Urolithin A: What the Clinical Research Shows

Co-authored by Danielle Orozco Cosio, PhD; Customer Success and GTM Lead, MyDose AI

Mitochondrial dysfunction is one of the hallmarks of aging. Cells' power plants gradually lose efficiency, energy production declines, and recovery from exercise becomes slower. Unlike some longevity interventions that target single pathways, urolithin A stands out because it has clinical evidence, published in respected journals, showing measurable improvements in mitochondrial biomarkers, muscle strength, endurance, and exercise-related outcomes. This guide walks through what the research actually shows, where the evidence is strongest, and what remains unknown.

What Is Urolithin A, and Why Does It Matter?

Urolithin A is a compound created by your gut microbiome when you consume ellagic acid, found naturally in pomegranates, berries, and nuts. Your gut bacteria metabolize these plant polyphenols into urolithin A, but there is substantial variability in how efficiently people make this conversion. Only about 40% of people are efficient "urolithin converters," meaning their microbiome produces meaningful amounts of urolithin A from dietary precursors.

This is why urolithin A supplementation exists. Instead of relying on microbiome conversion, you can take pre-formed urolithin A directly and bypass that step entirely.

The reason urolithin A gets attention in longevity science is its effect on mitochondrial health. It activates mitophagy, a process in which cells selectively break down and recycle damaged mitochondria. This is particularly relevant to aging because dysfunctional mitochondria can accumulate over time, contributing to declining cellular energy production and metabolic dysfunction.

The PINK1/Parkin pathway is one of the best-characterized mechanisms involved in mitophagy. When mitochondria are damaged, PINK1 accumulates on the mitochondrial surface and recruits Parkin, helping mark damaged mitochondria for removal. Preclinical research has linked urolithin A to mitophagy signaling, while human trials have shown changes in mitochondrial gene expression and metabolic biomarkers consistent with improved mitochondrial health. (Ryu et al., Nature Medicine 2016; Andreux et al., Nature Metabolism 2019)

The Andreux 2019 Study: The First Human Trial

The first human evidence for urolithin A comes from a randomized, placebo-controlled first-in-human trial by Andreux et al., published in Nature Metabolism in 2019. The study enrolled healthy, sedentary older adults ages 61 to 85.

Participants received urolithin A at several doses, including 500mg and 1000mg, or placebo. The multiple-dose portion ran for four weeks. Safety was the primary outcome, and researchers also measured biomarkers of mitochondrial function.

The results: urolithin A was well tolerated, and 500mg and 1000mg daily modulated molecular signatures associated with mitochondrial health, including skeletal-muscle mitochondrial gene expression and plasma acylcarnitine profiles. These were biomarker changes rather than direct strength measurements, but they established that oral urolithin A can influence mitochondrial biology in humans.

The 500mg dose used in this study is dose-matched to TimeWarp's Energize Pill. That is part of why this trial is particularly relevant to the formulation.

Muscle Strength and Performance: The Singh 2022 Data

A later randomized controlled trial by Singh et al., published in Cell Reports Medicine in 2022, tested the effects of urolithin A supplementation on muscle strength, exercise performance, and mitochondrial biomarkers. The four-month study enrolled 88 untrained adults ages 40 to 64 and tested 500mg and 1000mg daily.

The study reported approximately 12% improvement in muscle strength compared with placebo, along with improvements in exercise-performance measures and biomarkers of mitochondrial health. A separate four-month randomized trial in 66 adults ages 65 to 90, Liu et al. in JAMA Network Open, found significant improvements in hand and leg muscle endurance at 1000mg daily, although its primary outcomes of six-minute walk distance and maximal ATP production did not significantly differ from placebo.

Taken together, the trials show measurable effects at both 500mg and 1000mg, but they do not establish a single optimal dose for every outcome. Longer studies have also been more likely to capture functional changes than the initial four-week safety and biomarker trial.

Beyond Muscle: The 2025 Immune Findings

In 2025, a study published in Nature Aging by Denk et al. expanded the urolithin A story beyond muscle and mitochondria. This randomized, double-blind, placebo-controlled trial tested 1000mg of urolithin A daily in 50 healthy adults ages 45 to 70 over four weeks and measured immune markers.

Urolithin A supplementation expanded peripheral naive-like CD8+ T cells and increased their fatty acid oxidation capacity. The treated group also showed fewer terminally exhausted T cells.

This is significant because it suggests that urolithin A's effects on mitochondrial biology may extend beyond skeletal muscle to immune-cell function. The dose here was 1000mg, higher than the 500mg in TimeWarp's Energize Pill, and the trial was small and short, so these findings are promising but still early and require replication.

