Fatty15 vs Timeline (Urolithin A / Mitopure): Two Different Longevity Bets
Fatty15 and Timeline’s Mitopure (urolithin A) are both premium “healthy aging” supplements that show up in the same conversations, so people naturally compare them. But like most of these matchups, they target different biology. Fatty15 delivers C15 for cell-membrane and metabolic health; Mitopure delivers urolithin A to support mitochondrial quality (specifically a process called mitophagy). Here’s how to choose.
The Core Difference
Mitopure (urolithin A) is researched primarily for mitochondrial health and muscle function, it’s thought to support “mitophagy,” the cellular clean-up of damaged mitochondria. Fatty15 (C15) is researched for cell-membrane stability and metabolic/liver markers. Different targets, different mechanisms.
Research note: In elite male distance runners, four weeks of urolithin A did not significantly improve 3000 m time-trial performance [6].
Fatty15 vs Mitopure: Side-by-Side
| Fatty15 (C15) | Timeline Mitopure (Urolithin A) | |
|---|---|---|
| Key ingredient | Pentadecanoic acid | Urolithin A |
| Primary focus | Cell membranes, metabolic/liver | Mitochondria, muscle function |
| Notable research | Membrane stability, metabolic markers | Muscle strength/endurance trials |
| Source | Synthesized, vegan-friendly fatty acid | Urolithin A, a metabolite made by gut microbes |
| Price tier | Premium | Premium |
Which Longevity Supplement Should You Pick?
- Choose Fatty15 (C15) if you’re interested in the early research on C15 and metabolic and liver markers, and in the “essential fatty acid” hypothesis, which an independent review calls controversial [1][2].
- Choose Mitopure (urolithin A) if your priority is mitochondrial support and muscle/physical function, which has some of the more notable human trial data in the space.
- Both is possible, they don’t overlap, but both are premium-priced, so most people start with the one that matches their main goal.
If you lean toward C15, remember you can get the molecule affordably via a generic pentadecanoic acid supplement rather than the branded product, our Fatty15 review covers that trade-off.
What Is Actually in Each Product
Before comparing biology, compare the labels. On its product page, Fatty15 lists 100 mg of pure pentadecanoic acid (C15) per capsule and says to start with one or two capsules a day, with or without food. Its FAQ states that the ingredient, FA15, is made from scratch (synthesized) to match the C15 found in nature, and describes it as vegan-friendly with no dairy or other animal products. Timeline’s Mitopure softgel page lists a recommended dose of 500 mg of Mitopure, taken as two vegan softgels daily, with 60 softgels to a month’s supply, and recommends a minimum of 4 months of use.
Urolithin A itself is described in the published literature as a natural, microflora-derived metabolite, meaning gut bacteria produce it. C15 is a fatty acid found in dairy fat, where it is a small share of the fatty acids, and the body can also produce some from gut-derived propionate. So both molecules have a natural origin story, but neither product is simply a food extract. The Mitopure page compares its plasma levels to pomegranate juice rather than saying the capsule is made from pomegranate.
What Human Trials Have Measured
The two ingredients are at different stages of human research, and it helps to be specific about what each trial tested.
Walking distance rose on urolithin A and on placebo alike
Both longevity supplements in this comparison rest on small trials with mixed results.
Mean increase in 6-minute walk distance after 4 months in 66 adults aged 65 to 90. Source: Liu et al., JAMA Network Open 2022.
Data table
| Item | Value |
|---|---|
| Urolithin A, 1,000 mg a day | 60.8 m |
| Placebo | 42.5 m |
Chart: c15hub.com: Walking distance rose on urolithin A and on placebo alike
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Urolithin A
- A first-in-human trial in Nature Metabolism (2019) gave healthy, sedentary older adults urolithin A as a single dose or for 4 weeks. The primary outcome was safety, which was favorable, and doses of 500 mg and 1,000 mg changed plasma acylcarnitines and muscle mitochondrial gene expression.
- A 2022 trial in JAMA Network Open randomized 66 adults aged 65 to 90 to 1,000 mg of urolithin A or placebo for 4 months. The primary endpoints, 6-minute walk distance and maximal muscle ATP production in the hand, were not significantly different from placebo. Muscle endurance in two muscles improved at 2 months, and plasma markers including C-reactive protein fell. The authors called for confirmation.
