Does Urolithin A Reduce Inflammation? What the Research Shows

Urolithin A sits at an unusual intersection of nutrition science and longevity research. It is not something you eat directly, and it is not something most plants make. Instead it is produced inside your gut when certain bacteria break down a family of large polyphenols called ellagitannins, which are abundant in pomegranates, walnuts, pecans, and berries. For decades this metabolite was a biochemical footnote. Then researchers discovered that it switches on mitophagy, a quality-control process that keeps cells energetically healthy, and interest exploded. Because faulty mitochondria and chronic inflammation feed each other, the question of whether urolithin A reduces inflammation has become one of the more interesting threads in the supplement literature, and unlike many trendy compounds it now rests on actual human trials.

What Urolithin A Is and Where It Comes From

Urolithin A is a metabolite, not a nutrient you consume directly. The foods people associate with it, pomegranate most of all, do not actually contain urolithin A. What they contain are ellagitannins and ellagic acid, bulky polyphenols that the body cannot absorb well on their own. When these compounds reach the large intestine, specific gut bacteria convert them in a multi-step process into urolithins, of which urolithin A is the most biologically active. This is why urolithin A is described as a postbiotic, a beneficial compound generated by the microbiome rather than supplied ready-made by food.

The catch is that not everyone's gut produces it. The bacterial machinery needed to turn ellagitannins into urolithin A is not present in every person's microbiome, so two people eating the same pomegranate can end up with very different amounts of the active compound in their blood. Researchers describe people as urolithin producers or non-producers depending on their gut bacteria, and a meaningful share of the population makes little or none. This variability is one of the main reasons direct urolithin A supplements were developed, since a standardized dose bypasses the lottery of whether your microbiome happens to carry the right bacteria. According to a review in Trends in Molecular Medicine, urolithin A enhances cellular health by increasing mitophagy and mitochondrial function while reducing detrimental inflammation, and recent clinical trials support its benefits in human muscle (D'Amico et al., 2021; DOI).

The dietary sources worth knowing are pomegranate, walnuts, pecans, and various berries such as raspberries and strawberries. Pomegranate and walnuts are the richest practical sources of the ellagitannin precursors. Eating these foods regularly is sensible for many reasons, but if the goal is a reliable, measurable dose of urolithin A specifically, food alone is an unpredictable delivery system because of the producer and non-producer issue described above. That gap between dietary precursor and absorbed metabolite is exactly what makes urolithin A a more complicated story than a simple "eat more pomegranate" message.

How Urolithin A Connects to Inflammation

The central link between urolithin A and inflammation runs through mitochondria. Mitochondria are the energy-producing structures inside nearly every cell, and like any hardworking machinery they accumulate damage over time. Mitophagy is the housekeeping process that identifies these damaged mitochondria and recycles them before they become a liability. When mitophagy slows down, which happens with age and with chronic metabolic stress, damaged mitochondria pile up and begin leaking molecules such as mitochondrial DNA and reactive oxygen species into the cell. The immune system reads these leaked molecules as danger signals, and the result is a low-grade, smoldering inflammatory response.

Urolithin A re-activates mitophagy, which is why its anti-inflammatory potential is biologically plausible rather than speculative. By helping cells clear out dysfunctional mitochondria, urolithin A reduces the supply of those internal danger signals, and with fewer alarms going off, the inflammatory tone of the tissue settles. This is a fundamentally different mechanism from an herb that simply blocks an inflammatory enzyme. Urolithin A works upstream, addressing one of the root causes of age-related and metabolic inflammation rather than only muffling its downstream output. The concept has become influential enough that researchers now use the term inflammaging to describe the slow rise in baseline inflammation that accompanies declining mitochondrial quality control.

Laboratory work points to a specific inflammatory pathway. In a mouse study of fructose-driven kidney inflammation, urolithin A restored mitophagy and in turn blunted activation of the STING-NLRP3 inflammasome, a key trigger of the inflammatory cascade, which lowered production of the pro-inflammatory cytokines IL-1 beta, IL-6, and TNF-alpha (Zhang et al., 2022; DOI). The NLRP3 inflammasome is one of the most important switches in chronic inflammation, so a compound that quiets it by improving mitochondrial health is mechanistically compelling. The caveat is that this particular study was in animals, so its value is in explaining how urolithin A might work rather than in proving the effect in people, which is where the human trials come in.

