GLP-1 Agonists in Australia: The New Frontier in Weight Management

What Are GLP-1 Agonists?

Glucagon-like peptide-1 (GLP-1) receptor agonists represent one of the most significant advances in obesity treatment in recent decades. Originally developed for type 2 diabetes, these medications mimic a hormone naturally produced in your intestines that regulates appetite and blood sugar.

When you eat food, your body naturally releases GLP-1, which:

• Slows gastric emptying (keeps food in your stomach longer)

• Increases feelings of fullness

• Reduces appetite by acting on brain centers that control hunger

• Improves insulin secretion while reducing glucagon (a hormone that raises blood sugar)

GLP-1 receptor agonists essentially provide a higher, more sustained level of this hormone activity than what occurs naturally.

The Leading Medications in Australia

Semaglutide (Ozempic®, Wegovy®)

Semaglutide made headlines when clinical trials showed participants losing an average of 15% of their body weight over 68 weeks—far exceeding the results of previous weight loss medications.

In Australia:

• Ozempic is available on the Pharmaceutical Benefits Scheme (PBS) for type 2 diabetes, costing approximately $42.50 per month with a concession card or $130-$160 without PBS subsidy

• Wegovy (the higher-dose version specifically for weight management) was registered by the TGA in June 2023 but is not yet PBS-listed for obesity, meaning patients pay the full price of approximately $380-$430 per month

Tirzepatide (Mounjaro®)

Taking things a step further, tirzepatide is a dual GIP/GLP-1 receptor agonist that acts on two different hormone pathways.

In Australia:

• Comes in 5 doses, ranges from 2.5 mg per pen, up to 15 mg.

• Registered by the TGA in November 2023 for type 2 diabetes, with weight loss indication later added in Sept 2024

• Not yet PBS-listed, with private prescriptions costing approximately $300-$750 monthly

• Shown to produce about 20% average weight loss in clinical trials

Supply Challenges

Australia, like many other countries, has faced significant supply shortages of GLP-1 medications:

• The TGA has implemented restrictions on Ozempic prescribing to prioritise patients with diabetes

• Many pharmacies have waitlists for these medications

• The Australian Government has been working with manufacturers to increase supply

• Shortages are expected to continue into 2025 as global demand outpaces production

• Private health insurance generally does not cover prescription medications outside of hospital

What to Expect: Side Effects and Considerations

While effective, these medications aren't without side effects:

Common side effects:

• Nausea (most common, especially during dose escalation)

• Vomiting

• Diarrhea

• Constipation

• Abdominal pain

Less common but more serious concerns:

• Pancreatitis (rare)

• Gallbladder issues

• Potential thyroid C-cell tumors (seen in rodents, monitoring recommended)

Most gastrointestinal side effects improve with time as the body adjusts to the medication. Slow dose escalation helps minimize these effects.

Beyond Weight Loss: Additional Benefits

Research suggests these medications offer benefits beyond the scale:

• Reduced risk of cardiovascular events

• Improved liver health in patients with fatty liver disease

• Better joint pain in those with osteoarthritis

• Potential reduction in obstructive sleep apnea severity

• Improved quality of life metrics

The Royal Australian College of General Practitioners (RACGP) guidelines recommend:

• Comprehensive lifestyle intervention as first-line therapy

• Consideration of pharmacotherapy for those who haven't achieved sufficient weight loss through lifestyle changes

• Ongoing monitoring for efficacy and side effects

The Future of GLP-1 Agonists in Australia

The landscape is rapidly evolving:

• PBS listings for obesity management are under consideration

• Additional GLP-1 medications are in the TGA approval pipeline

• Manufacturing capacity is increasing globally

• Some of these drugs will come out of patents within few years!

Key Takeaways

GLP-1 receptor agonists represent a paradigm shift in obesity treatment, offering:

• Unprecedented efficacy outside of surgery

• Multiple health benefits beyond weight loss

• Generally manageable side effect profiles

• A medical approach that recognizes obesity as a chronic disease

While not magic bullets, these medications provide powerful tools when combined with appropriate dietary and lifestyle changes. As with any medical treatment, they should be used under physician supervision with careful monitoring of response and side effects.

Resources and Support

For people considering GLP-1 agonists:

• The Obesity Collective and the Obesity Evidence Hub

• Diabetes Australia (www.diabetesaustralia.com.au) offers resources on medication access

• PBS website (www.pbs.gov.au) provides up-to-date information on medication listings and restrictions

• The TGA website (www.tga.gov.au) posts supply shortage updates

Sources:

• Pharmaceutical Benefits Scheme (PBS). Australian Government Department of Health and Aged Care, 2024.

• Therapeutic Goods Administration (TGA). Australian Register of Therapeutic Goods, 2024.

• Royal Australian College of General Practitioners. Management of type 2 diabetes: A handbook for general practice. East Melbourne, Vic: RACGP, 2023.

• Obesity Australia. Weight Management Guidelines, 2023.

• NEJM - Semaglutide study