Also called: LY3437943, UPB Reta (Triple Agonist), TRIUMPH
Retatrutide is a new weight-loss medicine that is still being tested. It is a shot given once a week. It is not for sale yet in any country. Some people try to buy fake versions online or in other places, but that is not safe.
In tests, this medicine helped people lose a lot of weight. It works by copying three natural body helpers that make you feel full, keep blood sugar steady, and burn more energy. In one study, people lost up to about a quarter of their body weight. That is more than today's similar weight-loss shots.
Doctors do not know everything about it yet because big safety studies are still going on. Fake products are being sold, and some people got very sick with liver problems from them. Wait until real doctors and safety experts say it is safe and allow it to be sold.
Benefits
The main themes across 389 research studies, in plain language.
Research indicates substantial reductions in body weight across clinical trials, with some studies reporting decreases approaching or exceeding 25% at higher doses over extended periods.
Findings point to decreased appetite and caloric intake, potentially mediated through central nervous system pathways and delayed gastric emptying.
Research highlights favorable changes in body composition, including the reduction of visceral and abdominal fat with relative preservation of lean mass.
Early research suggests roles in promoting wound healing, vascular recruitment, and tissue protection through gene regulation.
Evidence suggests reductions in knee osteoarthritis pain and improvements in physical function scores, potentially linked to weight loss.
Data indicates a significant decrease in liver fat content and biomarkers associated with metabolic liver conditions.
Preclinical and biomarker studies suggest potential anti-inflammatory actions, including the reduction of specific cytokines and modulation of immune cell activity.
Studies suggest improvements in glycemic control, including reductions in HbA1c and fasting glucose levels, as well as enhanced insulin sensitivity in Type 2 Diabetes.
Studies point to improvements in cardiometabolic risk factors, including lipid profiles (triglycerides, cholesterol) and systolic blood pressure.
Animal studies suggest potential protective effects against cerebral ischemia and support for traumatic nerve injury recovery.
Research explores effects on growth hormone secretion, telomerase activity, and other biomarkers associated with aging and cellular longevity.
Clinical findings indicate a reduction in the severity of obstructive sleep apnea and improvements in sleep-related breathing issues.
Preclinical models indicate potential anti-tumor effects, including reductions in tumor volume and overcoming chemotherapy resistance in specific cancers.
Research suggests an increase in energy expenditure and resting metabolic rate, possibly driven by thermogenic effects and fat oxidation.
Technical data emphasizes the importance of high purity, mass-spec confirmation, and proper storage to ensure research reproducibility and compound stability.
You just read the research on Retatrutide. The cheat-sheet maps the most-used peptide stacks — doses, timing, and what to check before buying — on one page.
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Safety
Adverse effects reported in the research and by community use.
Reported in research and community sources — not exhaustive. Discontinue use and consult a healthcare professional if side effects occur.
Compare research-grade suppliers with third-party COAs and published purity data. For in-vitro and laboratory research use only — not for human consumption, diagnosis, or treatment.
Evidence
Every claim above traces back to a source you can check — here are 3 of them.
Efficacy and safety of retatrutide for the treatment of obesity: a systematic review of clinical trials.
Effects of retatrutide on body composition in people with type 2 diabetes: a substudy of a phase 2, double-blind, parallel-group, placebo-controlled, randomised trial.
TRIUMPH-1: Phase 3 trial of retatrutide in adults with obesity or overweight and weight-related comorbidity
Timeline
Key moments in Retatrutide’s research and regulatory timeline — sourced and dated.
News
Dated, sourced reporting that mentions Retatrutide.
Eli Lilly's retatrutide - a first-in-class triple GLP-1/GIP/glucagon receptor agonist - delivered bariatric-surgery-level weight loss across its phase 3 TRIUMPH program in obesity and type 2 diabetes, with the 12 mg dose achieving roughly 28.7% mean weight reduction at 68 weeks and about 30.3% (~85 lb) in a pre-specified 104-week extension with no plateau. In TRANSCEND-T2D-1, retatrutide cut HbA1c by 1.7-2.0 percentage points at 40 weeks, and up to 68% of participants hit the composite of A1c <=6.5% plus >=10% weight loss. The data position retatrutide at the top of the obesity efficacy ladder, ahead of tirzepatide and semaglutide, pending regulatory filings.
On May 21, 2026, Eli Lilly reported that its triple-agonist candidate retatrutide delivered up to 28% mean weight loss among treatment completers on the 12 mg dose in the pivotal TRIUMPH-1 Phase 3 trial, which randomized roughly 2,339 people with obesity and followed them over 80 weeks. The 'triple-G' molecule — targeting GLP-1, GIP, and glucagon receptors — is positioned as a potential best-in-class challenger to semaglutide and tirzepatide. Lower-dose arms achieved about 26% (9 mg) and 19% (4 mg) mean weight loss versus 2% for placebo, and the positive topline readout was flagged as a new high-water mark for the obesity pipeline.
A June 2025 Reuters investigation details a fast-growing "gray market" in which Americans import bulk semaglutide, tirzepatide, retatrutide, and cagrilintide powders from Chinese vendors — labeled as research materials — and reconstitute them into injectable weight-loss drugs at home for roughly one-tenth of the brand-name price. Buyers coordinate on Reddit and Telegram (one group, StairwayToGray, surpassed 21,000 members), pooling money for third-party purity testing. Eli Lilly and Novo Nordisk call the practice dangerous and illicit, and 38 state attorneys general asked the FDA to intervene. One profiled user overdosed after a self-dosing miscalculation, highlighting the absence of medical oversight.
STAT reports that Novo Nordisk previously shelved a promising triple agonist targeting GLP-1, GIP, and glucagon due to safety concerns, allowing Eli Lilly to advance its own candidate, retatrutide. While Novo focused on semaglutide (Wegovy), the decision highlights a conservative corporate culture that may have cost them their lead in the obesity market as retatrutide progresses through late-stage trials.
The FDA sent warning letters to five companies for selling unapproved GLP-1 peptide products, including semaglutide, tirzepatide, and retatrutide, in interstate commerce. One company, Veronvy, was cited for misbranded oral GLP-1 products falsely claiming FDA approval. The letters target peptide vendors Xcel Peptides, Swisschems, Summit Research, and Prime Peptides. This is part of ongoing FDA enforcement against unapproved GLP-1 sales amid high demand for these drugs.
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