The accelerating use of weight loss drugs globally is sparking concerns of safety, side effects and long-term use, according to The Therapeutic Goods Administration.
Medications like Ozempic and Wegovy have seen global demand surge in recent years, with prescriptions for weight management rising nearly 20 times from 2019 to 2024.
In Australia, around 2 per cent of adults, nearly half a million people, are now taking GLP-1 medications, reflecting a global rise and the growing share of the pharmaceutical market these drugs now hold.
While the promise of rapid weight loss has captured public attention, researchers warn the reality may be more complex.
Exercise and Sports scientist Katie Lyndon told 9News that GLP-1 medications could do more harm than good if the right precautions aren’t taken.
“We’ve seen a rapid emergence of GLP-1 drugs globally. Rapid weight loss can come with unintended effects, including loss of muscle mass, bone density, and other lean tissue,” she said.
“That can increase the risk of frailty, functional decline, reduced quality of life, and other long-term health impacts,”
GLP-1 medication side effects have long been a key concern for patients.
Researchers at the University of Pennsylvania analysed more than 410,000 Reddit posts from 67,000 users reportedly taking GLP-1 drugs like Ozempic and Mounjaro, finding 44 per cent mentioned at least one side effect.
Clinical data shows around 48.6 per cent of users report adverse effects, most commonly gastrointestinal issues such as nausea, vomiting, and diarrhoea.
A 2025 Harvard research release suggests these gastric symptoms are the most common, constituting up to 70 per cent of user side effects.
Mounjaro user Rachel Edwards, aged 50, said she has been using the weight loss drug for over five months and said she has experienced complications herself.
“Initially getting used to it was pretty rough. I felt sick in the stomach, had headaches, and just felt really off – I notice it most when I increase my dose, my body needs time to adjust,” she said.
“I’ve felt fatigued and nauseous. If I eat the wrong thing, I’ll vomit.
“Another negative is that your periods can be horrendous, they become irregular, or stop, and then come back really heavily – it’s something people don’t always expect.”
Despite concerns, long-term safety remains one of the biggest unknowns of the surging array of weight loss drugs. While short-term trials show significant weight loss benefits, there is limited data on consistent use over several years.
As research continues, the challenge for patients and healthcare providers will be balancing the prescriptions of GLP-1 medications with a clearer understanding of their risks and long-term effects.
