An experimental weight loss drug, retatrutide, has demonstrated encouraging results in helping obese adults lose weight.
According to a new study published in the Annals of Internal Medicine on Jan. 6, researchers are seeing positive effects from retatrutide, a weight loss injection being developed by pharmaceutical company Eli Lilly. Retatrutide works by mimicking GLP-1, a hormone that suppresses appetite, as well as GIP, which plays a role in fat metabolism. It also consists of glucagon, which helps to manage blood sugar levels, the New York Post noted.
Source: PixelsEffect / Getty
Here’s a breakdown of the study.
Randomized controlled trials (RCTs) assessed the efficacy and safety of glucagon-like peptide-1 receptor agonists (GLP-1 RAs) and co-agonists for treating obesity in adults without diabetes. The study, conducted by researchers from McGill University, analyzed 26 studies involving 15,491 participants. It found that GLP-1-based drugs are effective for weight loss in this group.
Among the drugs studied, retatrutide produced the greatest weight loss impact, with participants shedding up to 22.1% of their initial weight after 48 weeks. Tirzepatide (a dual agonist) and semaglutide (a GLP-1 agonist) also showed significant weight loss, with reductions of 17.8% and 13.9%, respectively, after 72 and 68 weeks. The safety profiles of these drugs were generally similar, with mild gastrointestinal side effects like nausea and diarrhea being the most common.
Source: SOPA Images / Getty
When will retatrutide be available to the public?
Retatrutide has not been FDA-approved as it still requires several trials in its development process. The New York Post noted that Phase 3 trials for the drug will continue until January 2026.
In 2023, the pharmaceutical company reported positive feedback after Phase 2 testing of the drug. It found that after 24 weeks, participants with obesity or those overweight (without diabetes) who received doses of 1 mg, 4 mg, 8 mg, or 12 mg of retatrutide experienced a mean weight loss of up to 17.5% (41.2 lbs or 18.7 kg). In a secondary analysis at 48 weeks, participants lost as much as 24.2% of their starting weight (57.8 lbs or 26.2 kg).
Eli Lilly’s groundbreaking weight loss drug comes as America grapples with an obesity epidemic. According to the Centers For Disease Control and Prevention (CDC) between August 2021–August 2023, approximately 40.3% of adults in the United States were affected by obesity, showing a slight decrease from 41.9% in 2020. However, this drop is not large enough to be considered statistically significant. Black and Latino adults are disproportionately impacted by the issue, with 49.9% and 45.6% affected, respectively, according to Trust For America’s Health.
RELATED CONTENT: This ‘Slimming’ Superfood Is Being Heralded As ‘Poor Man’s Ozempic’