Do weight loss drugs really work – and can you even get them in NZ?

Ozempic is a prescription-only medicine used to help control blood sugar levels in adults with type 2 diabetes. It has recently gained attention for its use in weight loss and the treatment of binge eating. Photo / 123RF
Weight loss drugs have risen in popularity in the recent years, but a disconnect remains between those who need the drugs and those who can afford to buy them.
Drugs like Ozempic, which isn’t available in New Zealand, were developed to treat diabetes but after clinical trials, the drugs were found to aid weight loss.
Professor Jeremy Krebs is with the University of Otago and the clinical leader of endocrinology and diabetes at the Capital and Coast District Health Board, where he leads the research group.
Speaking to Francesca Rudkin and Louise Ayrey on their NZ Herald podcast, The Little Things, he said many of these medications belong to a group of drugs called glucagon-like peptide-1 (GLP-1) agonists.
“Now, what that means is that they work in the same way as our natural hormone GLP-1, but the important difference about these medications is that they have been altered in the laboratory so that they don’t get broken down by the enzyme in our body that normally breaks down our natural GLP-1.
“And that’s very important because the GLP-1 that we all make is broken down very, very quickly by an enzyme in the body. To bypass that, the clever drug companies have altered the protein structure and made this class of medications”.
Krebs said being overweight or obese is known to increase your health risks for a number of outcomes, including diabetes, cardiovascular disease and joint problems, and the medical community has realised helping people losing weight reduces those risks.
“The difficulty has been over the last 40 or 50 years, while people have been trying to achieve that from a medical perspective, is finding a medication or a drug that is effective and is safe, and we have a legacy of weight-loss drugs that have come and gone that have either not met either of those bars. And I think why there’s so much excitement around this new class of medications is because it does really appear to seem to meet both those briefs, which is great.”
He said that by tackling obesity, these drugs could be have an enormous benefit for society.
However, the medication known as semaglutide (the official name for Ozempic) is not licensed in New Zealand for weight loss. It is for treating diabetes, alongside the drugs dulagletide and liragletide – which are licensed for managing obesity -but all these drugs are difficult to get here.
Krebs said there is also the issue that people don’t know the long-term impacts of these drugs yet, as clinical trials only go out as far as two to five years.
“And therefore we simply do not know what the implications of someone taking this medication for 10 years, 20 years, which is conceivably possible, but we don’t know that at all.”
If people do take these drugs, Krebs said they need to go into it knowing it isn’t a permanent fix, and lifestyle changes would need to be made.
“This is not a, ‘I can take it for a month, six months, fix the problem and come off them, and it’s gone away’ [drug].”
But advancements in these drugs are developing by the year, and Krebs said there are already new versions – such as tirzepatides – already going through clinical trials that are showing improved results.
“The newer classes are now up to that 25-plus percent weight loss on average in the clinical trials. And it’s not everybody, of course, but you’re getting a greater weight loss that takes you into the territory of what you see with a gastric bypass operation bariatric surgery. And so you are really then getting equivalent weight loss with a medication that we’ve never had before.
“Again, who knows what the implications of that is after five years, 10 years, 15 years. We simply don’t know. It’s crystal-ball gazing, but it does open whole other avenue of research and questions.”
Listen to the full episode of The Little Things for more about weight loss drugs, including more on how these drugs work, how they can specifically help menopausal women, and the differences between using them and bariatric surgery.
The Little Things is available on iHeartRadio, Apple Podcasts, Spotify or wherever you get your podcasts. The series is hosted by broadcaster Francesca Rudkin and health researcher Louise Ayrey.