Tirzepatide and the Rise of Dual-Hormone Diabetes Drugs

Diabetes treatment is moving fast, and the newest frontier is dual and multi-hormone medicines—drugs that work on two or three gut hormone pathways at once instead of just one. The latest results, released in October and November 2026, suggest these combinations could outperform current treatments for both blood glucose control and weight loss, though none are available in Australian pharmacies yet.

The short version

• Tirzepatide (brand name Mounjaro) already works on two hormone pathways—GIP and GLP-1—and is TGA-approved in Australia for type 2 diabetes, but it is not subsidised on the PBS (Pharmaceutical Benefits Scheme), so people pay full private cost.
• A new experimental combination called EloraTZP, pairing tirzepatide with a third hormone agent (amylin), showed stronger weight loss and HbA1c (a blood test showing average blood glucose over about three months) improvements than tirzepatide alone in a mid-stage trial.
• Other multi-hormone medicines in development—retatrutide (a triple hormone agonist) and CagriSema (combining semaglutide with an amylin-based drug)—are also producing notable results in people with type 2 diabetes and obesity.
• All of these combination treatments remain investigational. None are TGA-approved or available in Australia, and gastrointestinal side effects appear more common with combination therapy.

What’s actually new

The headline development is EloraTZP, Eli Lilly’s experimental combination of tirzepatide with eloralintide, a medicine that mimics amylin (a hormone made alongside insulin that helps regulate appetite and blood glucose). In a phase 2b trial of 367 adults with overweight or obesity and type 2 diabetes, the highest-dose combination achieved an average 23.3% weight loss and a 2.9 percentage point drop in HbA1c over 48 weeks. By comparison, tirzepatide alone (at its highest approved dose) achieved 14.8% weight loss and a 2.4 point HbA1c reduction in the same study.

Lilly has indicated it plans to move a combined formulation into larger phase 3 trials later in 2026. Phase 3 trials are the larger, longer studies required before a medicine can be considered for approval by regulators like the TGA.

What the evidence shows across the field

EloraTZP isn’t the only multi-hormone contender making news:

• Retatrutide, a triple agonist acting on GIP, GLP-1 and glucagon receptors, has shown some of the largest weight-loss results reported so far in obesity trials, with newer data in people with type 2 diabetes showing meaningfully greater weight loss than semaglutide (Ozempic) at 80 weeks.
• CagriSema, which pairs semaglutide with cagrilintide (an amylin analogue), produced stronger weight loss and similar glucose improvement compared with a lower dose of tirzepatide in one trial, though it narrowly missed matching the highest tirzepatide dose in a separate obesity study.

Across all these trials, a consistent pattern emerges: adding a second or third hormone pathway tends to improve results, but it also increases the chance of gastrointestinal side effects such as nausea, vomiting or diarrhoea, and more people stop treatment because of them.

Who this affects

These developments are most relevant to adults with type 2 diabetes, particularly those also living with overweight or obesity, since most trials have focused on this group. There is currently no published data on these combination medicines for type 1 diabetes, gestational diabetes or prediabetes, so it’s too early to know how—or whether—they might apply.

Availability and cost in Australia

This is an important reality check. Tirzepatide itself is TGA-registered for type 2 diabetes and chronic weight management, but in April 2026 Eli Lilly confirmed it would not proceed with a PBS listing after the Pharmaceutical Benefits Advisory Committee (PBAC) had recommended it earlier that year. This means tirzepatide remains a private prescription only in Australia, with no government subsidy, making it a significant out-of-pocket cost for many people.

The newer combinations discussed here—EloraTZP, retatrutide and CagriSema—are not approved anywhere in the world yet, including Australia. They exist only in clinical trials. According to Diabetes Australia, people should be cautious of any product claiming to offer these treatments outside of registered trials or TGA-approved channels.

What we still don’t know

Phase 2 results are encouraging but preliminary. We don’t yet know:

• Whether benefits hold up over years, not just months
• The true rate of side effects in larger, more diverse populations
• Long-term safety, including a 2026 class-wide safety update noting a rare eye condition (non-arteritic anterior ischaemic optic neuropathy, or NAION) linked to GLP-1 based medicines, which causes sudden vision changes and requires urgent medical attention
• Final pricing and whether any of these medicines will eventually reach the Australian market or PBS

What this means for you

• If you’re currently using tirzepatide or considering it, talk to your GP or endocrinologist about current costs, since it is not PBS-subsidised.
• Don’t seek out unapproved or compounded versions of experimental drugs like EloraTZP, retatrutide or CagriSema—they are not available safely or legally outside clinical trials in Australia.
• If you notice any sudden vision changes while on a GLP-1 based medicine, seek medical attention promptly.
• Ask your credentialled diabetes educator or dietitian how current approved treatments fit into your overall management plan while you wait for new options to be properly tested and, if appropriate, approved.

A hopeful, cautious outlook

The science behind dual and multi-hormone diabetes treatments is genuinely exciting, pointing toward a future with more effective options for blood glucose and weight management. But as always, the gap between a promising trial and a medicine in your local pharmacy can take years. For now, the best step is staying informed and working closely with your healthcare team.

Want more on managing diabetes day to day? Explore our daily meal guides, low-GI recipes and practical living tips elsewhere on Diabetes Clarity.