- A 2022 trial in Cell Reports Medicine in middle-aged adults reported roughly 12 percent greater muscle strength with urolithin A over 4 months, along with what the authors called clinically meaningful improvements in aerobic endurance and a 6-minute walk test. Its primary endpoint, peak power output, did not improve significantly.
C15
- A 2024 randomized, double-blind trial in the Journal of Nutrition (Robinson et al.) gave 200 mg of C15 or placebo daily for 12 weeks to 30 young adults with overweight or obesity. Its primary objective was the change in circulating C15, which rose significantly more than on placebo, with no significant adverse events. In the half of the treated group whose level ended above 5 micrograms per mL, liver enzymes fell and hemoglobin rose, a subgroup finding the authors said warrants further study.
- A 2024 trial in the American Journal of Clinical Nutrition (TANGO) randomized 88 Chinese women with fatty liver disease to a Mediterranean-style diet with C15, the diet alone, or habitual diet for 12 weeks. Both diet groups cut liver fat and several other markers more than the control group. C15 added a further LDL-cholesterol reduction and a rise in one gut bacterium, Bifidobacterium adolescentis, while many other markers fell in all groups in parallel with weight loss.
Put plainly, urolithin A has more trials with functional endpoints such as strength and endurance, while the C15 trials so far are small and mostly establish that supplementation raises blood levels safely. Neither set shows a hard clinical outcome like fewer falls or fewer cardiovascular events.
The trial was supported by Seraphina Therapeutics, which supplied the capsules, and the split by blood level was a subgroup comparison made afterward. Apart from a drop in the liver enzyme GGT, it found no other significant changes in any secondary outcome versus placebo [3].
How the Proposed Mechanisms Differ
Urolithin A is studied as a trigger for mitophagy, the recycling of damaged mitochondria. C15 is studied on several fronts. A 2025 mechanism review in the World Journal of Biological Chemistry summarizes laboratory work indicating that C15 acts as a dual partial PPAR alpha and delta agonist, activates AMPK, suppresses mTOR and selectively inhibits an enzyme called HDAC6. The same review notes that prospective clinical outcomes are still lacking. A 2023 cell-based paper in Nutrients (Venn-Watson and colleagues) found that C15 shared 24 activities with rapamycin across human cell systems, but cell assays show patterns of activity, not proof that a capsule slows aging in a person, and the authors are affiliated with the company that commercializes the ingredient.
The practical takeaway is that the two do not compete for the same job. If you care about muscle and endurance, urolithin A has the more direct human data. If you care about the C15 hypothesis, the evidence is earlier and more mechanistic.
Cost and Review Signals as of October 2026
As of October 2026, Fatty15’s product page listed a 90-day starter kit (one time or on subscription, with refills every 90 days), a 30-day trial kit and a 360-capsule annual kit. Prices change, so check the current listing. The same page displayed a 4.8 rating from 8,519 reviews, and carried a note that some featured users were compensated. Timeline’s Mitopure softgel page displayed 4.5 out of 5 from 4,735 reviews, with 95 percent saying they would recommend it, and a 30-day money-back guarantee. A Mitopure price was not shown in the page text read for this article, so check the current listing.
Both rating displays sit on the sellers’ own sites, so treat them as marketing signals rather than independent assessments. Fatty15’s FAQ also describes a 30-day money-back guarantee on first-time trial, starter and gummy orders, which lowers the cost of testing a product but not of judging whether it did anything.
How to Decide Between Them
- Match the trial length. The urolithin A trials ran 4 months and the C15 trial ran 12 weeks, so a fair self-trial is at least that long, with a baseline you can compare against.
- Match the goal to the evidence. Muscle and endurance point toward urolithin A. Interest in the odd-chain fatty acid hypothesis points toward C15.
- Remember the dose gap. The C15 trial used 200 mg a day, double one capsule, and the urolithin A trials used 500 to 1,000 mg.
- Ask a clinician if you take medication or are pregnant or nursing, since neither is a drug and neither has been tested in every group.
Frequently Asked Questions
Is Fatty15 or Mitopure better?
Neither is universally “better”, they target different systems. Mitopure (urolithin A) focuses on mitochondria and muscle; Fatty15 (C15) focuses on cell membranes and metabolic health. Pick based on your goal.
