A phase 3 clinical trial published September 29 in the National Library of Medicine shows that Eli Lilly’s investigational weight-loss drug retatrutide resulted in significant weight reduction and improvements in related conditions among participants, Newsweek reported. The findings arrive as pharmaceutical companies race to expand anti-obesity treatments beyond current GLP-1 medications like Wegovy and Ozempic.
How Does Retatrutide Work Compared to Existing GLP-1 Drugs?
While popular drugs like Wegovy and Ozempic mimic the GLP-1 hormone to help people feel full and eat less, retatrutide targets three distinct hormone receptors. The drug acts on GIP and glucagon receptors in addition to GLP-1. Researchers believe that the added glucagon activity increases energy expenditure and fat burning, driving larger weight-loss figures in clinical trials. In contrast to weekly injections common for GLP-1 therapies, Eli Lilly’s trial administered retatrutide via injection, while competitors like Wegovy also offer once-daily pills following U.S. Food and Drug Administration approval late last year.
What Did Eli Lilly’s Phase 3 Trial Find Out About Dosage and Weight Loss?
The clinical trial tracked 2,339 adults with obesity who did not have diabetes over an 18-month period, including participants with knee osteoarthritis and obstructive sleep apnea. Participants were randomly assigned to receive a placebo or a 4-milligram, 9-milligram, or 12-milligram dose of retatrutide. Results showed an average body weight reduction of 3.9 percent for the placebo group, compared to 17.6 percent for the 4-milligram dose group, 23.7 percent for the 9-milligram group, and 25 percent for the highest 12-milligram dose. Participants dealing with knee pain and sleep apnea also experienced reduced pain and fewer apnea-hypopnea events. Common side effects reported during the trial were gastrointestinal in nature.
Why Are Patients Buying Unapproved Retatrutide Online?
Despite lacking federal approval, individuals are accessing unauthorized versions of retatrutide online, at convenience stores, and through certain medical professionals, according to CBS News. Eli Lilly emphasized that the drug is strictly experimental and legally available only through its clinical trials. The company warned that illicit products sold outside of official trials may contain unknown ingredients, harmful contaminants, or incorrect dosages. Reports sent to the FDA noted that two people died after allegedly taking black-market products claiming to be retatrutide, including a woman with obesity who experienced cardiac arrest in July and another individual who bought an online product in September. Neither incident was connected to Eli Lilly’s clinical trials.
When Will Retatrutide Receive FDA Approval?
Retatrutide remains experimental and has not received approval from the U.S. Food and Drug Administration or any other regulatory agency. While Eli Lilly is expected to seek regulatory approval following its positive phase 3 trials, an official release date has not been announced. In the meantime, additional clinical trials remain underway, and drugmakers such as Novo Nordisk are exploring competing treatments.
Frequently Asked Questions
What did medical experts say about using unapproved retatrutide?
Dr. Brian Wojeck, a Yale Medicine endocrinologist and assistant professor at Yale School of Medicine, strongly advised against public use of unapproved or compounded agents. He noted that such products are unstudied and associated with increased adverse events, including hospitalizations.
How many people participated in Eli Lilly’s phase 3 trial?
The study evaluated 2,339 adults with obesity who did not have diabetes over a period of 18 months. The participant pool also included individuals suffering from knee osteoarthritis and obstructive sleep apnea.
What specific deaths were linked to black-market products?
Reports sent to the FDA detailed two fatalities involving individuals who allegedly took products claiming to be retatrutide purchased outside of clinical trials. One case involved a woman with obesity who suffered a cardiac arrest in July, and the second involved a person who bought an online product in September after speaking with a nurse.
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