Retatrutide (sometimes called "Reta" or "Reta peptide") is a newer, prescription injectable medication used for medical weight loss and metabolic health. It activates three hormone receptors simultaneously — delivering results beyond what single or dual-action medications can achieve.
Retatrutide for weight loss is still an investigational medication and is not yet approved by the FDA for routine clinical use. Much of the data comes from trials conducted by Eli Lilly and Company, published in The New England Journal of Medicine.
Retatrutide is a prescription injectable medication given as a weekly subcutaneous shot — similar to other weight-loss injections — and is meant to be used as part of a medically supervised plan.
Because it's still relatively new, access and eligibility can vary. People only receive it from a medical provider who first reviews their health history and current medications, ensuring it's an appropriate and safe option.
Retatrutide is often called a “triple agonist” because it activates three different hormone receptors that help regulate appetite, blood sugar, and metabolism: GLP-1, GIP, and glucagon.
GLP-1 is a natural “after-meal” hormone. When GLP-1 receptors are activated, the brain gets stronger fullness signals, the stomach empties more slowly (so you stay full longer), and the pancreas releases insulin in a glucose-dependent way (more support when blood sugar is higher). That combination is a big reason GLP-1 medicines tend to reduce appetite.
GIP is another incretin hormone that also supports insulin release after meals. GIP activation may improve insulin sensitivity (how well your cells respond to insulin), which can help the body handle carbs more smoothly.
Glucagon is best known for raising blood sugar. Still, it also has effects tied to higher energy use, including supporting “calorie burn at rest” through metabolic pathways in the liver and other tissues. The idea behind pairing glucagon activity with GLP-1/GIP is to boost energy expenditure while GLP-1/GIP help keep appetite and glucose control in check.
Once-Weekly Subcutaneous Injection. In studies, retatrutide for weight loss has been given as a once-weekly injection under the skin, using a dose-escalation approach to improve tolerability.
Request a ConsultationSee how retatrutide stacks up against semaglutide and tirzepatide — the leading GLP-1 medications — in terms of mechanism and average weight loss outcomes.
| Medication | Mechanism | Study Duration | Avg. Weight Loss | Notable Feature |
|---|---|---|---|---|
| Semaglutide (Wegovy) | GLP-1 agonist | 68 weeks | ~14.9% | FDA-approved; strong safety profile |
| Tirzepatide (Zepbound) | GLP-1 + GIP dual agonist | 72 weeks | 15.0–20.9% | Dual receptor; FDA-approved for obesity |
| Retatrutide (Reta) | GLP-1 + GIP + Glucagon (triple) | 48 weeks | 22.8–24.2% | Highest reported weight loss; investigational |
Our physicians perform a comprehensive health review before recommending retatrutide. Here's who typically qualifies — and who may not be eligible.
Weight loss retatrutide isn't something we hand out after a quick chat. At our retatrutide clinic, we check your heart health before prescribing — because weight-loss treatment should support your health, not introduce new risks.
A physician will monitor you with regular follow-ups. We track how you're doing, review side effects, and adjust your plan when needed. Retatrutide is not just a simple prescription; it requires professional medical care.
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