What's Actually in Your Supplements?
If you've spent any time on social media recently, you may have seen the discussion around supplements being independently tested and not containing the amount of active ingredient stated on the label.
While the conversation has centred around one particular brand, the wider issue isn't unique to that company. Instead, it highlights an important question that all athletes should consider:
How can you be confident that the supplements you're buying contain exactly what's written on the label?
When choosing a supplement, many people focus on the ingredients, price or recommendations from friends and social media. However, the quality of a supplement is just as important as the ingredients themselves.
How are supplements regulated in the UK?
Yes. In the UK, food supplements are regulated as foods and must comply with food law. This includes requirements around safety, labelling and the information provided to consumers. They are not regulated as medicines and cannot be marketed as treating or preventing disease.
Unlike medicines, however, food supplements are not routinely tested by an independent regulator before they are placed on the market. Instead, manufacturers are responsible for ensuring their products are safe, comply with food legislation and that the information on the label is accurate.
Many manufacturers have robust quality assurance processes and produce supplements to a very high standard. However, because products are not routinely independently tested before they reach the market, the quality and consistency of supplements can vary between manufacturers. This is one of the reasons why independent third-party testing programmes, such as Informed Sport, Informed Choice and Informed Protein, can provide an additional level of reassurance.
Why should athletes care about supplement quality?
For most people, it comes down to confidence in the product they're buying.
If a supplement contains less of the active ingredient than stated on the label, you may not receive the benefit you were expecting. For example, if you're taking creatine to support high-intensity exercise performance, but the product contains significantly less creatine than declared, it may simply not be as effective.
Quality is also important from a safety perspective.
Occasionally, supplements can become contaminated with substances that aren't listed on the label. This may occur through cross-contamination during manufacturing or poor quality control processes.
For athletes competing in drug-tested sport, this is particularly important, as even accidental consumption of a prohibited substance could result in a positive anti-doping test. While not every strongman competition is drug tested, there are well-established natural strongman pathways and other tested strength sports that follow anti-doping regulations. If you compete - or hope to compete - in these pathways, independently tested supplements can help reduce the risk of inadvertently consuming a prohibited substance.
What is third-party testing?
Third-party testing provides an additional level of reassurance by involving an independent organisation in assessing supplements, rather than relying solely on a manufacturer's own quality control processes.
Different certification programmes have different purposes. While some focus on auditing manufacturing processes and reducing the risk of contamination with substances prohibited in sport, others verify that specific nutrients, such as protein, match the amount stated on the label. Understanding these differences can help you choose the certification that's most relevant to your needs.
Informed Sport
Informed Sport is widely recognised within elite and competitive sport.
Products carrying the Informed Sport certification are manufactured in audited facilities that operate to strict quality standards, and every batch is tested for a broad range of substances prohibited in sport before it is released for sale. This helps reduce the risk of inadvertent doping caused by contaminated supplements.
While Informed Sport doesn't verify the quantity of active ingredients listed on the label, the audited manufacturing processes and batch testing provide additional confidence in the consistency and quality of certified products.
Informed Choice
Informed Choice is a quality assurance and retail monitoring programme.
Manufacturing facilities are assessed against recognised quality standards, and products undergo regular blind testing after they have been released to the market to help reduce the risk of contamination with banned substances and impurities. Unlike Informed Sport, not every batch is tested before sale.
Like Informed Sport, its focus is on manufacturing quality and reducing the risk of contamination, rather than verifying the quantity of active ingredients.
Informed Protein
Informed Protein has a different purpose.
Rather than focusing primarily on banned substances, it has been developed specifically for protein supplements. Using independent laboratory analysis alongside manufacturer assessments, it verifies that the amount of protein stated on the label matches what's in the product, while also assessing manufacturing quality and screening for common protein adulterants.
This provides additional reassurance that the protein content matches the information provided on the label.
Does every good supplement carry one of these certifications?
No.
There are many reputable manufacturers producing excellent supplements that are not part of these certification programmes.
When choosing a supplement, it's worth considering more than just the marketing on the front of the tub. Reputable companies are usually transparent about their manufacturing processes, quality assurance procedures and any independent testing they carry out. Some choose to use recognised third-party certification programmes, while others provide information about their manufacturing standards and quality assurance processes.
Independent certification provides an additional level of reassurance because the manufacturing processes and quality systems have been assessed by an external organisation, rather than relying solely on the manufacturer's own testing procedures. Depending on the programme, products may also be screened for banned substances or have aspects of their nutritional content independently verified.
If you're unsure, you can search the official Informed Sport, Informed Choice or Informed Protein databases to confirm whether a particular product is currently certified.
The bottom line
Supplements can be a valuable addition to a performance nutrition plan when they're appropriate for your training, goals and individual needs. However, choosing a supplement shouldn't just be about the ingredients listed on the label—it's also about having confidence in the quality of the product you're buying.
Understanding what different third-party certification programmes do, and don't, verify can help you make more informed decisions when choosing a supplement. Whether you're looking for reassurance around manufacturing quality, screening for prohibited substances or verification of protein content, knowing what each certification represents allows you to buy with greater confidence.
When used appropriately, supplements can play a valuable role in supporting performance, recovery and overall health. However, they work best as part of a well-planned nutrition strategy, alongside a diet that provides the energy and nutrients needed to support your training.
Want to make the most of your supplements?
Choosing a reputable supplement is an important first step, but it's also worth considering whether you're using the right supplement, at the right dose and at the right time for your training and goals.
If you'd like personalised advice on your nutrition and supplement strategy, you can learn more about the PowerThru Performance System here.
References
UK Government. Food supplements. Available at: https://www.gov.uk/government/publications/food-supplements/food-supplements (Accessed: 2 July 2026).
LGC. Informed Sport. Available at: https://sport.wetestyoutrust.com/ (Accessed: 2 July 2026).
LGC. Informed Choice. Available at: https://choice.wetestyoutrust.com/ (Accessed: 2 July 2026).
LGC. Informed Protein. Available at: https://protein.wetestyoutrust.com/ (Accessed: 2 July 2026).
