"Third-Party Tested" Isn't Good Enough, Sports Dietitian Tells Supplement Brands

Michelle Arent, RD, MPH, CSCS, CISSN, director of Olympic sports performance nutrition at the University of South Carolina, opened her keynote at Outlook on Active Nutrition by establishing her credentials from both sides of the supplement conversation.

A former professional IFBB competitor and sponsored athlete with GNC and Brooks Running who ran everything from marathons to ultramarathons, Arent has spent more than 20 years in strength and conditioning and sport nutrition. In her fourth season at t South Carolina, she is directly responsible for 14 teams and more than 315 athletes, with indirect responsibility for roughly 600 athletes and 18 teams overall.

That scale, she said, is exactly why clear, repeatable communication matters. "It is a challenge to have one-on-one conversations with 300 people over and over and over again to reiterate messages so that they remember them," Arent said. "So, from a nutrition perspective, I need to make my messaging clear and concise.”

Athletes Are Marketed To, Not Trained to Evaluate

Arent framed the core problem as an information gap rather than an athlete failing. Athletes are constant targets of sophisticated marketing, she said, but rarely have the tools to evaluate it critically. "Unfortunately, what happens is people are really good at marketing, and I don't mean that in a disservice," she said. "At the same time, the consumers of that information, the athletes, don't have the information or the lens necessary to be able to look critically at the information that's coming at them to see what is scientifically accurate, what is efficacious for what they're trying to accomplish, and what is safe."

Arent was careful to distinguish her position from an anti-supplement stance. Her program runs iron testing, vitamin D testing, and bone health and concussion protocols, and she considers many supplement ingredients essential complements to a food-first approach. But before recommending or approving any product, she asks 2 questions. The first: what does the athlete actually want the product to do? "It might not be a good match for what you're looking for," she said, describing conversations that start with an athlete simply reporting that someone told them to take something.

Is "Third-Party Tested" a Real Answer?

Her second question, which she said has increasingly become her first, is whether a product is banned-substance tested. Arent said she used to ask athletes the more common industry question, "is it third-party tested," until she realized the phrase communicates far less than practitioners assume. "Third-party testing could mean anything. It could mean heavy metal testing. It could mean I asked a group of third graders if they like the color blue on the bottle," she said. "The only thing that means banned substance testing is banned substance testing. Now, banned substance testing is third-party testing, but only banned substance testing is banned substance testing."

The stakes of that distinction, she said, are significant, given NIL contracts, competitive eligibility, and reputational risk. "Do you know how much money is on the line for some of these athletes? Contracts, NIL deals, not to mention their reputation," Arent said. "Your reputation literally is all you have. Do you want to risk one of your athletes testing positive for something as a core reflection on themselves, on you, on your university, your brand? I don't. I can't live with myself."

She also emphasized that the issue extends well beyond elite competitors, pointing to a documented case in which calcium supplements were found contaminated with a testosterone derivative, with potential consequences for consumers managing unrelated health conditions.

The Gaps Testing Logos Don't Close

Even when athletes know to look for banned-substance-testing certification, Arent said meaningful gaps remain. Certification logos don't always specify whether every batch of a product was tested, she said, leaving athletes, coaches, and staff to do additional research most of them don't have time for. "If there is a logo that you put on there that says every batch of that thing is tested, that's the one that you want to use," she said. "We're winning if we know we have to look for a logo.”

Testing consistency across product formats is another blind spot, Arent pointed out. A protein powder marketed as tested might have a bar or granola counterpart from the same brand that isn't clearly tested, or that lists a protein source without disclosing where it came from. She also cited online marketplaces as a persistent counterfeit risk for budget-conscious athletes, and recommended purchasing directly from manufacturers, checking for lot numbers and expiration dates, and confirming company contact information as ways to reduce exposure.

A Call for Deeper Industry-University Partnerships

Arent closed with a direct appeal to supplement brands: build stronger, more transparent partnerships with universities, researchers, and practitioners. She raised the possibility of finished-product efficacy research conducted in partnership with university populations, and asked whether brands could help create affordable, customizable, banned-substance-tested supplement packages for athletes managing limited budgets. She also flagged a specific friction point involving team physicians who recommend supplements, such as glucosamine, for joint support that frequently aren't banned-substance tested at all.

South Carolina, she noted, has established a program that allows certain sponsor-provided product lots to be custom tested for banned substances, a capability she said remains rare among its peer institutions. "I'm hopeful that there is a time where we don't have to do that because everybody has been substance tested," Arent said. "I implore you: is there a way that we can do that?"