What the Human Evidence Shows

Urolithin A has cleared a bar that most supplements never reach: multiple randomized controlled trials in humans. The first-in-human study, published in Nature Metabolism, gave healthy but sedentary older adults either a single dose or daily doses of 500 mg or 1,000 mg over four weeks. It found the compound safe and well absorbed, and at those doses it measurably shifted skeletal muscle mitochondrial gene expression, producing what the authors called a molecular signature of improved mitochondrial and cellular health (Andreux et al., 2019; DOI). That trial established safety and target engagement, setting the stage for larger studies that looked at inflammation directly.

The most important inflammation finding comes from a four-month randomized, placebo-controlled trial in middle-aged adults. Published in Cell Reports Medicine, the study reported a roughly 12 percent improvement in muscle strength with urolithin A, and critically, levels of C-reactive protein were significantly lower in the urolithin A group than in the placebo group, which the authors interpreted as a sign of reduced inflammation and higher mitochondrial efficiency (Singh et al., 2022; DOI). Because CRP is the same general marker that at-home inflammation tests measure, this result is directly relevant to anyone thinking about urolithin A as a wellness intervention rather than just an athletic one.

A separate trial in athletes reinforces the CRP signal in a very different population. In an eight-week randomized, double-blind study of resistance-trained male athletes taking 1 gram of urolithin A daily, the supplement group showed a significant reduction in CRP compared with placebo, a difference of about 0.79 mg/L (p = 0.032), along with improvements in muscle endurance and reduced oxidative stress (Zhao et al., 2024; DOI). Seeing a lower CRP relative to placebo in hard-training athletes, whose intense exercise naturally pushes inflammatory markers up, is a notable result because it suggests urolithin A helped the body manage the inflammatory load of training. A 2025 trial in highly trained distance runners similarly concluded that four weeks of urolithin A aided recovery by downregulating inflammatory pathways in muscle and reducing markers of muscle damage, even though it did not improve race performance.

The honest summary is encouraging but measured. The human trials are consistent in pointing toward lower inflammation, and the CRP findings in particular show up across both aging and athletic populations, which is reassuring. At the same time, the studies are still relatively small, several are short in duration, and a number of the foundational trials were conducted by or with the company that developed the leading branded form of urolithin A, which is a legitimate consideration when weighing the evidence. The direction is clear and the mechanism is well supported, but urolithin A has not yet accumulated the decades of large independent trials that cement a health claim. It is a strong candidate rather than a settled conclusion.

Dosing, Sources, and Practical Considerations

The doses used in positive human trials cluster around 500 mg to 1,000 mg of urolithin A per day. The landmark muscle and CRP trials used 500 mg and 1,000 mg daily, and the athlete studies used roughly 1 gram daily, so that range reflects what the evidence actually tested. Benefits in these studies appeared over weeks to months rather than days, which fits the mechanism: rebuilding mitochondrial quality control is a gradual process, not an overnight switch. Anyone considering urolithin A should think in terms of sustained daily use rather than occasional dosing.

Food and supplements are not interchangeable here. Because only some people's gut bacteria convert ellagitannins into urolithin A efficiently, relying on pomegranate and walnuts alone gives an unpredictable and usually much smaller dose than the trials used. For people who are non-producers, food may deliver almost no urolithin A at all. Direct supplements were created specifically to sidestep this problem and deliver a consistent amount regardless of microbiome makeup. This does not mean supplements are necessary for everyone, but it does mean the "just eat the fruit" shortcut does not reliably reproduce the research conditions.

Safety in the trials has been favorable, but the usual supplement caution applies. Across the published human studies, urolithin A at these doses was well tolerated with a clean safety profile and no serious adverse effects reported. Even so, it is a bioactive compound, long-term data are limited, and it has not been studied in pregnancy, breastfeeding, or in combination with most medications. As with any supplement, anyone who is pregnant or breastfeeding, taking prescription medication, or managing a chronic condition should talk with a healthcare provider before starting it, and no supplement should be used as a substitute for medical care.

How Urolithin A Fits Into an Anti-Inflammatory Approach

Urolithin A is best understood as a targeted addition to a foundation, not the foundation itself. The compound works on a real and important mechanism, but the largest and most durable drivers of inflammation remain the basics: a dietary pattern rich in vegetables, legumes, whole grains, olive oil, and omega-3 fats; regular physical activity; sufficient sleep; a healthy body composition; and managed stress. Interestingly, eating ellagitannin-rich foods like pomegranate and walnuts supports this picture from two directions at once, supplying the raw material for urolithin A in people who can make it while also delivering fiber and other polyphenols that benefit the gut. A supplement that nudges mitochondrial health and CRP in the right direction is a worthwhile tool, but it sits on top of lifestyle, not in place of it.

