Eli Lilly (LLY) Stock: Retatrutide Lowers Blood Sugar and Delivers 17% Weight Loss in Clinical Trial

TLDR

• Eli Lilly’s new “triple-G” medication, retatrutide, has successfully completed its initial late-stage trial for Type 2 diabetes patients.
• The drug demonstrated a reduction in blood sugar (HbA1c) by 1.7%–2% compared to a 0.8% reduction with a placebo over 40 weeks.
• Participants achieved up to a 16.8% decrease in body weight at the highest dosage.
• Retatrutide targets three hormones: GLP-1, GIP, and glucagon, whereas existing medications target one or two.
• Lilly has not yet submitted an application for FDA approval; seven more Phase 3 trial results are anticipated by the end of the year.

(SeaPRwire) –   Eli Lilly’s experimental drug, retatrutide, has met the primary objective of its first late-stage diabetes trial, effectively lowering blood sugar levels and promoting weight loss in individuals with Type 2 diabetes, the company announced on Thursday.

Eli Lilly’s experimental weight-loss drug retatrutide met the primary and key secondary endpoints in a trial, showing significant reductions in weight loss and blood sugar levels. https://t.co/OFBUzypgGt

— The Wall Street Journal (@WSJ) March 19, 2026

The 40-week study involved patients with Type 2 diabetes who were managing their condition solely through diet and exercise. Participants entered the trial with an HbA1c, a standard measure of blood sugar, ranging from 7% to 9.5%.

Eli Lilly and Company, LLY

Retatrutide resulted in an average HbA1c reduction of 1.7% to 2% across different doses, compared to a 0.8% reduction observed in the placebo group. This outcome fulfilled the trial’s primary goal.

Regarding weight loss, patients receiving the highest dose experienced an average reduction of 16.8% of their body weight, calculated among those who completed the drug treatment. When all participants were included, including those who discontinued the medication, the average weight loss was 15.3%.

For comparison, Lilly’s current drug, Zepbound, facilitated weight loss in diabetes patients ranging from 11% to 13.1% in similar 40-week trials. Retatrutide has shown greater weight loss results, although direct comparative trials between the two are not available.

Louise Chen, an analyst at Scotiabank, described the results as “the highest levels of weight loss we’ve seen from an obesity drug to date” in a patient demographic that typically faces challenges in losing weight.

Analysts at J.P. Morgan offered a more cautious perspective, noting that while the drug’s efficacy is promising, it is accompanied by a higher incidence of adverse events when compared to Lilly’s diabetes medication, Mounjaro.

How Retatrutide Works

Retatrutide is administered as a weekly injection and activates three hormone receptors: GLP-1, GIP, and glucagon, earning it the moniker “triple-G.” This is one more receptor than Zepbound (tirzepatide), which targets GLP-1 and GIP, and two more than Novo Nordisk’s Wegovy (semaglutide), which targets only GLP-1.

The mechanism is designed to simultaneously suppress appetite, regulate blood sugar, and enhance calorie expenditure by engaging all three pathways.

The most common side effects were gastrointestinal in nature. Approximately 26.5% of patients on the highest dose reported nausea, 22.8% experienced diarrhea, and 17.6% had vomiting. The rate of discontinuation due to side effects was up to 5%, which Lilly characterized as relatively low.

A small number of patients reported dysesthesia, an uncomfortable nerve sensation.

Where Lilly Stands on Approval

Lilly has not yet submitted applications for regulatory approval of retatrutide for either obesity or diabetes. The data released on Thursday represents only the second Phase 3 outcome for the drug.

The company anticipates receiving results from seven additional Phase 3 trials by the end of 2025, encompassing a variety of patient groups.

Lilly is also preparing for the launch of its oral obesity medication, orforglipron, in the second quarter of this year, pending FDA approval.

Meanwhile, Novo Nordisk is working to compete. In March 2025, Novo acquired rights to a triple-receptor drug from United Laboratories International for up to $2 billion; however, this treatment is still in its early stages of development and is years away from patient availability.

Eli Lilly stock (LLY) saw a slight decrease in premarket trading on Thursday following the release of the trial results.