Urolithin A vs Protein Powder: Building Muscle From Two Different Angles
Protein powder and urolithin A both show up in conversations about muscle, but they sit at opposite ends of the same problem. Protein delivers the raw material a muscle needs to rebuild. Urolithin A is aimed at the energy machinery inside the muscle cell that determines how well that material gets put to work — something that matters more, not less, as you age.
What protein powder actually does
Muscle is built and maintained through a constant turnover of protein: fibers break down with use and get rebuilt through a process called muscle protein synthesis. That rebuilding depends on a steady supply of amino acids, especially the branched-chain amino acid leucine, which acts as a trigger for the synthesis pathway. Protein powder — whey, casein, or plant blends like pea and rice — is simply a convenient, concentrated way to hit your daily protein target and deliver those amino acids around training. Whey digests quickly and is leucine-rich; casein digests slowly; plant blends are combined to round out the amino acid profile. This is well-established nutrition, and for most people who train or who are trying to preserve muscle with age, adequate protein intake is genuinely foundational.
But protein answers only one question: is the raw material available? It does not, by itself, address how efficiently the muscle cell converts that material into functional, energy-producing tissue. That conversion depends on the health of the cell's internal machinery — and that is a different problem with a different tool.
What urolithin A is aimed at instead
Urolithin A is not a protein, a source of amino acids, or a building block. It is a gut postbiotic — a compound your microbiome produces when it breaks down ellagitannins from pomegranate, walnuts, and berries. Crucially, only some people carry the gut bacteria needed to convert those precursors into urolithin A efficiently, which is part of why direct supplementation is of interest. Its most studied biological action is supporting mitophagy: the cellular quality-control process that identifies worn-out mitochondria and recycles them so healthier ones can take their place.
Mitochondria are the energy generators inside muscle cells, and muscle is one of the most mitochondria-dense tissues in the body. With age and inactivity, mitochondrial quality tends to decline, which can leave muscle cells less efficient even when protein intake is perfectly adequate. The idea behind urolithin A is to support the housekeeping side of that equation. It is worth being precise: this is about supporting cellular quality, not about "replacing" protein or building bulk directly. Our mitochondrial health overview explains why muscle depends so heavily on this machinery.
What the human evidence shows — and what it doesn't
Urolithin A is a promising compound, but its human research is still emerging. We will keep the strongest human findings separate from the newer ones and from the animal work, because that distinction is where a lot of marketing goes wrong.
Proven in humans first
The first-in-human study, Andreux and colleagues (2019, Nature Metabolism), found urolithin A safe and well tolerated up to 1,000 mg per day and showed it produced a mitochondrial gene-expression signature — evidence it engages the pathways it targets. For muscle specifically, Liu, D'Amico and colleagues (2022, JAMA Network Open) studied older adults over roughly four months and reported improvements in muscle endurance. Singh and colleagues (2022, Cell Reports Medicine) studied middle-aged adults for four months across 500 mg and 1,000 mg arms and reported benefits for muscle strength and exercise performance. These are the closest thing to muscle-relevant human evidence urolithin A has.
Newer human work
A 2024 randomized controlled trial in the Journal of the International Society of Sports Nutrition examined resistance-trained men over eight weeks — a population more like dedicated lifters. A 2025 trial in Nature Aging (about 28 days) reported support for immune-cell mitochondrial health in midlife adults in the context of age-related inflammation, and there is a 2025 trial in distance runners. These broaden the picture, but many are short or population-specific. A 2024 systematic review in Ageing Research Reviews concluded the human evidence is still emerging — a fair summary.
Preclinical (animal and cell) research
The original mechanistic work, Ryu and colleagues (2016, Nature Medicine), is preclinical: it showed urolithin A triggered mitophagy, extended lifespan in C. elegans, and improved muscle measures in rodents. That research is why muscle became a focus, but animal results are not proof of human outcomes and shouldn't be presented as such.
Do you choose one? No — they stack
This is not an either/or. Protein and urolithin A address different halves of the same goal, and there is no biological conflict between them. Adequate protein makes sure the building blocks are present. Urolithin A is aimed at supporting the mitochondrial quality that helps muscle cells use those building blocks efficiently, particularly as the cellular machinery ages. If you are serious about preserving strength and function through midlife and beyond, the sensible approach is to get your protein intake right first — that is non-negotiable and does the heavy lifting — and consider urolithin A as a complementary daily habit on top of it, not a substitute.
A realistic expectation matters here too. Protein you can feel working over days as recovery and training capacity respond. Urolithin A is not like that: it produces no acute sensation, and its studied effects unfolded over weeks to months of daily use. Our how long it takes to work guide sets honest timelines.
A note on transparency: SOMA HEALTH makes a urolithin A supplement, so we are a competitor in this category and have a stake in it — we've tried to keep the framing above honest about human-proven versus emerging evidence. And because muscle loss and weakness can have medical causes, none of this is a treatment for any condition. If you are dealing with unexplained weakness or muscle loss, see your doctor rather than relying on a supplement.
New to the compound? Start with our urolithin A guide, compare formats in our best urolithin A gummies roundup, and review urolithin A benefits for the full structure-function picture.
Frequently asked questions
Can urolithin A replace my protein powder?
No. Protein supplies the amino acids your muscles need to rebuild; urolithin A supplies none. They address different parts of muscle maintenance and are best thought of as complementary, not interchangeable.
Should I take them together?
There is no known conflict between adequate protein intake and urolithin A. Many people do both — protein around training, urolithin A as a consistent daily habit. Run your full regimen past a healthcare provider.
Does urolithin A build muscle on its own?
It is not a builder. Human trials have reported support for muscle strength and endurance measures, but urolithin A supports mitochondrial quality rather than directly adding tissue. Training and protein do the building.
How much urolithin A should I take?
Human studies used 500 to 1,000 mg per day, with 1,000 mg at the top of the range. SOMA HEALTH Urolithin A Gummies provide 1,000 mg in a four-gummy serving. See our dosage guide.
Is urolithin A safe alongside a high-protein diet?
The first-in-human study reported it was safe and well tolerated up to 1,000 mg per day, and it is not a protein. Still, check with your doctor before combining supplements, especially if you have kidney concerns that affect protein intake.
I already eat walnuts and pomegranate — do I need it?
Those foods provide the precursors, but only some people convert them to urolithin A efficiently because of differences in gut bacteria. Supplementing delivers the compound directly.
When will I notice anything?
Urolithin A produces no immediate sensation. The muscle-relevant human trials ran about four months, so consistency over weeks to months is the right expectation.
*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. This guide is educational and is not a substitute for advice from a qualified healthcare provider.
A clinically studied 1,000 mg dose of Urolithin A in one simple daily gummy — to support mitophagy, muscle strength, and cellular energy.
Shop SOMA Urolithin A Gummies →