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

From energy products to electrolytes, ketone supplementation to beta-alanine, a significant percentage of the elite and recreational peloton are seeking a legal helping hand in supplements, often from products proclaiming maximum performance gains for a minimal outlay, which is clearly tempting. But how do you know that the trio of gels you're slurping down each hour each contain 30g of energy-boosting carbohydrate? Or that 20g of muscle-repairing goodness is nestled within a scoop of powder protein? How can you believe what's written on the tub?

A recent study found that sports supplements are used by 64% of cyclists, while research in 2024 discovered that the figure was even higher for female cyclists at 85%. Cyclingnews has looked at the ever-growing supplements industry before, notably the potentially harmful impact of ketones on the pro peloton. But here, we'll dig deep into the rules, regulations and processes that the discerning rider should look for in search of a guaranteed boost (we assure you it's more interesting than that sounds!). First: the very real issue of contamination.

Contamination concerns

According to a 2025 survey by Sport Integrity Australia, one in three sport supplements – around 35% of 200 samples – bought online contained at least one substance prohibited by the World Anti-Doping Agency (WADA) that, if detected in a urine or blood test, would result in suspension. It's not a new issue, with 2004 research by German doctor Hans Geyer discovering that 14.8% of 634 supplements purchased were contaminated with hormones, stimulants and other prohibited substances.

There are two reasons behind the contamination: accidental and intentional. It can happen when manufacturing equipment isn't cleaned to the required standards and contains remnants of ingredients from a previous product, similar to what can happen in a factory that manufactures nut products, as well as other products like cereals and breads. Insufficient cleaning can allow dust particles to permeate manufacturing areas, meaning the breads or cereals can contain traces of nuts, which can be dangerous to those with nut allergies.

There's also evidence that supplements are intentionally contaminated with 'illegal' substances to make them more effective.

And it's not just supplements. Alberto Contador famously returned an adverse analytical finding for the banned anabolic stimulant clenbuterol during the 2010 Tour de France. The amount detected was small, 50 picograms per millilitre, and Contador argued that the positive test was caused by a contaminated steak bought from a Basque supplier. The UCI, WADA and then CAS (Court of Arbitration of Sport) contested that was unlikely because Spain isn't known to have a clenbuterol meat problem, unlike China, Mexico, Guatemala and some Latin American countries where while the use of clenbuterol in livestock is banned – it's used to beef up the cows for greater yields – it persists in some black-market or illicit farming operations.

CAS ruled that while contamination of food or a supplement was possible, Contador couldn't prove the exact source, and he was banned for two years; his 2010 Tour and 2011 Giro victories were scrubbed from the record books before he returned to racing in August 2012.

More recently, there was the case of Lizzy Banks. The British athlete tested positive for two banned substances: the diuretic chlortalidone and the asthma drug formoterol. She admitted using prescribed formoterol for asthma but insisted she'd not knowingly taken chlortalidone, arguing it must have emanated from contaminated medication.

UK Anti-Doping initially accepted this explanation, issuing a rare 'No Fault or Negligence' ruling in April 2024. However, the UCI and WADA appealed, and in February 2025, the CAS overturned the decision, imposing a two-year ban backdated to May 2023 and stripping her of her results.

The case became a high-profile example of the difficulties athletes face under strict liability rules, which require proof of exactly how a substance entered the body. Banks said the ordeal cost her significant money, her career and her mental health, calling for major reforms to how contamination cases are assessed.

"Contamination is a concern; in fact, the thought of it makes me sick," says Rory Townsend, who officially moves from Q36.5 Cycling to Unibet Rose Rockets on January 1, 2026. "Call me ignorant, but I can 100% see how the Contador case happened, and it terrifies me.

"The other day I was looking at buying collagen supplements as I'm heading back to the gym [collagen supplements can potentially help muscle repair and rebuild - ed.]. I contacted one brand as I was interested in their grass-fed collagen; I asked them if they batch test their collagen. 'Occasionally,' they said, but it felt too risky, so I left it."

"Of course I'd have run it past the team before purchasing, anyway," Townsend adds. "Solo, I'll use paracetamol for pain-killing purposes, but that's it. Q36.5 really drilled into us about not taking anything from outside the team."

Townsend says he's also raced in China and avoided all meat because of contamination worries.

Batch testing and certification

Seen through WADA's lens, it's down to the athlete to prove the source of contamination. But at a team level, it's the nutrition department who are charged with ensuring products are optimum. Tim Podlogar is an exercise physiologist and performance nutritionist who juggles his academic life as a lecturer at Exeter University with consultancy work for Tudor Pro Cycling. He's previously worked with Bora-Hansgrohe. How does Podlogar ensure the likes of Julian Alaphilippe and Michael Storer consume clean supplements?

"We only use supplements from trusted, vetted suppliers," he says. "Products must be third-party tested against prohibited substances, and we only use those with batch testing and clear certification."

