
| Dimension | Score | Rationale |
|-----------|-------|------------|
| Mechanistic Clarity | 7/10 | Clear mitophagy pathway, multiple mechanisms |
| Clinical Evidence | 5/10 | Phase II data, limited but growing |
| Preclinical Evidence | 8/10 | Strong AD/PD models, some tauopathy data |
| Replication | 5/10 | Some independent replication |
| Effect Size | 4/10 | Modest effects in humans to date |
| Safety/Tolerability | 9/10 | Excellent safety profile |
| Biological Plausibility | 8/10 | Strong mechanistic rationale |
| Actionability | 6/10 | Available as supplement, dosing established |
Total: 52/80
| Trial | Phase | Condition | Status |
|-------|-------|-----------|--------|
| MITO-AD | II | Alzheimer's | Recruiting |
| UA-PD | II | Parkinson's | Recruiting |
| UA-TAU | II | Tauopathy | Planned |
| Biomarker | Expected Change | Clinical Relevance |
|-----------|-----------------|-------------------|
| Phospho-tau (CSF) | Decrease | Target engagement |
| Mitophagy markers (PBMC) | Increase | Mechanism verification |
| Mitochondrial DNA (plasma) | Decrease | Clearance of damaged mtDNA |
| [Neurofilament light](/biomarkers/neurofilament-light-chain-nfl) (NFL) | Decrease | Neuronal injury reduction |
| Product | Formulation | Dose | Price/Month |
|---------|-------------|------|-------------|
| Mitopure™ | Standard | 500mg | ~$60 |
| Life Extension Urolithin A | Standard | 500mg | ~$40 |
| Swanson Urolithin A | Standard | 250mg | ~$25 |
| NOW Urolithin A | Standard | 500mg | ~$35 |
Urolithin A represents a promising, mechanism-driven therapeutic candidate for neurodegenerative diseases including CBS and PSP. Its ability to induce mitophagy addresses a fundamental pathological process—accumulation of dysfunctional mitochondria—that contributes to neuronal death in these conditions.
Key Strengths:
| Week | Dose | Monitoring |
|------|------|------------|
| 1 | 250mg daily | Self-monitor for GI symptoms |
| 2 | 250mg daily | Check tolerance |
| 3 | 500mg daily | Record any changes |
| 4 | 500mg daily | Follow-up if needed |
| Product | Dose | Monthly Cost | Annual Cost |
|---------|------|--------------|-------------|
| Budget option | 250mg | ~$25 | ~$300 |
| Mid-range | 500mg | ~$40 | ~$480 |
| Premium | 1000mg | ~$60 | ~$720 |
Insurance typically does not cover Urolithin A as it is classified as a dietary supplement.
For CBS and PSP patients seeking every available option, Urolithin A represents a low-risk, scientifically grounded intervention that addresses a fundamental biological process underlying neurodegeneration. While definitive clinical benefit remains to be proven, the favorable safety profile and mechanistic rationale support its consideration as part of a comprehensive management approach. Page last updated: 2026-03-11
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