A new weekly injection called retatrutide has shown promising results in treating type-2 diabetes and obesity, according to a phase-3 clinical trial published in The Lancet. The study involved 930 adults with type-2 diabetes who had not previously taken diabetes medication. Over 40 weeks, participants receiving 4, 9, or 12 milligrams of retatrutide experienced significant reductions in blood sugar levels and body weight compared to those given a placebo.

Researchers found that retatrutide reduced HbA1c levels by 1.7 to 1.9 percentage points, while placebo recipients saw only a 0.8-point drop. Participants taking retatrutide lost 11.5% to 15.3% of their body weight, over four times greater than the placebo group. The drug mimics the combined effects of three gut hormones—GLP-1, GIP, and glucagon—enhancing both appetite control and energy expenditure. Improvements in cholesterol and blood pressure were also observed, though 14 participants experienced serious side effects, mostly mild to moderate digestive issues.

Experts described the findings as highly encouraging but cautioned that further trials are needed to compare retatrutide directly with existing treatments and to assess its long-term safety and nutritional impacts.