Eric Helms, the co-director of the AUT Sport Research Institute New Zealand (Sprinz) and a natural bodybuilder, said these medications are already being used in the “enhanced” or untested competitive bodybuilding space.
This is particularly the case in the US, where they can be accessed through wellness clinics, as opposed to traditional GPs.
Helms said the drugs are also growing in popularity among recreational non-competitive bodybuilders who are simply trying to maintain lower body fat.
But he said their use is typically banned in drug-tested, “natural” federations without a therapeutic-use exemption.
Insulin manipulators currently feature on the International Fitness and Bodybuilding Federation Pro League New Zealand (NZIFBB) prohibited substances list when used solely for weight-loss purposes.
The NZIFBB said it conducts natural drug-tested competitions and tests athletes for a range of prohibited substances at all its events, including anabolic steroids and diuretics.
It said, to date, athletes tested at its natural competitions have consistently returned negative results.
Helms said athletes in untested divisions tend to be more willing to experiment with performance- and image-enhancing drugs.
He said these bodybuilders are sometimes taking high-dose anabolic steroids, androgens and other substances that enhance the ability to carry muscle mass and get leaner over decades.
Helms said natural competitors tend to be more risk-averse.
He said the value GLP-1 receptor agonists offer in bodybuilding is less about a shortcut to weight loss, because these athletes are typically already well-educated and meticulous about nutrition.
But he said they can make contest preparation easier, by suppressing a lot of the food noise that comes with getting as lean as possible in the cutting phase, and some people take them post-competition to have more agency over rebounded weight gain.

Helms said the argument for and against the use of these drugs is complex, with various philosophical and moral, legal and safety reasons for why certain substances should be banned – but for him, it ultimately comes down to the spirit of the sport, and equitable fair play.
He said natural bodybuilding revolves around bringing whatever cards you were dealt to the table and using discipline, knowledge, training and experience to get as far as you can.
Helms said the idea of making that process easier, to the point where it’s not a challenge, is antithetical to many and to the concept of natural bodybuilding.
He said there are also access barriers, because of cost and availability, and permitting the drugs could force athletes who might not want to take them to do so, to feel they are on a level playing field.
Helms said GLP-1 receptor agonists are incredibly helpful for the intended clinical population when used in the right way – but there should be a notable distinction between people dieting as part of a competitive physique sport and people using these medications as an adjunct for health.
Claudia O’Neill is an Auckland-based Multimedia Journalist for Newstalk ZB with an interest in science, health and geopolitics. She holds a Bachelor of Science degree from the University of Auckland and a Postgraduate Diploma in Journalism (Distinction) from Massey University. She joined NZME in 2023.

