Eli Lilly's "Triple G" weight loss drug: A new dawn beckons?

Eli Lilly's "triple G" weight loss drug, retatrutide, shows remarkable results in mid-stage trials, achieving up to 24.2% weight loss after 48 weeks. Targeting GLP-1, GIP, and glucagon, this drug has sparked interest in the weight-loss treatment market and is now undergoing phase 3 trials to explore its safety and effectiveness for chronic weight management and obesity-related complications.

Unprecedented weight loss

In a significant development, Eli Lilly announced promising results from a mid-stage trial of its next-generation obesity drug candidate, nicknamed "triple G." The drug, known as retatrutide, demonstrated unprecedented weight loss of up to 24.2% after 48 weeks, surpassing the effectiveness of other weight loss medications, such as Wegovy and even Lilly’s own Tirzepatide.


This breakthrough has sparked renewed interest in the weight-loss treatment market, projected to reach $100 billion by the end of the decade.

Triple G: Targeting multiple hormones for amazing results

Retatrutide, a once-weekly injected drug, belongs to the incretin class and mimics the action of the GLP-1 hormone. GLP-1 helps regulate blood sugar levels, slows stomach emptying, and reduces appetite. What sets retatrutide apart is its ability to target not only GLP-1 but also another obesity-related hormone called GIP, along with the body's receptors for a third hormone, glucagon. The combination of these three targets has led Lilly to aptly nickname the drug "triple G."


Lilly's previously reported trial of Mounjaro, another obesity drug candidate targeting GLP-1 and GIP, showed a weight loss of 22.5% after 72 weeks in obese or overweight individuals. The recent 338-person study on retatrutide demonstrated its efficacy in improving blood pressure and blood sugar levels. Moreover, the drug exhibited side effects similar to other incretin-based therapies, including mild-to-moderate nausea and vomiting.

Phase 3 trials still to come

Buoyed by the promising results from the phase 2 trial, Lilly is conducting longer-duration phase 3 trials to explore the potential of retatrutide further. These trials aim to assess the drug's safety and effectiveness not only for chronic weight management but also for treating obesity-related complications like obstructive sleep apnea and knee osteoarthritis. Lilly's chief scientific and medical officer, Dan Skovronsky, expressed confidence in the drug's potential to comprehensively address obesity and its complications.

Published: 30 June 2023