GLP-1 (R) — Retatrutide 12mg

What it is

Retatrutide is an investigational peptide from Eli Lilly that activates three hormone receptors: GIP, GLP-1 and glucagon. It is not approved anywhere yet; Lilly plans to file with the FDA in early 2027.

What it's studied for

The GIP and GLP-1 actions reduce appetite and improve insulin response. The added glucagon action raises energy expenditure and fat burning in the liver. That third pathway is why it is studied as a step beyond dual agonists.

Research highlights

• Phase 2 trial: about 24% average body-weight reduction at 48 weeks

• TRIUMPH-2 (type 2 diabetes): about 21% reduction at 80 weeks on 12 mg, with A1C down about 1.5 points

• TRIUMPH-3 (obesity with heart disease): about 22.6% reduction at 80 weeks

• Studied for reducing liver fat

What to expect from the research

Trials reported more gastrointestinal effects than earlier GLP-1s: diarrhea in roughly a quarter to a third of participants, plus nausea and constipation. Some participants reported skin tingling (dysesthesia) and a modest heart-rate increase. Up to about 13% stopped because of side effects. Evidence level: Phase 3, not yet approved.

Handling and storage

Supplied as a lyophilized (freeze-dried) powder in a sealed vial. Store unopened vials refrigerated at 2–8 °C, away from light. A certificate of analysis (COA) is available for each batch.