Quick Answer
The retatrutide results so far are strong. In the Phase 2 obesity trial published in NEJM, the 12 mg group reached 24.2% mean weight reduction at 48 weeks, compared with 2.1% for placebo. In TRIUMPH-4, Lilly later reported 28.7% mean weight reduction at 68 weeks in adults with obesity or overweight and knee osteoarthritis.
The type 2 diabetes data are also important. In TRANSCEND-T2D-1, Lilly reported average A1C reductions of 1.7% to 2.0% across retatrutide doses at 40 weeks, along with weight reductions up to 16.8%. Retatrutide remains investigational, but the clinical program has moved from promising Phase 2 data into meaningful Phase 3 readouts.
Explore the AminoRank retatrutide profileReview linked studies, category details, and vendor availability for retatrutide.View retatrutide profileResults At A Glance
Retatrutide has now produced public results across obesity, type 2 diabetes, and obesity-related complication research. The easiest way to read the story is to separate the study population from the endpoint.
| Study or update | Population | Main result reported |
|---|---|---|
| Phase 2 obesity trial | Adults with obesity or overweight without diabetes | Up to 24.2% mean weight loss at 48 weeks. |
| TRIUMPH-4 Phase 3 | Adults with obesity or overweight and knee osteoarthritis | 28.7% mean weight loss at 68 weeks on 12 mg. |
| TRANSCEND-T2D-1 Phase 3 | Adults with type 2 diabetes | A1C reductions of 1.7% to 2.0% and weight loss up to 16.8% at 40 weeks. |
| Phase 2 metabolic markers | Obesity research population | Improvements reported in several cardiometabolic measures. |
That is why retatrutide results get so much attention. The compound is not interesting because of one isolated number. It is interesting because the same triple-agonist design has shown weight, glycemic, and metabolic effects across different trial settings.
The strongest part of the evidence story is consistency. Weight loss is the headline, but the program is also producing signals in A1C, cardiometabolic markers, and functional outcomes. That makes retatrutide feel less like a narrow appetite drug and more like a serious metabolic platform.
Phase 2 Obesity Results
The Phase 2 obesity study is the foundation for most retatrutide discussion. It enrolled adults with obesity or overweight and at least one weight-related condition, but without type 2 diabetes. Participants received once-weekly retatrutide or placebo for 48 weeks.
The dose response was the key signal. Higher retatrutide doses produced larger average weight reductions, with the 12 mg group reaching 24.2% mean weight loss at 48 weeks. Lilly also reported improvements in markers such as blood pressure, lipids, glucose, and insulin.
That result helped establish retatrutide as more than a routine incretin follow-on. It suggested that adding glucagon receptor activity to GIP and GLP-1 agonism could produce a larger metabolic effect than single-pathway drugs.
Phase 3 Weight-Loss Results
TRIUMPH-4 was a major milestone because it moved retatrutide into later-stage evidence. Lilly reported that adults with obesity or overweight and knee osteoarthritis lost an average of 28.7% of body weight at 68 weeks on retatrutide 12 mg.
That study matters for two reasons. First, the weight-loss number was larger than the Phase 2 48-week result, though the trial population and duration were different. Second, TRIUMPH-4 tied weight loss to knee osteoarthritis pain and function, which makes the outcome more clinically meaningful than body weight alone.
That second point is easy to understate. People do not care about weight change only because it changes a number on a chart. They care because weight can affect pain, movement, sleep, cardiometabolic risk, and daily function. A trial that links weight reduction with knee pain and function gives the retatrutide story a more practical human dimension.
For readers comparing retatrutide results, the important point is not to collapse every trial into one ranking table. A 48-week Phase 2 obesity study, a 68-week knee osteoarthritis study, and a type 2 diabetes trial answer related but different questions.
Type 2 Diabetes Results
TRANSCEND-T2D-1 added another layer to the retatrutide story. Lilly reported that retatrutide lowered A1C by an average of 1.7% to 2.0% across doses at 40 weeks from a baseline of 7.9%. The 12 mg group also lost an average of 36.6 pounds, or 16.8%, from baseline.
Those findings matter because weight loss can be harder to achieve in type 2 diabetes populations than in obesity trials without diabetes. A compound that moves both A1C and body weight is more interesting than one that only changes appetite.
The strongest interpretation is straightforward: retatrutide is being developed as a broad metabolic compound, not just a weight-loss headline.
Tolerability In The Results
The side-effect pattern reported so far fits the incretin category. Gastrointestinal events such as nausea, diarrhea, vomiting, and constipation are the most common discussion points, especially during dose escalation.
That does not erase the strength of the results, but it does shape how they should be read. Weight-loss and A1C outcomes only matter if tolerability, discontinuation, and long-term safety remain acceptable in larger studies. That is one reason Phase 3 data are so important.
For a deeper breakdown, see retatrutide side effects and is retatrutide safe.
What The Results Mean
Retatrutide results are best understood as a clinical-development story with strong momentum. Phase 2 showed the triple-agonist concept could produce large weight reductions. TRIUMPH-4 showed a large Phase 3 result in an obesity-related complication population. TRANSCEND-T2D-1 showed meaningful glycemic and weight effects in type 2 diabetes.
That is a compelling evidence base, but it is still an investigational evidence base. Approval, labeling, real-world use, long-term outcomes, and broader safety data depend on the full clinical program.
Compare retatrutide research vendorsBrowse vendors by COAs, reviews, discounts, shipping, and payment options.View retatrutide vendorsWhat To Watch Next
The next useful updates are additional Phase 3 readouts, peer-reviewed publications from completed Phase 3 trials, longer-term safety data, and official regulatory submissions. Those are the pieces that will determine how retatrutide is ultimately positioned.
For now, the results support a positive but precise view: retatrutide has produced some of the strongest public metabolic data in the incretin field, and the remaining question is how well those results hold across the rest of the program.
FAQ
What are the best retatrutide results so far?
The strongest public results are 24.2% mean weight loss at 48 weeks in Phase 2 obesity research, 28.7% mean weight loss at 68 weeks in TRIUMPH-4, and A1C reductions up to 2.0% in TRANSCEND-T2D-1.
Are retatrutide results better than semaglutide or tirzepatide?
Retatrutide has reported very strong results, but cross-trial comparisons are imperfect because study populations, durations, endpoints, and designs differ. Dedicated head-to-head trials are the cleanest way to compare compounds.
Did retatrutide results include people with type 2 diabetes?
Yes. Lilly has reported type 2 diabetes results from TRANSCEND-T2D-1, including A1C and weight reductions at 40 weeks.
Is retatrutide available because of these results?
Retatrutide remains investigational. Research vendor listings are separate from approved prescription availability.