Cardivo guides

Retatrutide weight loss results: what the trials found

Updated October 30, 2026 · Wellness education, not medical advice

Key takeaways

Phase 2 (2023): up to 24.2% average weight loss after 48 weeks on 12 mg.
Phase 3 TRIUMPH-1 (2026): 28.3% (about 70 lb) after 80 weeks on 12 mg, vs. 2.2% on placebo; 45% lost 30% or more.
TRIUMPH-2 in type 2 diabetes: up to 20.8% weight loss and A1C down about 1.5 points.
Results came with diet and activity counseling, gradual dose increases and medical supervision.

Retatrutide weight loss chart

Trial	Who	Length	4 mg	8–9 mg	12 mg	Placebo
Phase 2 (NEJM 2023)	Obesity/overweight, no diabetes	48 weeks	17.1%	22.8% (8 mg)	24.2%	2.1%
TRIUMPH-1 (Phase 3)	Obesity/overweight + a related condition, no diabetes	80 weeks	19.0%	25.9%	28.3%	2.2%
TRIUMPH-2 (Phase 3)	Type 2 diabetes + obesity/overweight	80 weeks	12.7%	19.1%	20.8%	4.0%

Phase 3 figures are the "efficacy estimand" reported by Eli Lilly — the result for people who stayed on treatment. Counting everyone regardless of whether they stopped, TRIUMPH-1 results were 17.6%, 23.7% and 25.0% for the three doses, versus 3.9% on placebo.

Phase 2: the results that started the buzz

Retatrutide first made headlines in June 2023, when the Phase 2 trial was published in the New England Journal of Medicine. In 338 adults with obesity or overweight, those on the 12 mg dose lost an average of 17.5% at 24 weeks and 24.2% at 48 weeks — and their weight was still falling when the study ended. Virtually everyone on 12 mg lost at least 5% of their body weight, and 26% lost 30% or more. Those numbers were larger than anything seen in a weight-loss drug trial at the time, and they are why the drug gained a following on Reddit and social media long before it was available.

TRIUMPH-1: the pivotal Phase 3 results

In May 2026, Lilly announced the results of TRIUMPH-1, its main Phase 3 obesity trial. It randomized 2,339 adults with obesity, or overweight plus a weight-related health problem, to retatrutide 4 mg, 9 mg or 12 mg once a week or placebo for 80 weeks, on top of diet and exercise advice. Average weight loss was 19.0%, 25.9% and 28.3% on the three doses — about 47, 64 and 70 pounds — compared with 2.2% on placebo. On the 12 mg dose, 45.3% of people lost at least 30% of their body weight, a level of loss previously seen mainly after bariatric surgery. In an extension, people with a starting BMI of 35 or higher who continued to 104 weeks on their highest tolerated dose reached an average loss of about 30.3% (85 lb); people switched from placebo to retatrutide lost 19.2% in that extra period. TRIUMPH-1 also included sub-studies in knee osteoarthritis pain and sleep apnea, with results expected later.

Results in type 2 diabetes

People with type 2 diabetes usually lose less weight on any weight-loss medicine than people without diabetes, and retatrutide was no exception. In TRIUMPH-2, published in The Lancet in September 2026, 1,152 adults with type 2 diabetes and obesity or overweight lost 12.7%, 19.1% and 20.8% on 4, 9 and 12 mg over 80 weeks, versus 4.0% on placebo. Those with a starting BMI of 35 or more lost 23.4% on 12 mg. A1C fell by about 1.4–1.6 percentage points, and roughly 4 in 10 people on 9 or 12 mg reached an A1C below 5.7% — the normal, non-diabetes range (see our A1C chart). Earlier Phase 2 work also showed large reductions in liver fat, with many participants' fatty liver resolving.

How doses were increased in the trials

A frequent search is "retatrutide dosage chart" or "dosing schedule". There is no approved dose — only the doses tested in research. In TRIUMPH-1, every participant started at 2 mg once a week, and the dose was increased in steps every few weeks to reach the assigned maintenance dose of 4, 9 or 12 mg. Starting low and going slowly is what kept stomach side effects manageable. These schedules were designed for closely monitored trial participants and are not instructions for self-treatment; doses used outside trials, especially from unregulated vials that people mix themselves, are a common cause of harm. See retatrutide FDA approval and availability.

Retatrutide before and after: realistic expectations

"Before and after" photos online are dramatic, but trial averages tell a more useful story. Weight loss in the trials was gradual: most came in the first year, with the curve flattening during the second. Individual results varied widely — some people lost little, others more than a third of their body weight — and people with diabetes generally lost less. A meaningful part of the loss can be muscle unless you eat enough protein and do resistance training. And as with semaglutide and tirzepatide, stopping treatment usually leads to weight regain, so these medicines are being studied as long-term treatments, not short courses. Health benefits often show up before the scale reaches its lowest point: blood pressure, blood sugar, triglycerides and liver fat typically improve within months.

What results don't show yet

We don't yet know whether retatrutide reduces heart attacks, strokes or deaths — those outcome trials are still under way. We also don't have head-to-head results against tirzepatide; comparisons across different trials are only rough guides (see retatrutide vs. tirzepatide). And long-term safety beyond two years is unknown — see retatrutide side effects.

Track what matters while you work on your weight. Whatever medicine or plan you and your doctor choose, the numbers that change first are often your resting heart rate, your blood pressure and your blood sugar. Cardivo measures heart rate and HRV from your fingertip on the iPhone camera in about 30 seconds — no Apple Watch needed — and keeps cuff blood pressure, glucose and mood in one ad-free journal, with weekly trends and a PDF you can bring to your appointments.

This guide is general wellness education based on the public sources below. It is not medical advice, diagnosis, or treatment. Cardivo is not a medical device. If you think you are having a medical emergency, call 911.

Frequently asked questions

How much weight do you lose on retatrutide?

In the Phase 3 TRIUMPH-1 trial, average weight loss after 80 weeks was 19.0% on 4 mg, 25.9% on 9 mg and 28.3% on 12 mg, compared with 2.2% on placebo.

How much weight did people lose on retatrutide in Phase 2?

On 12 mg, average weight loss was 17.5% at 24 weeks and 24.2% at 48 weeks in the Phase 2 trial published in 2023.

Does retatrutide work for people with type 2 diabetes?

Yes. In TRIUMPH-2, people with type 2 diabetes lost up to 20.8% of their weight over 80 weeks and their A1C fell by about 1.5 percentage points.

What dose of retatrutide was used in trials?

Participants started at 2 mg once weekly and increased in steps to 4, 9 or 12 mg. There is no approved dose.

Sources

Cardivo is an ad-free iPhone app that reads heart rate and HRV from your fingertip on the camera in about 30 seconds — no Apple Watch needed — and keeps blood pressure, blood sugar, and mood in one journal you can share with your doctor as a PDF. Download on the App Store.