This is exactly where measurement earns its keep. Because CRP reflects the combined inflammatory output of diet, movement, sleep, stress, body composition, and yes, mitochondrial health, it captures the net effect of everything you are doing rather than the contribution of any single supplement. If you add urolithin A as part of a broader anti-inflammatory routine, tracking CRP over time turns a guess into something you can actually observe. You cannot isolate the supplement's specific effect from a home test, and you should not try to, but you can watch whether your overall direction is improving. Checking CRP periodically makes the invisible process of chronic inflammation visible, and a persistent elevation is always worth discussing with a healthcare provider rather than attributing to any one food or compound.

Sources

• Singh A, D'Amico D, Andreux PA, et al. Urolithin A improves muscle strength, exercise performance, and biomarkers of mitochondrial health in a randomized trial in middle-aged adults. Cell Reports Medicine. 2022;3(5):100633. pubmed.ncbi.nlm.nih.gov/35584623
• Andreux PA, Blanco-Bose W, Ryu D, et al. The mitophagy activator urolithin A is safe and induces a molecular signature of improved mitochondrial and cellular health in humans. Nature Metabolism. 2019;1(6):595-603. pubmed.ncbi.nlm.nih.gov/32694802
• Zhao H, Zhu H, Yun H, et al. Assessment of Urolithin A effects on muscle endurance, strength, inflammation, oxidative stress, and protein metabolism in male athletes with resistance training: an 8-week randomized, double-blind, placebo-controlled study. Journal of the International Society of Sports Nutrition. 2024;21(1):2419388. pubmed.ncbi.nlm.nih.gov/39487653
• D'Amico D, Andreux PA, Valdés P, et al. Impact of the Natural Compound Urolithin A on Health, Disease, and Aging. Trends in Molecular Medicine. 2021;27(7):687-699. pubmed.ncbi.nlm.nih.gov/34030963
• Zhang C, Song Y, Chen L, et al. Urolithin A Attenuates Hyperuricemic Nephropathy in Fructose-Fed Mice by Impairing STING-NLRP3 Axis-Mediated Inflammatory Response. Frontiers in Pharmacology. 2022;13:907209. pubmed.ncbi.nlm.nih.gov/35784701

Frequently Asked Questions

Does urolithin A reduce inflammation?

Current evidence suggests it can. A four-month randomized trial in middle-aged adults found significantly lower C-reactive protein (CRP) with urolithin A compared with placebo, and a separate trial in athletes found a significant CRP reduction relative to placebo as well. The leading mechanism is that urolithin A reactivates mitophagy, the cellular recycling of damaged mitochondria, which reduces the internal danger signals that drive chronic inflammation. The research is still relatively young and trials are small, so urolithin A is best used as part of a broader anti-inflammatory lifestyle rather than as a standalone treatment.

What foods contain urolithin A?

No food contains urolithin A directly. Instead, foods like pomegranate, walnuts, pecans, and berries contain ellagitannins and ellagic acid, which gut bacteria convert into urolithin A in the colon. The important catch is that not everyone's microbiome carries the bacteria needed to make this conversion efficiently, so some people produce very little urolithin A from food. This variability between producers and non-producers is the main reason standardized urolithin A supplements were developed.

How does urolithin A affect CRP?

In human trials, urolithin A has been associated with lower CRP. A 2022 randomized trial in middle-aged adults reported significantly lower CRP in the urolithin A group than in the placebo group, and a 2024 trial in resistance-trained athletes found a significant CRP reduction relative to placebo of about 0.79 mg/L. CRP reflects total body inflammation from diet, sleep, activity, stress, body composition, and mitochondrial health combined, so urolithin A is one input among many. CRP is a general wellness marker, and persistent elevations should be discussed with a healthcare provider.

Is urolithin A safe to take?

In published human trials, urolithin A at doses of 500 mg to 1,000 mg per day was well tolerated with a favorable safety profile and no serious adverse effects reported. However, long-term data are still limited, and it has not been well studied in pregnancy, breastfeeding, or alongside most medications. Anyone who is pregnant or breastfeeding, taking prescription medication, or managing a chronic condition should consult a healthcare provider before starting it.