An experimental weight loss medication that targets three hunger hormones at once is showing results that far surpass current blockbuster treatments, and its maker is now expanding access to certain patients before approval. The drug, called retatrutide, helped clinical trial participants lose up to 28 percent of their body weight over 80 weeks, according to data presented in May.
Retatrutide works differently from existing options. Most approved weight loss drugs mimic one or two hormones that regulate appetite and metabolism. Retatrutide mimics three, GLP-1, GIP and glucagon, which has earned it the nickname “Triple G.” For comparison, semaglutide, sold as Ozempic and Wegovy, targets only GLP-1 and produces roughly 15 percent weight loss. Tirzepatide, sold as Mounjaro and Zepbound, targets two hormones and leads to about 20 percent weight loss. Some participants in the retatrutide trial actually withdrew because they lost weight too quickly.
The drug also showed meaningful benefits for blood sugar control. In the latest trial, retatrutide lowered A1C levels, a key diabetes marker, by up to 1.6 percent. The manufacturer, Eli Lilly, has said a primary goal is helping people with type 2 diabetes achieve both improved glucose control and significant weight loss, a combination that has historically been difficult to accomplish with a single therapy.
Expanded Access and Regulatory Questions
Eli Lilly plans to submit retatrutide for Food and Drug Administration approval in early 2027, with a market launch possible within a year after that. In the meantime, the company is broadening its compassionate use program, which allows patients with serious or life-threatening conditions to try investigational drugs outside clinical trials. This follows reports that one 79-year-old patient received the drug through the program, prompting many doctors to request access for their own patients.
Eligibility requirements remain broad. A company spokesperson said patients must have refractory obesity and a life-threatening obesity-related complication, but did not define those terms further. Doctors note that other compassionate use programs typically offer more detailed criteria. Conditions such as obstructive sleep apnea, advanced liver disease or heart failure might qualify, but the company has not confirmed which ones. Physicians must submit a request to Eli Lilly, which says it is actively reviewing applications.
Separately, the company is in dispute with the FDA over how retatrutide should be classified. Eli Lilly argues it is a biologic, which would grant 12 years of market exclusivity, while the FDA considers it a peptide, which would allow only five years. The distinction also affects whether compounding pharmacies can produce generic versions, an important issue since about 1.5 million people currently use compounded GLP-1 medications. Meanwhile, unregulated online sellers are already offering retatrutide-like products labeled for research only, and at least 14 people have been hospitalized after taking such gray market versions, according to Public Citizen.
For patients awaiting approval, the expanded compassionate use program offers a narrow but real pathway. If the FDA review proceeds smoothly, retatrutide could become available to the broader public by 2028. Researchers say the drug’s triple-action approach may represent a significant step forward in treating obesity and diabetes together, though they caution that safety data from longer-term studies will be critical before widespread use begins.