There are several third-party testing outfits that sports nutrition companies turn to, where their respective logos will often be plastered over the company's website and products. These include NSF Certified for Sport, Informed Choice and Informed Sport. (In fact, I'm typing this with a Beet It Sport gel beside me that features the aforementioned Informed Sport logo.)

It's not black and white, however, as while the likes of Informed Sport will test a company's products, brands can only display their logo after they formally join the certification programme. Companies pay for: pre-certification testing (initial screening for banned substances); ongoing batch testing; supply-chain risk assessment; audits and compliance checks; and, finally, licencing of their logo.

The exact cost isn't publicly listed because it depends on the number of products, batches per year, complexity of product and the risk profile of ingredients. This can run into several thousand pounds, which, says Tim Lawson of Secret Training, is why they don't currently subscribe to the full programme. Instead, their products are tested by LGC, the lab behind Informed Sport. They're then given a confidential certificate of analysis, which they can use to reassure both athletes and retailers in private.

Who can you trust?

So, procedures are in place to prevent contaminated supplement situations. But what about knowing that what's printed on the sachet is within said sachet? It's a point picked up by Podlogar.

"Batch testing for banned substances reduces the risk of contamination, but it doesn't necessarily confirm that the product actually contains the stated dose of the active ingredient," he says.

"For that reason, we prioritise companies [Tudor use MNSTRY products] with a strong track record of quality control and, where possible, certificates of analysis that confirm ingredient composition. Historically, there have been cases where athletes used supplements that were effectively placebos because they contained little or no active ingredient, so we're cautious on both doping risk and efficacy. In most teams, there is an 'approved list' system, and riders are instructed to use only products from that list."

This diligence stems from incidents like that in 2003, where the Therapeutic Goods Administration (TGA) ordered the recall of 219 vitamin and nutritional supplements after an audit of Sydney-based Pan Pharmaceuticals Ltd. The TGA accused the company of risking lives by "releasing products despite failing to test raw ingredients, fudging the results of in-house tests and failing to clean equipment between batches, potentially contaminating products". Dozens of people suffered adverse reactions, and 19 were hospitalised after taking Pan products. The company immediately went into liquidation.

In the European Union, whose rules the UK has adopted since Brexit, energy drinks, protein powders and other sports nutrition products fall under several overlapping food regulations, depending on their composition, claims and marketing. For those of you who love nothing more than digesting rules and regulations for breakfast, feel free to dip into the following, as it's all online: general food labelling and nutrition facts fall under regulation 1169/2011; nutrition and health claims, like high protein, you're talking 1924/2006; supplements 2002/46/EC… It's all designed to protect consumers, improve food safety and ensure transparency.

Seeking the source

Lawson's a stickler for quality control. It laid the foundation for the success of the first company he founded, Science in Sport, in 1992, which was acquired by Provexis PLC in 2012 for around £8 million. After Lawson left, he soon set up Secret Training. He says he doesn't tend to do independent analysis on ingredients per se. "Instead, I source them properly and pay due diligence. I'll give you an example. An email came through the other day from someone in China offering me urolithin A…"

Urolithin A is a natural metabolite produced in the gut when certain polyphenols from foods like pomegranates, berries and nuts are broken down by specific gut bacteria. It's known for activating mitophagy, the cellular process that removes damaged mitochondria (energy powerhouses in cells) and stimulates the growth of new, healthy ones.

"It's especially good for ageing athletes," Lawson adds. "And it's also potentially beneficial when you're training hard. This can damage mitochondria, so they're less productive and take up space. Studies show that when subjects first take urolithin A, their mitochondrial levels fall, but their aerobic capacity is maintained. After further use, the rebuilt, healthier mitochondria increase in number, and aerobic capacity goes up."

The most studied commercial form is Mitopure, which has undergone clinical trials. Results have been positive with good tolerability and no serious adverse effects at suggested doses, though long-term data studies are limited.

"We know it works in humans, we know the mechanism, but we don't quite know the magnitude of the effect, although I know Louise Burke and the Australian Institute of Sport are looking at this with athletes," Lawson says.

In fact, a recent study by Burke showed that four weeks of daily urolithin A supplementation helped recovery, reduced the rate of perceived exertion and increased aerobic capacity; but it didn't actually improve performance.

"Anyway, I received an email from China with someone offering me urolithin A powder," says Lawson. "I'm thinking that's cool because urolithin A's been on my radar for a while, but how do I know what's in it? If money was no object, I could put someone on it, check its composition, undertake research…"

But money is clearly a consideration, especially when these unsolicited emails stack up. You can't test every ingredient offer, every time. Instead, says Lawson, you must check there's a chain of credibility.

"Take the isomaltulose we use in our Training Mix. It's a sugar that naturally occurs in small amounts in honey. It's more resistant to digestive enzymes, so you don't experience a glucose or insulin spike. Now, I could probably get this from a broker cheaper in far-flung locations of the world. But that's no way to assure quality for the customer.

"Instead, you need a chain of credibility. BENEO, who provide ingredients we use like Palatinose, wouldn't mess around with the distributors Kreglinger Europe [with poor product] and vice versa. It's the same with a company like Cambridge Commodities, who screen its ingredients when shipping into the UK.

