Retatrutide , an experimental drug developed by Eli Lilly, is making headlines again for its results in overweight people with type 2 diabetes. The data comes from a phase III clinical trial that has been published in The Lancet and was also presented at the annual congress of the European Association for the Study of Diabetes, held in Milan.
The study, conducted in 92 medical centers and hospitals across eight countries , including Spain, reinforces the idea that this compound could become a therapeutic option for a patient profile that typically responds less well to obesity treatments. We are referring to overweight or obese adults who also have type 2 diabetes , a common and difficult-to-manage combination.
What is retatrutide and how does it differ?
Retatrutide is a triple agonist that acts on the GIP, GLP-1, and glucagon hormone receptors. This combination distinguishes it from other weight-loss and diabetes medications that target only one or two receptors. Researchers are studying it for obesity, type 2 diabetes, and weight-related complications such as cardiovascular disease and obstructive sleep apnea.
An international essay with a Spanish accent
The trial, called TRIUMPH-2 , is a phase III, randomized, double-blind, placebo-controlled study. 2.047 people were evaluated, and 1.152 were randomly assigned to receive once-weekly subcutaneous injections of either placebo or retatrutide at doses of 4, 9, or 12 milligrams . All participants also received dietary counseling and guidelines on physical activity.
The research was conducted over 80 weeks at centers in Argentina, Australia, Brazil, India, Mexico, Romania, Spain, and the United States. This international scope helps to ensure that the results are more representative, although the authors themselves point out that this is still an investigational drug and not yet available in pharmacies.
Results on body weight
In week 80, the average weight loss was 11,9% with 4 milligrams , 16,8% with 9 milligrams, and 18,8% with 12 milligrams. In the placebo group, the average weight loss was 5,1%. According to the researchers, these figures represent a significant and sustained reduction in a population that typically loses less weight with other treatments.
The data also indicate that more than half of the participants no longer met the obesity criteria, and that around 20% average reduction was achieved with the 12-milligram dose in overweight or obese individuals with type 2 diabetes. Even so, experts insist that these results should be interpreted within a clinical trial and under medical supervision.
Improvements in glucose and cardiometabolic risk
Regarding diabetes control, glycated hemoglobin (A1c) decreased by an average of 1,38% with 4 milligrams , 1,50% with 9 milligrams, and 1,45% with 12 milligrams. In the placebo group, the decrease was 0,45%. A1c reflects glucose control over the past two to three months, so these differences are considered clinically significant.
The treatment was also associated with improvements in cardiometabolic risk factors, such as blood pressure and lipid profiles , and a reduction in high-sensitivity C-reactive protein, a marker of inflammation. The most frequently reported adverse effects were gastrointestinal , which is common with this class of medications.
What the researchers say
Juan P. FrÃas, medical director and principal investigator at the Metabolic Research Institute in Los Angeles, points out that most people with type 2 diabetes are also obese, and treating both conditions simultaneously has always been a clinical challenge . In the TRIUMPH-2 study, retatrutide substantially reduced both weight and blood sugar levels, and up to 40% of participants achieved A1c levels within the normal range.
Another point highlighted by the researchers is that the drug showed an effect even at the lowest dose studied, 4 milligrams . This could facilitate personalized treatment and better adjust the intensity for each patient, although long-term safety and real-world clinical outcomes will still need to be analyzed.
A treatment that is not yet authorized
It is important to remember that retatrutide is not commercially authorized and is still considered an investigational drug . It should not be confused with an already approved product nor purchased through unregulated channels, as there is a health alert regarding unauthorized weight-loss injections , since there are no guarantees about their composition, quality, or safety. Health authorities insist that its use should be limited to authorized clinical trials.
The results of the TRIUMPH-2 trial position retatrutide as one of the most promising treatments for obesity in people with type 2 diabetes, with weight losses of up to 18,8% and clear improvements in glucose levels and cardiometabolic risk. However, it is still an experimental drug, pending approval, and its future will depend on further evaluations of its long-term efficacy, tolerability, and safety. Spain's participation and the presentation in Milan reinforce European interest in these data, which, for now, should be interpreted with caution and scientific rigor.