Can I take Fatty15 and urolithin A together?
There’s no known interaction, and they address different aspects of aging (membranes vs mitochondria), so taking both is reasonable, budget permitting.
Fatty15 vs Timeline for longevity, which has better evidence?
Urolithin A (Mitopure) has some notable human trials on muscle function; C15 (Fatty15) has promising but earlier data, mostly cell-based and observational, plus two small randomized trials. Different strengths, different targets.
Do they do the same thing?
No. Fatty15 is marketed for cell-membrane and metabolic health and Mitopure for mitochondrial quality. Human data are limited for both, and they are different molecules, so they are not interchangeable [3][4][5].
Which has stronger human trial data, Fatty15 or Mitopure?
For muscle and endurance outcomes, urolithin A has more randomized trials, though at least two of them, in older adults and in middle-aged adults, missed their primary endpoints [4][5]. The C15 trials are smaller and mostly show that supplementation raises blood C15 levels safely, with some signals in liver and cholesterol markers that need confirmation.
How long should I try Fatty15 or Mitopure before judging it?
The published trials ran 12 weeks for C15 and about 4 months for urolithin A, so a few months of consistent use is a fair test, ideally with baseline blood work reviewed with a clinician.
Are the review ratings for Fatty15 and Mitopure independent?
No. The ratings quoted here were displayed on each brand’s own site as of October 2026, so they are useful context but not an independent test.
References
- Venn-Watson S et al. Efficacy of dietary odd-chain saturated fatty acid pentadecanoic acid parallels broad associated health benefits in humans: could it be essential? Scientific reports (2020). PMID 32424181
- Singh A 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). PMID 35584623
- Andreux PA 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). PMID 32694802
- Liu S et al. Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Health in Older Adults: A Randomized Clinical Trial. JAMA network open (2022). PMID 35050355
- Robinson MK et al. Pentadecanoic Acid Supplementation in Young Adults with Overweight and Obesity: A Randomized Controlled Trial. The Journal of nutrition (2024). PMID 39069269
- Chooi YC et al. Effect of an Asian-adapted Mediterranean diet and pentadecanoic acid on fatty liver disease: the TANGO randomized controlled trial. The American journal of clinical nutrition (2024). PMID 38035997
- Mercola J Molecular and cellular mechanisms of pentadecanoic acid. World journal of biological chemistry (2025). PMID 41378251
- Venn-Watson S et al. Pentadecanoic Acid (C15:0), an Essential Fatty Acid, Shares Clinically Relevant Cell-Based Activities with Leading Longevity-Enhancing Compounds. Nutrients (2023). PMID 37960259
- Weitkunat K et al. Odd-chain fatty acids as a biomarker for dietary fiber intake: a novel pathway for endogenous production from propionate. The American journal of clinical nutrition (2017). PMID 28424190
Related: Fatty15 vs NMN & NAD+ · Fatty15 Review · Fatty15 Alternatives
References
- Stephanie K Venn-Watson et al. Efficacy of dietary odd-chain saturated fatty acid pentadecanoic acid parallels broad associated health benefits in humans: could it be essential?. Scientific Reports (2020). PMID 32424181
- Ciesielski V et al. New insights on pentadecanoic acid with special focus on its controversial essentiality: A mini-review. Biochimie (2024). PMID 39395658
- Robinson MK et al. Pentadecanoic Acid Supplementation in Young Adults with Overweight and Obesity: A Randomized Controlled Trial. The Journal of nutrition (2024). PMID 39069269
- Liu S et al. Effect of Urolithin A Supplementation on Muscle Endurance and Mitochondrial Health in Older Adults: A Randomized Clinical Trial. JAMA network open (2022). PMID 35050355
- Singh A 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). PMID 35584623
- Whitfield J et al. Evaluating the Impact of Urolithin A Supplementation on Running Performance, Recovery, and Mitochondrial Biomarkers in Highly Trained Male Distance Runners. Sports medicine (Auckland, N.Z.) (2025). PMID 40839339
These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure, or prevent any disease. Content is for informational purposes only and is not medical advice; consult a qualified healthcare provider before starting any supplement. As an Amazon Associate we earn from qualifying purchases.