Eli Lilly on Wednesday released results from the first head-to-head clinical trial of its experimental obesity and diabetes injection retatrutide against Novo Nordisk's Ozempic, with patients on retatrutide losing roughly twice as much weight.
Type 2 diabetes patients on the highest dose of Ozempic (2 mg) lost an average of 21 pounds over about a year and a half, while those on retatrutide lost an average of 44 pounds on the 9 mg dose and 47 pounds on the 12 mg dose over the same period. Retatrutide takers also saw steeper reductions in A1C, a key marker of blood sugar control: 2.2% versus 1.8%.
"We believe retatrutide, if approved, could shift the treatment paradigm for people living with type 2 diabetes, obesity and related cardiometabolic conditions," Kenneth Custer, president of Lilly Cardiometabolic, said in a release.
Retatrutide, which insiders call the "triple G" or "King Kong," mimics three hormones: GLP-1, GIP and glucagon, which helps break down stored fat into energy. Ozempic was the first medication of its kind, mimicking one gut hormone, while Eli Lilly's Mounjaro mimics two.
The results have not yet been peer-reviewed or published in a medical journal and were released as the company prepares to announce quarterly earnings on Thursday. Side-effect profiles were broadly similar, though slightly more retatrutide takers reported diarrhea, slightly more Ozempic takers reported constipation, and retatrutide takers had slightly higher rates of a rare sensation disorder called dysesthesia, which can cause tingling or skin-on-fire feelings.
Eli Lilly expects to submit retatrutide to the US Food and Drug Administration for approval in early 2027, and it could become available next year for conditions including obesity, obesity-related sleep apnea and knee osteoarthritis.
The unapproved drug has already attracted copycat sellers shipping powders labeled "reta" from overseas, stoking a gray market of do-it-yourself injections. Bodybuilders say it helps shred fat and reduce appetite, though there is no way for buyers to know exactly what the powders contain. In an unusual move, the company addressed the black-market hype in its release: "Retatrutide is an investigational molecule that has not been approved by FDA or any regulatory organization anywhere in the world. Anyone purporting to sell retatrutide to consumers is breaking the law."
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Average weight loss for type 2 diabetes patients over about 18 months
pounds
Results from a head-to-head clinical trial; not yet peer-reviewed or published. Source: Eli Lilly
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Analysis
Why This Matters
If approved, retatrutide could sharply increase the weight loss available from injectable medications, with results some say could rival bariatric surgery.
The drug's pre-approval black market carries real risks: people injecting unregulated powders sold online as "reta" cannot know what they are actually taking.
The results could reshape the competitive picture in the weight-loss drug market, where Ozempic was the first of a new class of medicines and Mounjaro later delivered stronger results.
Background
GLP-1 medications reduce appetite and slow digestion. Ozempic, from Novo Nordisk, was the first medication of its kind, mimicking one gut hormone, GLP-1. Eli Lilly's Mounjaro, approved later, mimics two hormones, GLP-1 and GIP, and delivers stronger results. Retatrutide mimics three: GLP-1, GIP and glucagon, which helps break down stored fat into energy. The new findings come from the first head-to-head trial of retatrutide against Ozempic, and the results have not yet been peer-reviewed or published in a medical journal.
Key Perspectives
Eli Lilly: says retatrutide, if approved, could shift the treatment paradigm for people living with type 2 diabetes, obesity and related cardiometabolic conditions, and warns that anyone purporting to sell the unapproved drug to consumers is breaking the law.
Bodybuilders using black-market "reta": say it helps shred fat and reduce appetite, with fewer side effects than other injectable weight-loss pens, though there is no way for buyers to know exactly what the powders contain.
What to Watch
Whether the trial results hold up in peer review, since they have not yet been published in a medical journal.
Eli Lilly's FDA submission, expected in early 2027, and whether the drug becomes available next year for obesity, sleep apnea and knee osteoarthritis.
Whether authorities act against overseas sellers shipping unapproved "reta" powders, which the company says are being sold illegally.
11 claims in this story checked against 1 source: 8 supported.
Show each claim
SupportedEli Lilly says retatrutide more than doubles weight loss versus Ozempic.All Content from Business Insider: “In the first head-to-head trial versus Ozempic, retatrutide takers lost roughly twice as much weight.”
Partly supportedThe summary says the first head-to-head trial shows the “triple G” injection could shift the treatment paradigm if approved.All Content from Business Insider: ““We believe retatrutide, if approved, could shift the treatment paradigm for people living with type 2 diabetes, obesity and related cardiometabolic conditions,””
SupportedLilly released results on Wednesday from the first head-to-head clinical trial of retatrutide against Ozempic.All Content from Business Insider: “On Wednesday, the pharmaceutical giant announced the results of the first clinical trial pitting Ozempic against its newest, most powerful, and yet-to-be-approved next-generation injectable medication for obesity and diabetes: retatrutide.”
SupportedIn the trial, Ozempic patients taking 2 mg lost an average of 21 pounds over about a year and a half, compared with 44 pounds on 9 mg and 47 pounds on 12 mg of retatrutide.All Content from Business Insider: “Type 2 diabetes patients on the highest dose of Ozempic (2 mg) lost an average of 21 pounds over a period of about a year and a half on the drug. Those on retatrutide lost an average of 44 pounds (9 mg) to 47 pounds (12 mg) during that same time.”
SupportedRetatrutide patients had a greater A1C reduction than Ozempic patients: 2.2% versus 1.8%.All Content from Business Insider: “Patients also saw steeper reductions in their A1C, a key marker of blood sugar control (2.2% vs 1.8%).”
SupportedKenneth Custer, president of Lilly Cardiometabolic, said retatrutide could shift the treatment paradigm if approved.All Content from Business Insider: ““We believe retatrutide, if approved, could shift the treatment paradigm for people living with type 2 diabetes, obesity and related cardiometabolic conditions,” Eli Lilly's Kenneth Custer, the president of Lilly Cardiometabolic, said in a release.”
SupportedRetatrutide is called “triple G” or “King Kong” by insiders and mimics GLP-1, GIP and glucagon.All Content from Business Insider: “Insiders are calling Eli Lilly's retatrutide the “triple G” or “King Kong” for weight loss because it mimics three hormones: GLP-1, GIP, and a third peptide hormone called glucagon”
SupportedThe results have not been peer-reviewed or published in a medical journal and were released as Lilly prepares for Thursday’s quarterly earnings announcement.All Content from Business Insider: “The clinical trial results have not yet been peer-reviewed or published in a medical journal, but were released as the company prepares to announce its quarterly earnings on Thursday.”
Partly supportedRetatrutide could become available next year for conditions including obesity, obesity-related sleep apnea and knee osteoarthritis.All Content from Business Insider: “If all goes well, it could be available sometime next year, for conditions including obesity, obesity-related sleep apnea, and knee osteoarthritis.”
Partly supportedDysesthesia is a rare sensation disorder, which can cause tingling or skin-on-fire feelings.All Content from Business Insider: “People on retatrutide also had slightly higher rates of a rare side effect called dysesthesia, triggering tingling, skin-on-fire type sensations.”
SupportedLilly said in its release that anyone purporting to sell retatrutide to consumers is breaking the law.All Content from Business Insider: ““Anyone purporting to sell retatrutide to consumers is breaking the law.””
