Retatrutide in Australia

Triple GLP-1, GIP and glucagon receptor agonist. What sets retatrutide apart is that one synthetic peptide switches on three receptors together, GLP-1, GIP and glucagon, rather than the single target of semaglutide or the two of tirzepatide. Eli Lilly is still running Phase 3 trials on it, which means no licensed medicine exists yet and the only material available is a research vial of the kind shown here.

Adiposity: endpoints covering total and visceral fat mass in the Phase 2 obesity trial. Energy expenditure: indirect-calorimetry work in preclinical models examining what the glucagon receptor adds. Glycaemic control: fasting glucose and HbA1c measured in the Phase 2 type 2 diabetes group. Cardiometabolic markers: triglycerides, blood pressure and liver-fat fraction tracked as secondary endpoints. Comparative pharmacology: modelling that pits it directly against semaglutide and tirzepatide. In the Phase 2 obesity trial (Jastreboff et al., NEJM 2023), the top-dose group lost on average as much as 24.2% of body weight by week 48, and waist measurement, blood pressure and lipids all improved too. A parallel Phase 2 study in type 2 diabetes recorded falls in HbA1c together with the weight loss. The Phase 3 TRIUMPH program is still running, and retatrutide carries no regulatory approval for any purpose.

Over 48 weeks the Phase 2 trial recorded average weight reductions of 17.5% at 4mg, 22.8% at 8mg and 24.2% at 12mg weekly, versus 2.1% for placebo, alongside smaller waist circumference and lower blood pressure, triglycerides and liver fat. Those are the trial endpoints that 'retatrutide before and after' actually points to; photographs posted on forums do not count as evidence.

Across the Phase 2 trials the events seen most often were gastrointestinal, namely nausea, diarrhoea, vomiting and constipation, mostly mild to moderate and tied to dose, with a faster heart rate and skin sensations appearing at the higher doses. More people in the top-dose groups stopped because of adverse events. Establishing long-term safety is the job of Phase 3.

In the published Retatrutide research, the amounts used were 0.5, 1.5, 3, 3/6 or 3/6/9/12 mg (top doses by stepwise escalation), Once weekly, subcutaneous in human, phase 1b, type 2 diabetes (Urva S et al. (2022)); 0.5 mg; 4 mg (start 2 mg or no escalation); 8 mg (start 2 or 4 mg); 12 mg (start 2 mg), Once weekly, injection in human, phase 2, type 2 diabetes (Rosenstock J et al. (2023)); 1 mg; 4 mg (start 2 or 4 mg); 8 mg (start 2 or 4 mg); 12 mg (start 2 mg), Once weekly, subcutaneous in human, phase 2, obesity (Jastreboff AM et al. (2023)). These are the figures each study reports for its own model, listed in full in the dosage table on this page with links to PubMed. Peptide Aus supplies Retatrutide for in-vitro research and does not give dosing guidance for people.

Where tirzepatide works on GLP-1 and GIP, retatrutide also recruits the glucagon receptor. Judged by their separate trials, retatrutide's highest dose shed more weight on average (24.2% at 48 weeks) than tirzepatide's (22.5% at 72 weeks), though the two have never been compared in one trial.

Semaglutide is a single GLP-1 receptor agonist that comes in a registered pen, whereas retatrutide is a triple agonist still under investigation. Its Phase 2 weight loss came in above the 14.9% semaglutide reached in STEP-1.

Rather than the incretin receptors, cagrilintide acts through amylin. It is tested both alone and paired with semaglutide as CagriSema, while retatrutide packs three receptor actions into a single molecule.

Not as a licensed medicine. It remains an investigational compound in Phase 3 testing that the TGA has neither received a submission for nor registered, so no pharmacy stocks it, no prescription route exists and nothing can be compounded. The only form on offer is research-grade material, and Peptide Aus carries it in two formats for laboratory work alone: lyophilised vials spanning 10mg to 60mg and retatrutide pens in 15mg, 20mg, 30mg and 70mg.

No. High-street pharmacies only carry registered medicines, and retatrutide is not registered in any country. A compounding pharmacy also has no lawful route to prepare an unapproved investigational drug for supply. The retatrutide pens listed here ship from Australian stock as research devices through Peptide Aus, and are not pharmacy products.

Choose the vial, which is lyophilised powder you reconstitute yourself, when the laboratory work calls for a particular concentration. The pen arrives ready to use: retatrutide already dissolved in 3 mL of aqueous solution inside a dial-a-dose device with 0.5 mg clicks, offered in 15mg, 20mg, 30mg and 70mg or made to a custom strength on request, with no mixing needed. Each is a research format, and a batch certificate can be sent on request.

The receptor count is the difference: semaglutide hits GLP-1 only, tirzepatide hits GLP-1 and GIP, and retatrutide brings glucagon receptor activity on top. Across the published Phase 2 results that triple profile drove bigger weight reductions than either earlier compound managed in its own studies, although no head-to-head trial has yet put them side by side.

With bacteriostatic water added slowly down the inside wall of the vial, then swirled gently. Each vial size lists its suggested volume, and the calculator converts volume to concentration.

Lyophilised: −20 °C, sealed, away from light and moisture. Reconstituted: 2–8 °C, used within 8–12 weeks, never frozen.

No country, Australia included, has granted retatrutide marketing approval; it remains an investigational drug. That means it cannot be prescribed, dispensed or compounded for human use in Australia. Peptide Aus provides research-grade retatrutide strictly for in-vitro laboratory study, and lawful use is the buyer's responsibility.

Directly from Peptide Aus, from Australian stock, in 5 vial sizes from $144.99 (10mg) to $549.99 (60mg). Prices are AUD and GST inclusive. Paid orders before 2pm AEST/AEDT dispatch the same business day, tracked.

It depends on the vial size: 10mg takes 1 mL, 15mg takes 1.5 mL, 20mg takes 2 mL, 30mg takes 3 mL, 60mg takes 3 mL. That gives 10 mg/mL, 10 mg/mL, 10 mg/mL, 10 mg/mL, 20 mg/mL respectively. The reconstitution steps on this page and the calculator cover the rest.