Australian anti-doping officials are issuing fresh warnings about the use of peptides ahead of the world’s first sports event without drug testing.

Australian swimmer James Magnussen is among athletes to compete at the inaugural Enhanced Games in Las Vegas on May 24.

Magnussen and others have been taking performance enhancing drugs in the lead-up to the Games, founded by Australian Aron D’Souza.

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Entrepreneur D’Souza has stepped away from Enhanced Games as the parent company, trading as the Enhanced Group (ENHA), launched last week on the New York Stock exchange.

The company, with a $US1.2 billion ($A1.7 billion) evaluation, is selling performance enhancements including a range of peptides which Magnussen and other athletes are taking ahead of the Games.

But Sports Integrity Australia (SIA) is delivering fresh warnings about integrity and health risks associated with taking peptides.

SIA chief executive Sarah Benson says peptides are often falsely marketed to athletes as as safe, low-risk, and aiding recovery.

“Athletes must understand that peptides are not harmless supplements,” Benson said on Wednesday.

“They are powerful substances that can have serious and long-term health consequences, and in many cases their use is clearly prohibited in sport.”

Health risks of using peptides included possible hormonal disruption, cardiovascular issues, infection and organ damage.

In a sporting sense, Benson said prohibited peptide use threatened fair competition and could irreparably damage careers and confidence in sport.

“Under Australia’s strict liability anti-doping rules, athletes are accountable for any prohibited substance in their system - no matter the source,” Benson said.

“Our concern is that the boundaries between legitimate medical treatment, medication misuse and doping become increasingly blurred.

“This includes potential unintentional doping due to the risk of contamination or mislabelling of these substances.

“Towards the 2032 Brisbane Olympics and Paralympics, it’s important that we respond to the emergence of substances such as peptides and get ahead of these threats.”