The basics
What is retatrutide?
Retatrutide is a first-in-class, investigational once-weekly injectable developed by Eli Lilly — and the most talked-about weight-loss medication in the world right now.
A triple hormone receptor agonist — nicknamed “Triple G”.
Most weight-loss medications work on a single hormone pathway. Retatrutide simultaneously activates three of the body’s key metabolic receptors — a three-pronged approach to tackling obesity at the hormonal level that no approved medication has taken before.
GLP-1
Glucagon-Like Peptide-1
Reduces appetite and slows digestion, helping you feel fuller for longer and eat less without constant hunger.
GIP
Glucose-Dependent Insulinotropic Polypeptide
Enhances insulin response and improves how the body metabolises and stores fat.
Glucagon
Glucagon receptor
Increases energy expenditure and promotes fat burning — so retatrutide does not just reduce what you eat, it increases how much you burn.
| Medication | Ingredient | Receptors |
|---|---|---|
| Ozempic / Wegovy | Semaglutide | 1 (GLP-1) |
| Mounjaro / Zepbound | Tirzepatide | 2 (GLP-1 + GIP) |
| Retatrutide | Retatrutide | 3 (GLP-1 + GIP + Glucagon) |
8 things worth knowing about retatrutide
It's more powerful than anything before it. Ozempic targets 1 receptor, Mounjaro targets 2, retatrutide targets 3 — and the results show it.
Bariatric-surgery levels of weight loss — without surgery. A 30% reduction in body weight has historically only been achievable through gastric bypass. Retatrutide is the first medication to approach this threshold.
It treats multiple conditions simultaneously. In a single weekly injection, retatrutide has shown benefits for obesity, type 2 diabetes, knee osteoarthritis, sleep apnoea and cardiovascular risk factors — all at once.
The lowest dose is still remarkable. Even the 4 mg dose produced around 19% weight loss — comparable to the highest doses of existing GLP-1 drugs — with a lower discontinuation rate than placebo.
Eli Lilly plans to file for regulatory approval in 2027, with multiple Phase 3 trials still underway across cardiovascular outcomes, chronic low back pain and liver disease (MASLD).
Over 5,800 participants have been enrolled across the TRIUMPH Phase 3 program globally.
The glucagon component is what sets it apart — it increases the body's energy expenditure rather than only suppressing appetite.
It's a once-weekly subcutaneous injection, similar to existing GLP-1 medications, making it familiar and manageable for patients.
Want the full trial data behind these facts?
Explore the Clinical TrialsStay informed
Be first to know when retatrutide reaches Australia.
Retatrutide is not yet available to the public. But when it is, you will want to be first to know. Sign up to receive:
- The latest clinical trial results and news from Eli Lilly
- Updates on TGA regulatory progress in Australia
- How and where to access retatrutide when it becomes available
- A direct link to a trusted source to learn more
