Creatine, unless you cannot train. It is the only compound in this pair graded Strong: meta-analyses of resistance-training trials show roughly +1.4 kg lean tissue mass and real strength gains in older adults. Urolithin A's muscle trials are smaller, shorter and almost entirely manufacturer-funded. Both need training to matter, and neither has bone or lifespan data in its favour.
| Compared on | Creatine | Urolithin A |
|---|---|---|
| Evidence grade | Strong evidence | Moderate evidence |
| What it is | Creatine is a nitrogen-containing compound that the body synthesizes from the amino acids arginine, glycine, and methionine, and also obtains from meat and fish; roughly 95% is stored in skeletal muscle. | Urolithin A is a natural compound produced by gut bacteria from ellagitannins and ellagic acid, dietary polyphenols found in pomegranates, walnuts, and berries. |
| Best human evidence | “Creatine supplementation resulted in greater increases in lean tissue mass (mean difference =1.37 kg [95% CI =0.97-1.76];<0.00001), chest press strength (standardized mean difference [SMD]…” Open Access J Sports Med 2017 · PMID 29138605 | “Urolithin A is a gut microbiome-derived metabolite shown to stimulate mitophagy and improve muscle function” JAMA Netw Open 2022 · PMID 35050355 |
| Dose / protocol studied | 3–5 g/day (creatine monohydrate); an optional ~20 g/day loading week works faster but isn’t required | 1,000 mg/day in most trials (500–1,000 mg/day studied) |
| Typical listed price | $44.00 | $50.00 |
| Who it suits | Anyone doing resistance training who wants the best-evidenced, cheapest ergogenic on the site — and older adults in particular. | Someone already training who wants to target mitophagy specifically, and who accepts short, industry-funded trials as the current evidence base. |
| Who should skip it | Someone hoping it will build muscle without training: gains are generally smaller when creatine is taken without exercise, and two-year trials found no bone-density benefit. | Anyone looking for the biggest effect per dollar, or for physical-function change — a 2024 systematic review found no effect on physical function. |
| Key caveat | One of the most studied supplements there is: dozens of randomized trials and meta-analyses show reliable gains in strength, power and lean muscle alongside resistance training, and it is well tolerated in healthy people. The strong evidence is for muscle and exercise performance; cognitive, bone and healthy-aging benefits are promising but less settled. It supports training — it is not a treatment. | Several small, well-controlled randomized trials show improved muscle endurance and strength, lower inflammatory markers, and younger-looking immune-cell profiles, with an excellent safety record. But nearly all are short (4 months or less) and manufacturer-funded, some missed their primary endpoints, and there is no long-term disease or lifespan data. Most people cannot reliably make urolithin A from food — the rationale for direct supplementation. |
Urolithin A lists at about 1.1× the price of Creatine. Prices are the typical listed prices in our catalog, not live Amazon prices, and a true cost-per-studied-dose is not shown because our catalog does not record servings per container — we would have to guess, so we don't.
Both target age-related muscle decline from different directions: creatine buffers ATP, urolithin A recycles damaged mitochondria. One of them has thirty years of trials.
Creatine. A meta-analysis found creatine plus resistance training produced greater increases in lean tissue mass (mean difference 1.37 kg), chest-press strength and leg-press strength than training alone. A 2026 meta-analysis in postmenopausal women found leg-press gains only when at least 5 g/day was paired with training.
Urolithin A has the more relevant trial. The JAMA Network Open randomized trial in adults 65–90 reported improved muscle endurance and mitochondrial health markers. Be aware the same review literature reports no effect on physical function overall.
Creatine. A meta-analysis of 8 randomized trials found creatine improves memory modestly overall, with the largest effect in adults aged 66–76. Effects on other cognitive domains remain unclear.
Neither. Two separate two-year randomized trials in postmenopausal women found creatine did not improve bone mineral density, and a 2026 meta-analysis confirmed no bone-density effect. Urolithin A has no bone data at all.
Every positive result on this page is a result for a compound plus resistance training. In the meta-analyses, the comparison group is not sedentary — it is people doing the same training without the supplement, and the supplement's contribution is the smaller share of the effect.
Creatine also occurs naturally almost only in animal muscle, so meat and fish are the dietary route; a meat-free diet measurably lowers muscle creatine. Urolithin A cannot be obtained from food at all — gut bacteria have to make it, and many people's do not.
Each quote below is taken verbatim from the cited paper. Null and negative results are included on purpose — they are the reason a grade means anything.
“Creatine supplementation resulted in greater increases in lean tissue mass (mean difference =1.37 kg [95% CI =0.97-1.76];<0.00001), chest press strength (standardized mean difference [SMD] =0.35 [0.16-0.53];=0.0002), and leg press strength (SMD =0.24 [0.05-0.43];=0.01).”
“Meta-analysis of 8 RCTs: creatine improves memory modestly overall (SMD 0.29), with the largest effect in adults aged 66-76 (SMD 0.88).”
“Creatine supplementation more than 2 years did not improve bone health in older, postmenopausal women with osteopenia, nor did it affect lean mass or muscle function in this population.”
“Urolithin A is a gut microbiome-derived metabolite shown to stimulate mitophagy and improve muscle function”
“After 8 weeks of UA supplementation at 1 g/day, resistance-trained male athletes showed improvements in muscle strength and endurance. Additionally, UA supplementation was also associated with reduced oxidative stress levels and a decrease in inflammation response levels.”
“UA increased muscle strength and endurance, however, had no effect on anthropometrics, cardiovascular outcomes, and physical function.”
Links go to an Amazon search for the product name, not to a specific listing, so you can compare sellers, price and third-party testing yourself.
If you resistance train, creatine — it is graded Strong here and urolithin A is graded Moderate, and creatine's evidence base is far larger and independent of any manufacturer. Urolithin A is the more targeted choice if mitochondrial endurance is specifically what you want.
Less well. Across the aging literature, gains are generally smaller when creatine is taken without exercise, and the meta-analyses that show lean-mass and strength benefit all pair it with resistance training.
Trials generally use 3–5 g/day, and a 2026 meta-analysis in postmenopausal women found meaningful strength gains only when at least 5 g/day was paired with training.
That depends on what you want. For lean mass and strength, creatine has more evidence at a lower price. For mitophagy and muscle endurance specifically, urolithin A is the only compound here with direct randomized human trials — funded, in nearly every case, by the manufacturer.
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