What is Urolithin A? New recovery-boosting supplement spotted at the Tour de France

While on the tech hunt at the Red Bull-Bora-Hansgrohe team hotel in Barcelona before the start of the Tour de France, shortly before I spotted Remco Evenepoel's new Shiv TT bike in the back of an open van, something else caught my eye and sent me down a rabbit hole later that evening and over the course of the days since.

I noticed an open cardboard box with a shipping label on the side detailing its original contents: Mitopure powder, softgels and gummies.

The label showed that it had been shipped from a well-known car company in the USA, to an employee of the team in Austria.

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Initially unfamiliar with Mitopure, I later learned that it is a trademarked, highly pure form of a substance called Urolithin A, manufactured by Swiss company Amazentis – part-owned by Nestlé Research Centre – and marketed under the brand name Timeline.

Notably, that Timeline brand name was handwritten on the box, too, alongside the name of another of the team's employees.

What is Urolithin A?

In short, Urolithin A is naturally occurring substance derived from pomegranates, that is claimed to speed up the clearing of damaged mitochondria, potentially improving mitochondrial function and recovery.

Cyclingnews members will perhaps recall Tim Lawson referencing it in our premium feature on supplements too:

• Ergogenic edge or empty promise: How do we know what's really inside cycling supplements

But to dig a little deeper, I spoke to David Bailey, a man whose career spans the English Institute of Sport, three years at the Nestlé Research Centre, and a trio of titles as Head of Performance at BMC Racing, Bahrain McLaren, and nowadays NSN Cycling Team.

He explained that Urolithin A is a naturally occurring byproduct produced in your gut from the breakdown of a group of polyphenols called Ellagitannins, which are found primarily in pomegranates but also in raspberries. However, only some people can produce it in meaningful amounts, depending on their gut microbiome, genetics and diet, and thus, supplementation can be beneficial to those who can't.

In Amazentis' preclinical work – using rodents – Bailey explains that they showed that it had a "potent effect on mitophagy," the process that clears out damaged mitochondria, and given that as you age your mitochondrial function declines, this could have a positive impact on slowing the effects of aging.

This was in around 2021, long after Bailey had left Nestlé, but the company consulted him on its potential application in elite cycling.

"When I joined them, I was between teams," he explained. "I had a lot of contacts, and I made connections with other teams, and a number of teams tried it.

"There would be a potential case used for it at the back end of a Grand Tour, where you're dealing with three days of mountain stages, high calorie turnover, high, high physiological stress," he continued, but later added that, "it's still a bit of an unknown."

Is it legal?

In short, yes. Mitopure is NSF Certified for Sport; something that Bailey himself made happen.

"That was the first thing I told them. I was like, 'teams will not take this on board unless you can guarantee...' Well, you can never guarantee against contamination, but you go through the batch testing process," he said.

This certification, according to the NSF Sport website, verifies that products do not contain any of 290 substances banned by major athletic organizations, the contents of the supplement actually match what is printed on the label, there are no unsafe levels of contaminants in the tested products, the product is manufactured at a facility that is GMP (Good Manufacturing Practice) Certified and audited annually or bi-annually based on grade for quality and safety by NSF.

Which teams are using it?

Red Bull-Bora-Hansgrohe denies that they have ever used Mitopure products.

"The team is not using Mitopure at the moment," the team's press officer explained when asked for comment, and later reiterated his statement by saying "the supplement you mention was neither used, nor is it currently in use."

Bailey said he understands one team from his initial round of outreach is still using it. It's not Red Bull-Bora-Hansgrohe, for clarity, but he requested that the team name be kept off-record.

Perhaps most tellingly is that Bailey confirms that his own team, NSN, isn't using it: "As a weighted marginal gain in nutrition, it's a bit of an unknown," he explained. "There's no point rolling that out until you've got your ducks lined up with fueling – carbohydrate intake – or things that are well established like caffeine, creatine, bicarbonate use. Those things are the ones that we know there's clear evidence for."

I also spoke to Sam Impey, former performance nutritionist at British Cycling, as well as the team known today as Jayco AlUla, and who is now Co-Founder and Chief Scientific Officer at Hexis, a brand that supports numerous WorldTour teams with their fuelling strategy and tracking. He explained that he's unaware of any team using it.

So, does it actually work?

Bailey calls it an unknown. Impey concurs, saying, "It's a postbiotic that might have benefits, but the evidence base in high-performing athletes is not there. We know way less about how this works and how to use it than ketones."

Clinical trials in older non-active adults showed that supplementation improves muscle strength, endurance, and biomarkers of mitochondrial health, suggesting that it may be an effective ergogenic aid in other populations, but how that then translates to elite athletes is highly speculative.

As Bailey puts it, "The guys racing the Tour de France are freaks. They have a natural adaptation – more so than you and I. We all have an ability to mitigate the oxidative damage that you get, and they will have even more, which is why they're able to do it day in, day out.

A few examples of trials exist, and two shared with me by Bailey loosely suggest potential, but neither are cut and dry.

The first, titled 'Effects of Urolithin A supplementation on performance and antioxidant status in academy soccer players during preseason: a pilot randomised controlled trial concludes that six weeks of supplementation improved aerobic endurance and some measures of jump performance in elite academy players, while preserving aspects of antioxidant status, but caveated that confidence limits were broad, and that the study "potentially support UA as a feasible and well-tolerated intervention in athletic populations," and that it warrants further research.

The second, titled 'Evaluating the Impact of Urolithin A Supplementation on Running Performance, Recovery, and Mitochondrial Biomarkers in Highly Trained Male Distance Runners' found that "Four weeks of daily UA supplementation facilitates recovery by downregulating inflammatory pathways and indirect markers of muscle damage. However, despite a reduction in rating of exertion and increased aerobic capacity, UA supplementation did not further enhance performance in highly trained male endurance athletes."

Evidence vs opportunity

Without clear evidence that Urolithin A offers a performance gain, you'd be forgiven for wondering why teams would risk giving it to high-performing athletes on the world's biggest stage.

But despite not using it for his own team's riders, Bailey presents a sound argument.

"Scientific research moves at a glacial pace. So, you know, working in sport for you know 20 years of my life, I learned that you can't really wait for them to figure it out, and you have to make a call."

That call is probably made by weighing up the known risks against the potential upsides, and when the upside is a shot at winning the Tour de France, it's likely a hard one to ignore.