Read this first
This is plain-language harm-reduction information, not medical advice. Peptides discussed here are research compounds; most are not approved for human use. People will use them either way — we would rather they have the facts.
Retatrutide, Eli Lilly's triple agonist (GIP, GLP-1 and glucagon receptors), has now reported phase 3 results. AJMC's report on 21 May 2026 covers TRIUMPH-1, and later results from TRIUMPH-2 and TRIUMPH-3 were summarised by Drug Discovery World.
TRIUMPH-1
According to AJMC, this randomised, double-blind, placebo-controlled trial enrolled 2,339 adults with obesity, or overweight plus at least one related condition, without diabetes. At 80 weeks the 12 mg dose produced a mean loss of 70.3 lb (28.3 per cent), and 45.3 per cent of that group lost at least 30 per cent of body weight. In a longer analysis to 104 weeks, the 12 mg group averaged 85.0 lb (30.3 per cent). The 9 mg and 4 mg doses gave average losses of 25.9 per cent and 19.0 per cent.
Safety signals reported
AJMC says gastrointestinal effects dominated: nausea, diarrhoea, constipation and vomiting, more often at higher doses. Discontinuation rates rose with dose: 4.1 per cent, 6.9 per cent and 11.3 per cent for 4 mg, 9 mg and 12 mg, against 4.9 per cent on placebo.
TRIUMPH-2 and TRIUMPH-3
Drug Discovery World, summarising Lilly's results, reports weight loss at 80 weeks of 12.7, 19.1 and 20.8 per cent across three doses in people with type 2 diabetes, with A1C falling by up to 1.6 per cent on average. In people with severe obesity and cardiovascular disease, loss was up to 22.6 per cent. It also states that major adverse cardiovascular events occurred less frequently than anticipated in both retatrutide and placebo arms. Lilly said it now has the data package to support global submissions for obesity, knee osteoarthritis pain and obstructive sleep apnoea.
Why it matters to you
These numbers are exactly why retatrutide is so heavily discussed online. But the key fact is regulatory: positive trial results are not an approval. In the sources we read, Lilly is only now moving toward submissions. Retatrutide is not a licensed medicine, which is why regulators are acting against sellers. The FDA has cited it in warning letters, and the MHRA has seized unlicensed retatrutide pens (see our other news items).
- Trial doses were titrated, supervised and made by a pharmaceutical company under quality control. A grey-market vial is none of those things.
- Higher doses came with more stopping due to side effects. People self-dosing from a vial of unknown concentration can overshoot.
- The trials ran 80 weeks or more in selected volunteers. Long-term safety in the wider public is not yet known.
Retatrutide results are strong, but strong results in a trial do not make an unlicensed vial safe.
What is still unknown
Regulatory timelines, final labelling, price, and long-term safety. We did not open Lilly's own press releases (the pages timed out), so the figures above come from the AJMC and Drug Discovery World reports.
More on the drug: retatrutide; a licensed comparison is tirzepatide.
Common questions
Is retatrutide approved?
Not in the sources we read. Lilly says it now has data to support global submissions; positive trial results are not an approval.