How Urolithin A Differs From Other Mitochondrial Supports

TimeWarp includes three ingredients that target mitochondrial health through different mechanisms: Urolithin A (500mg), NMN (350mg), and Ca-AKG (1000mg).

Urolithin A supports mitophagy, the removal of damaged mitochondria. NMN supports NAD+ production, which is involved in cellular energy metabolism. Ca-AKG provides alpha-ketoglutarate, an intermediate in the Krebs cycle.

The combination is designed to address mitochondrial biology at multiple levels: quality control, cellular energy metabolism, and metabolic substrate support. This multi-pathway approach is why mitochondrial health sits near the core of TimeWarp's architecture.

Not every longevity formula includes urolithin A; other compounds commonly used for mitochondrial support act through different mechanisms. Urolithin A is distinct because human trials have directly measured mitochondrial biomarkers alongside functional outcomes such as muscle strength and endurance.

Bioavailability and Food Sources: The Pomegranate Reality

Pomegranates, berries, and walnuts contain ellagitannins and ellagic acid, dietary precursors that gut bacteria can metabolize into urolithins. But conversion varies substantially from person to person.

In a controlled dietary-exposure study, roughly 40% of participants were classified as urolithin A producers following pomegranate consumption, while direct supplementation produced substantially more consistent exposure across participants. (Singh et al., European Journal of Clinical Nutrition 2022)

This is why supplementation with pre-formed urolithin A is useful: it bypasses variation in microbial conversion and provides a defined dose regardless of an individual's urolithin-producing capacity.

What the Research Shows: Evidence and Caveats

Clinical evidence grade: moderate to high. Urolithin A has moved well beyond preclinical research and has now been evaluated across multiple randomized human trials.

What is well supported:

• Mitochondrial biomarker and gene-expression changes in older adults (Andreux et al., Nature Metabolism 2019)

• Muscle strength and exercise-performance improvements in adults ages 40 to 64 (Singh et al., Cell Reports Medicine 2022)

• Muscle-endurance improvements in adults ages 65 to 90 (Liu et al., JAMA Network Open 2022)

• Early evidence of changes in CD8+ T-cell populations and metabolism in adults ages 45 to 70 (Denk et al., Nature Aging 2025)

• Favorable short-term tolerability across published human trials

What remains unclear:

• Long-term effects: most published intervention trials have run four weeks to four months. Effects over years are not established.

• Population specificity: most of the established clinical evidence comes from middle-aged and older adults. A small 2025 randomized pilot trial also studied academy soccer players, but evidence in healthy younger adults remains limited.

• Individual variation: response may vary, and there is not yet an established clinical biomarker for predicting who will benefit most.

• Optimal dose: human trials have studied both 500mg and 1000mg daily, but there is no definitive head-to-head evidence establishing one universally optimal dose.

Study Design Considerations

The Andreux trial was designed primarily to assess safety and pharmacodynamic biomarkers in sedentary older adults, so it was not intended to establish improvements in strength or exercise performance. The Singh and Liu trials extended the evidence to functional outcomes over four months. The 2025 Denk immune trial adds a new biological domain but remains small and awaits independent replication.

Dose Considerations: 500mg vs. 1000mg

Human trials have studied both 500mg and 1000mg daily. Andreux included both doses and demonstrated changes in mitochondrial biomarkers. Singh also included both doses and reported functional improvements. Liu and Denk studied 1000mg daily.

There is no head-to-head trial designed to identify one best dose across every outcome. TimeWarp includes 500mg, directly matching one of the clinically studied doses in the Andreux and Singh trials.

Key Research Findings

Research Update: What Has Been Published More Recently?

A 2026 systematic review and meta-analysis evaluated five randomized controlled trials involving 236 participants and provides a useful snapshot of the growing human evidence base. The trials reported signals across muscle strength, endurance, aerobic capacity, and mitochondrial biomarkers, although differences in study populations, doses, and outcome measures limited how many outcomes could be formally pooled. The six-minute walk test was the only outcome suitable for quantitative meta-analysis and showed a favorable but statistically inconclusive effect. The review concluded that larger and more standardized trials are still needed to determine which effects are most reproducible and which populations benefit most. (Dao et al., Frontiers in Nutrition 2026)

Research published in 2026 is also expanding the mechanistic picture. A Nature Communications study identified effects of urolithin A on AHR-NLRP6 signaling, mucosal immunity, and intestinal barrier biology, including experiments using human intestinal biopsies. A separate Experimental & Molecular Medicine study reported effects on AMPK-mTOR signaling, mitophagic flux, mitochondrial function, and cardiac remodeling in an HFpEF mouse model. These findings are mechanistically interesting, but they are not new human supplementation trials and do not change the clinical conclusions summarized above. (Ghosh et al., Nature Communications 2026; Song et al., Experimental & Molecular Medicine 2026)

FAQ

What is urolithin A?

