WHAT EACH STUDY FOUND
Retatrutide results included weight, liver, and sugar changes.
Two Phase 2 studies followed people with obesity or diabetes. A Phase 2 liver study checked fatty liver disease.
Retatrutide results come from short studies
Less hunger may appear before the scale moves. In a 48-week Phase 2 study, the top retatrutide dose brought a 24.2% average weight fall. This stage is an early test of benefit and harm. A smaller liver study found an 82.4% liver-fat fall at 24 weeks. Most people in that group reached a normal amount.
Doctors watched these people and knew each dose. The findings aren't sales claims or forecasts. Retatrutide isn't approved. The studies show what happened during set times. They can't tell you what happens years later.
The Retatrutide effects page names side effects and missing facts.
For you, an average isn't a forecast.
Phase 2 retatrutide study found more loss at larger amounts
Researchers followed 338 adults in Phase 2. This stage gives an early test of benefit and harm. Each person's weight was high for his or her height. The measure was at least 30. Some measured from 27 to under 30. They also had a health issue tied to weight. Groups got 1, 4, 8, or 12 mg each week. One group got placebo, a shot without retatrutide. The study ran 48 weeks [1].
Average body-weight change at 48 weeks:
- Placebo: -2.1%
- 1 mg: -8.7%
- 4 mg: -17.3%
- 8 mg: -22.8%
- 12 mg: -24.2%
Each larger amount brought a larger average fall. The average loss was larger in every retatrutide group.
A 2025 review covered 26 studies and 15,491 adults without diabetes. It found a 22.1% change with retatrutide 12 mg at 48 weeks. Its math gave a 95% likely range of 19.3%-24.9%. Tirzepatide 15 mg reached 17.8%. Semaglutide 2.4 mg reached 13.9% [9]. The drugs weren't tested face to face. These figures can't prove a winner.
Another 2025 review warned about weight regain after similar drugs stop. Retatrutide has no published result after stopping [10].
Your starting weight and health may change the result.
Retatrutide produced a large liver-fat drop
The liver study followed ninety-eight people who had excess weight and fatty liver disease. A scan showed at least 10% liver fat. None had type 2 diabetes. The study ran 48 weeks [5].
Liver-fat change at 24 weeks:
- Placebo: +0.3%
- 1 mg: -42.9%
- 4 mg: -57.0%
- 8 mg: -81.4%
- 12 mg: -82.4%
With 12 mg, 86% reached a normal amount below 5%. By 48 weeks, the fall was 86.0%.
A 2024 review allowed for the placebo result. It found an 81% fall for retatrutide. Semaglutide had 41%. Tirzepatide had 47% [7].
Another review covered 25 studies and 2,600 people. At week 24, the 12 mg result was still the largest. Three blood tests tied to liver strain also fell [8].
A 2025 study in mice found less liver fat and swelling [13]. The mice had a fast form of fatty liver disease. A mouse finding can't predict what happens in a person.
Read how does retatrutide work for the hormone tied to liver fat.
Your doctor can compare your liver scan with these findings.
Phase 2 retatrutide results in type 2 diabetes
In Phase 2, researchers followed 281 adults with type 2 diabetes. It was another Phase 2 test of benefit and harm. Weekly amounts rose from 0.5 to 12 mg. The study ran 36 weeks [2].
Main findings with 12 mg:
- The long-term sugar reading fell 2.02% at 24 weeks. Placebo fell 0.01%.
- Body weight fell 16.94% at 36 weeks. Placebo fell 3.00%.
- No one had a grave blood-sugar drop. No one died.
A 2026 review found sugar drops up to 2.16%. Weight fell as much as 26.56% in the groups studied [12]. Another 2026 review found possible liver help in people with diabetes [15].
Your other diabetes drugs may change the risk.
The first retatrutide study was short
The first small study followed 72 adults with type 2 diabetes. Their long-term sugar readings ran from 7.0-10.5%. Each received a shot beneath the skin every week. The study used 0.5, 1.5, 3, 3/6, and 3/6/9/12 mg. The slashes mark planned increases, not mixed amounts. The study ran 12 weeks [4].
Retatrutide remained in blood about 6 days. Over 12 weeks, the top group lost 8.96 kg more than placebo. The math gave researchers 90% confidence that the finding wasn't a fluke. The 3 mg group also had lower daily blood sugar. Side effects arose in 63%. Most were mild stomach or bowel problems.
An added part binds the drug to a blood protein. That bond slows its exit from the body.
You don't need blood-level math to see the short follow-up.
Reviews compare separate retatrutide studies with other drugs
Reviews from 2024-2025 compared results from separate studies. They help doctors see broad differences. They can't prove that one drug beats another.
Weight in adults without diabetes. A 2025 review covered 26 studies and 15,491 people. Retatrutide 12 mg had a 22.1% result at 48 weeks. The paper gave a 95% likely range of 19.3%-24.9% [9]. The papers differed too much for one fair test.
Liver fat. A 2025 review allowed for placebo. It found an 81% retatrutide drop. Semaglutide had 41%. Tirzepatide had 47% [7]. Another review covered 25 studies. Across those people, liver fat fell 5.21% overall. Retatrutide had the largest single-drug change [8].
Weight overall. A 2025 review found loss up to 24%. It said the hormone tied to liver fat may help explain the large loss [6]. That hormone can make the body spend more stored energy.
No finished study has tested these drugs together. Retatrutide studies are still running. The other drugs have longer safety records.
Use reviews to form questions for your doctor.