Your mitochondria depend on a steady flow of raw materials to keep energy production efficient. One of the most promising of these is Urolithin A, a postbiotic created by gut microbes from ellagitannins found in pomegranates and other foods. But here’s the real question: does the peel or the fruit of the pomegranate provide more of what your body needs to make Urolithin A? The answer matters if you want reliable mitochondrial support.

The Power of Pomegranate

Pomegranate has been used for centuries as a health-promoting fruit. Most people are familiar with the arils — the ruby seeds you eat fresh or in juice — which contain vitamin C, potassium, and fiber. They also contain ellagitannins, the polyphenols your gut microbes can convert into Urolithin A.

But the nutritional story doesn’t stop there. The peel, which is often discarded, turns out to be an even richer source of these critical compounds. Modern food science has confirmed that the peel is packed with punicalagin and ellagic acid, the key precursors for Urolithin A. Reviews published in Food Chemistry and Frontiers in Pharmacology highlight that peel extracts consistently contain more than double the phenolic content of arils or juice. This makes the peel a potent, if overlooked, part of the fruit when it comes to Urolithin A potential.

Why the Peel Wins for Urolithin A Precursors

When scientists measure ellagitannin content across different parts of the pomegranate, the peel consistently comes out on top. Studies comparing peel, seeds, and arils show:

• Peel: The richest source of punicalagin and ellagic acid, both directly tied to Urolithin A production.
  
  

• Arils and juice: Contain these compounds, but at much lower concentrations and more subject to dilution during processing.
  
  

• Seeds: High in oils and other bioactive compounds, but not a significant source of ellagitannins.
  
  

This matters because without an adequate supply of ellagitannins, even someone with the right microbiome may not generate enough Urolithin A to impact health outcomes.

Human Variability and Microbiome Conversion

Not everyone can take advantage of ellagitannins in the same way. Researchers categorize people into urolithin metabotypes:

• UM-A: Strong producers of Urolithin A.
  
  

• UM-B: Producers of Urolithin A alongside other metabolites like Urolithin B or isourolithin A.
  
  

• UM-0: Non-producers who make little to no Urolithin A.
  
  

Up to 40 percent of the population falls into the UM-0 category, meaning they cannot generate meaningful levels of Urolithin A from food, peel included. This explains why supplementation with direct Urolithin A has become a focus for consistency and measurable results.

Food vs Supplement: What the Studies Show

Whole foods should always form the foundation of health, but if your goal is specifically to achieve circulating levels of Urolithin A, supplements have a clear edge. A randomized crossover study published in the European Journal of Clinical Nutrition in 2022 compared a serving of pomegranate juice with a 500 mg Urolithin A supplement. The supplement produced six times higher plasma levels of Urolithin A and delivered those levels consistently across all participants. Juice, on the other hand, only raised Urolithin A in about 40 percent of subjects, reflecting microbiome variability.

This distinction is important because all the major human trials that have shown benefits from Urolithin A — such as improvements in muscle endurance, mitochondrial biomarkers, and exercise capacity — have used standardized supplementation. For example, a 2019 study in Nature Metabolism demonstrated that Urolithin A was safe and improved mitochondrial gene expression in older adults. A 2022 trial in JAMA Network Open found better muscle endurance after four months of daily Urolithin A, while a Cell Reports Medicine trial that same year showed stronger exercise performance and shifts in mitochondrial proteins in sedentary middle-aged adults.

When Whole Foods Still Matter

Even if peel or supplements deliver more precursors, the arils and juice of the pomegranate remain valuable. They provide fiber, potassium, vitamin C, and a wide array of polyphenols that support cardiovascular and metabolic health. Walnuts, raspberries, and strawberries also contain ellagitannins and should be part of a varied diet. For those who can produce Urolithin A naturally, a diet rich in these foods can help. For low producers, however, supplementation is the most reliable way to experience the benefits observed in clinical trials.

Practical Tips

• If you rely on food: Choose whole pomegranates when in season. Eating arils or drinking small amounts of 100 percent juice supports general wellness, but remember peel contains the densest concentration of ellagitannins.
  
  

• If you supplement: Look for products that source Urolithin A from pomegranate peel. This ensures potency and consistency.
  
  

• Stay consistent: Clinical benefits were observed after 8 to 16 weeks of daily intake, not overnight.
  
  

• Combine approaches: Use whole foods for broad nutrition and supplementation for reliable Urolithin A exposure.
  
  

• Work with your clinician: Especially if you have health conditions or take medications, professional guidance helps tailor the right approach.
  
  

Supporting Mitochondrial Health with BioLithin

BioLithin was designed around this science. It combines Urolithin A, Urolithin B, and taurine, sourcing its urolithins from pomegranate peel, the richest and most efficacious portion of the plant. By doing so, it ensures consistent delivery of Urolithin A precursors without depending on your microbiome. With taurine added for mitochondrial support, BioLithin provides a comprehensive approach to sustaining energy, muscle function, and resilience over time.

Key Takeaway

Pomegranate is a powerful food, but when it comes to Urolithin A precursors, the peel clearly outperforms the fruit. While arils and juice are nutritious, they deliver less of the compounds that drive Urolithin A production, and microbiome variability makes outcomes unpredictable. Standardized supplements sourced from peel ensure reliable exposure and align with the clinical trials showing improvements in endurance, mitochondrial biomarkers, and recovery. Together, food and supplementation create the best strategy to support your mitochondria and overall vitality.

This content is for informational purposes only and is not a substitute for professional medical advice. Results vary by individual, and research is ongoing. Always consult a healthcare professional before starting a new supplement regimen.