Urolithin A is a metabolite produced by gut bacteria from dietary ellagitannins and ellagic acid found in foods such as pomegranates, berries, and walnuts. It can also be taken as a pre-formed supplement, which bypasses microbial conversion and provides a defined dose.

Can I get enough urolithin A from food?

Not reliably. People vary substantially in their ability to generate urolithin A from dietary precursors. In a controlled pomegranate-exposure study, roughly 40% of participants were classified as urolithin A producers, while direct supplementation produced much more consistent exposure. Food also does not provide anything close to a 500mg dose of pre-formed urolithin A.

How long before I notice benefits from urolithin A?

Human trials have detected mitochondrial biomarker changes within four weeks, while functional outcomes such as muscle strength and endurance have been studied over four months. Whether someone subjectively "feels" a difference, and how quickly, is less well established and likely depends on baseline age, fitness, and health.

Does urolithin A work for younger people?

Most of the established human evidence comes from middle-aged and older adults: Singh enrolled adults 40 to 64, Denk enrolled adults 45 to 70, Andreux enrolled adults 61 to 85, and Liu enrolled adults 65 to 90. Younger populations are beginning to be studied. A small 2025 randomized pilot trial in academy soccer players found improvements in some performance measures after six weeks of urolithin A supplementation, but the study was small and conducted during a structured preseason training program. We still do not know whether healthy adults in their 20s and 30s experience the same magnitude of benefit seen in older populations. (Monsalve Acevedo et al., Frontiers in Nutrition2025)

Is urolithin A safe?

Published human trials have generally found urolithin A to be well tolerated at the doses studied. The Andreux first-in-human trial specifically evaluated safety and tolerability, and subsequent randomized trials did not identify major safety signals over their study durations. Longer-term safety beyond the durations studied in controlled trials is less established. People with medical conditions or taking medications should discuss supplementation with a healthcare provider.

How does urolithin A compare to other mitochondrial supplements?

Urolithin A is distinct because its clinical research directly evaluates mitochondrial biomarkers and mitophagy-related biology. Other mitochondrial supplements work through different mechanisms: CoQ10 participates in electron transport, carnitine helps transport fatty acids into mitochondria, and alpha-lipoic acid functions as a redox-active cofactor and antioxidant. These are different mechanisms rather than interchangeable versions of the same intervention.

Is urolithin A from TimeWarp different from other brands?

TimeWarp includes 500mg of urolithin A in the Energize Pill, matching a dose studied in the Andreux 2019 and Singh 2022 randomized trials. It is formulated alongside NMN and other compounds selected to support complementary aspects of mitochondrial and cellular metabolism.

Key Takeaways

• Urolithin A is clinically studied. Randomized human trials have reported changes in mitochondrial biomarkers, muscle strength and endurance, and, more recently, immune-cell biology.

• 500mg is a clinically studied dose. Both 500mg and 1000mg have been used in human trials. TimeWarp's 500mg dose matches doses studied by Andreux and Singh.

• Mitophagy is central to the mechanism. Urolithin A has been linked to mitochondrial quality-control pathways in preclinical research, while human trials have demonstrated changes in mitochondrial biomarkers and mitophagy-related signatures.

• Food conversion varies substantially. Gut microbiome composition influences whether and how much urolithin A a person produces from dietary precursors.

• Evidence is strongest from midlife onward. Most of the established clinical evidence comes from adults ages 40 and older, while early studies in younger athletic populations are beginning to broaden the evidence base.

• The 2025 immune findings are promising but early. The Denk trial suggests effects on age-related immune-cell phenotypes, but replication is needed.

• TimeWarp uses urolithin A as part of a broader mitochondrial strategy. Protocol 01 pairs it with NMN and Ca-AKG, which address complementary aspects of mitochondrial and cellular metabolism.

Author Bio

Dr. Danielle Orozco Cosio is Customer Success and GTM Lead at MyDose AI and a member of the TimeWarp Labs Scientific Advisory Board. She earned her PhD in Brain and Cognitive Sciences at MIT, where she worked in the Synthetic Neurobiology group, and previously conducted clinical research at Massachusetts General Hospital. Her work spans neuroscience, clinical research, and the translation of emerging health technologies into real-world use.

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease. Consult your healthcare provider before starting any supplement regimen.