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The majority of cases were boys and more than half of them were between 13 and 15 years old.

Almost a third of the patients were even younger — between 10 and 12 years old.

Co-lead researcher Kyle Ganson says the use of legal performance-enhancing supplements such as whey protein, creatine and pre-workout mixes — as well as illegal drugs such as anabolic steroids — has been on the rise among adolescents over the last several years.

Ganson, who is an assistant professor of social work at the University of Toronto, says pediatricians saw kidney and gastrointestinal effects of the substances.

The survey included responses from 857 pediatric specialists, who reported seeing a total of 55 patients affected by performance-enhancing supplements or drugs.

The majority of those 55 patients recovered fully, but 20 of them either had ongoing health issues or their outcome was not known.

More than half of the pediatric specialists surveyed said they never screen for performance-enhancing substances in their routine practice.

More than a quarter said they have no knowledge about the substances.

Ganson said it's important for both primary health-care providers and parents to learn about the different substances adolescents are using to achieve a muscular appearance or improve their athletic performance.

He says supplements such as whey protein and creatine are easily available at the grocery store, in pharmacies and online.

Ganson said social media influencers and friends play a big role in encouraging young people to use the substances, but many also do a lot of their own research online.

"Pediatricians (and) health-care providers at large just need to have that same level of knowledge and be able to talk about these different supplements and really know about them — what the purposes of them are, how they're marketed ... to be able to kind of get on the same level as these young people," he said.

Ganson said while it might not be possible to stop all adolescents from using dietary supplements, health-care providers and parents need to ensure they're using them as safely as possible — including not taking too much — and getting the products from reputable sources.

But if an adolescent is considering using steroids or other drugs, "then of course you want to sort of intervene in a more immediate way with the right (health-care) providers to prevent any sort of potentially serious effect," he said.

The survey was conducted as part of the Canadian Paediatric Surveillance Program of the Canadian Paediatric Society.

This report by °µÍø½ûÇø was first published Aug. 27, 2025.

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