"Ultimately, at every stage, there needs to be a level of trust. There are many good brands. But there are also brands that haven't really got a clue what's in their product. They've just gone to a contract manufacturer who has a catalogue of white label stuff and slapped some branding on it. There are tons of those sites around, and that's why we have so many 2:1, 1:08… formulations."

Branding white label products is common, as it's not only a quick way to enter the market, but with no research and development costs, the initial outlay is low, meaning you can spend more money on marketing and influencers. A quick Google and you'll tap into potential business opportunities via the likes of Supplement Factory UK and Future Nutrition. "It's just no way to ensure correct composition and quality," says Lawson. Credibility comes from getting your hands dirty. Which Lawson, the scientist, is famed for.

Delicious data

"Our latest product is the TrueStart Energy Gel. I decided I wanted a product with real coffee in, so I played around with a few ideas. Firstly, I added a coffee bean to a gel because that adds to the coffee feel. But that just felt like you had a bit in your gel!" Lawson says.

"So, I went to the supermarket and bought some Nescafé espresso sachets. I whack it into a mini blender with a plain gel, and there's foam everywhere. It actually didn't taste too bad, but I thought, 'I have absolutely no idea what's in that powder'.

"That's when I got in contact with Simon [Hills, joint founder] of TrueStart. They're known for really nailing the caffeine content of their products, while banishing a lot of the rubbish [like mycotoxins and heavy metals]. He had folders of information on coffee beans. So they made it really easy for me to tap into the data. I can trust them."

So, when Lawson says there's 75mg of caffeine in a gel, his (and TrueStart's) due diligence means it should be 75mg.

He also stresses that just because a sports nutrition product might feature 'natural' ingredients, it doesn't necessarily mean you're consuming the benefits stated on the packet. "Reference books might say there's 30mg of vitamin C in an orange. But if you gather them up from different supermarkets, one orange might feature 60mg, one 30mg and another none at all. There are fewer guarantees with whole foods.

"I was actually talking about this with someone at AMACX. He said that one of the processes they've put in place is to ensure there's 100mg of anthocyanin in the cherry extract of their cherry juice gels. This is the active ingredient that could potentially reduce muscle damage and pain after exercise.

"They've standardised the natural situation, but I'm sure many don't. When it comes to using natural ingredients, it's similar to grapes: different years can produce good or moderate wines. So, the manufacturer must be extra careful with these and what they're claiming. You don't want a Tour de France rider climbing a mountain and thinking, 'I hope it's been a vintage year for energy gels.'"

At the other end of the spectrum, he says that ultra-processed foods don't necessarily mean bad. "The lycopene in ketchup is more bioavailable than in a tomato, for example." We'll leave that there. The pros and arguably many cons of ultra-processed food are a feature – if not a book – in itself.

Do you really need it?

The sports nutrition world has regulations in place, but there's still a Wild West element to proceedings. It's down to the consumer and WorldTour teams to do their homework. That not only applies to a product's quality control, but also whether you really need that specific ergogenic aid. Do not be blinded by marketing. Will you really race 25% faster with a squeeze of a sachet? Will that supplement really benefit you, and where you are in your cycling journey?

"Supplementation has to be individualised," says Podlogar. "Take the WorldTour level. A sprinter, time triallist and pure climber don't have identical performance demands, so it wouldn't make sense to give them all the same supplement plan. For instance, I'm not convinced we currently have strong evidence to support routine creatine use in climbers, where any increase in body mass could be problematic, but there is more justification for considering it with sprinters."

"Another example is ketone supplements," he adds. "I don't see robust evidence for a clear performance benefit in most real-world racing scenarios, and there are situations where they could be harmful to performance if used during competition. However, if an athlete feels that ketones help them with recovery, and we've checked legality and safety, I don't object to their use in that context. Ultimately, it's always a balance between evidence, practical demands of the rider's role, side-effect profile and the athlete's own preferences."

Evidence is particularly important when a 'breakthrough' study or product attracts attention. "When something new appears, we look at the totality of evidence," says Podlogar. "The number of studies, independence of research groups, characteristics of the participants (are they comparable to our riders?), and the magnitude and consistency of the effect. We also check safety data and any updates to WADA regulations or guidance from anti-doping organisations.

"If a supplement looks promising and is legal, there is the option to test it 'in-house' before rolling it out widely. That might involve small pilot trials during training camps or with development riders, where we can monitor performance, side effects and practicality without risking major races. Only if it passes those checks would it be considered for integration into race-day protocols."

All in all, the world of sports nutrition is a careful balancing act. From the keen amateur to the world's finest, it's not just about chasing the next ergogenic edge – it's about trust, evidence and, those two words again, due diligence. From batch-tested gels to rigorously certified powders, knowing what's inside the sachet is as important as knowing when to take it. Marketing claims can tempt, but you should always check the credentials, question the hype and personalise supplementation to match real-world needs. After all, it's one thing to hope for a vintage year in racing, but when it comes to energy gels, it pays to be certain.