Retatrutide vs Eloralintide
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: LY3437943, Triple G
Retatrutide is the heavy hitter of the new weight-loss drugs: a once-weekly injectable peptide that hits three receptors at once - GIP, GLP-1, and glucagon - earning it the nickname triple-G agonist. In a phase 2 trial it produced some of the largest weight loss ever recorded for a drug, up to roughly 24 percent of body weight at the top dose. It is investigational, made by Eli Lilly, and not yet FDA approved as of 2026.
Also: GSBR-1290, Structure GSBR-1290
Eloralintide (Eli Lilly code LY3841136) is an investigational, long-acting, selective amylin receptor agonist given as a once-weekly subcutaneous injection for obesity. Amylin is the satiety hormone your pancreas releases alongside insulin, and eloralintide is built to mimic it without the gut side effects that sink most appetite drugs. It is not approved anywhere yet, but it has cleared Phase 1 and a 263-person Phase 2 trial with weight loss up to roughly 20 percent, and Lilly has said it is moving into Phase 3.
Key Comparison Insights
- Both peptides belong to the Weight Loss category, suggesting similar primary applications.
Detailed Comparison
| Attribute | Retatrutide | Eloralintide |
|---|---|---|
| Category | Weight Loss | Weight Loss |
| FDA Status | Not FDA Approved | Not FDA Approved |
| Clinical Status | Pre I II III IV FDA | Pre I II III IV FDA |
| Mechanism of Action | Retatrutide combines three hormone signals into one molecule. The GLP-1 component curbs appetite and slows stomach emptying, the GIP component supports insulin response and may improve how fat tissue handles nutrients, and the added glucagon receptor activity is the novel piece: glucagon can increase energy expenditure and fat burning in the liver. The idea is that two arms cut how much you eat while the third raises how much you burn, which is why retatrutide is thought to push weight loss further than GLP-1-only drugs like semaglutide or even the dual GIP/GLP-1 agonist tirzepatide. The exact contribution of each receptor in humans is still being worked out, so consider the glucagon-driven energy-expenditure story a strong hypothesis rather than fully nailed down. | Amylin (also called IAPP) is a hormone co-secreted with insulin after you eat, and it tells your brain you are full and slows how fast your stomach empties. Eloralintide is engineered to selectively switch on the amylin receptor, which is the calcitonin receptor paired with a receptor-activity-modifying protein (RAMP), in appetite-control regions of the brainstem and hypothalamus. The result is reduced food intake and earlier satiety. The reason this class is interesting is that, unlike GLP-1 drugs such as semaglutide and tirzepatide, amylin agonists seem to drive weight loss with much less nausea and vomiting, which is what the eloralintide trials reported. Whether it preserves more lean mass than GLP-1 drugs is a real hypothesis being tested, not a settled fact. |
| Common Dosing | 4-12 mg weekly Once weekly, same day each week | 120-240mg once daily (oral) Once daily |
| Administration | Subcutaneous injection weekly | Oral tablet |
| Typical Duration | Long-term use expected | 36 weeks in Phase 2 trials |
| Best Time to Take | Morning, same day each week | - |
Possible Side Effects May vary by individual |
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| Research Summary | The key human evidence is the phase 2 trial by Jastreboff and colleagues, published in the New England Journal of Medicine in 2023, which randomized 338 adults with obesity (without type 2 diabetes) over 48 weeks. Mean weight reduction reached about 24 percent at the 12 mg dose, and weight loss had not clearly plateaued by week 48, hinting the ceiling could be even higher. Among participants with prediabetes at baseline, a large majority returned to normal blood sugar. Side effects were dominated by gastrointestinal issues like nausea, vomiting, and diarrhea, the familiar pattern for this drug class, and were mostly dose-dependent. These are genuinely strong phase 2 results, but they are phase 2: larger and longer phase 3 trials are underway to confirm safety and durability, and retatrutide sold outside of trials is not an approved, quality-controlled medicine. | This is one of the few research peptides on this site with genuinely strong, recent human data. The Phase 1 proof-of-concept study (Eli Lilly, published 2026) randomized 100 adults with obesity across five ascending dose cohorts and reported dose-proportional pharmacokinetics and least-squares mean weight reductions of 2.6 to 11.3 percent by week 12, with notably low gastrointestinal side effects (nausea 8 percent, vomiting 4 percent). In November 2025 Lilly announced topline Phase 2 results in 263 adults with obesity or overweight: at 48 weeks all dose arms beat placebo, with mean weight loss from about 9.5 percent at the lowest dose up to 20.1 percent at 9 mg, versus 0.4 percent on placebo, plus improvements in waist circumference, blood pressure, lipids, and glycemic markers. The most common adverse events were mild-to-moderate nausea and fatigue. The honest caveat: full peer-reviewed Phase 2 data and any head-to-head against tirzepatide are still pending, and there are no long-term safety or cardiovascular outcome results yet because Phase 3 is only just beginning. So the early efficacy signal is impressive, but durability and long-term safety are unproven. |
Frequently Asked Questions: Retatrutide vs Eloralintide
What is the difference between Retatrutide and Eloralintide?
Retatrutide is a weight loss peptide that retatrutide is the heavy hitter of the new weight-loss drugs: a once-weekly injectable peptide that hits three receptors at once - gip, glp-1, and glucagon - earning it the nickname triple-g agonist. in a phase 2 trial it produced some of the largest weight loss ever recorded for a drug, up to roughly 24 percent of body weight at the top dose. it is investigational, made by eli lilly, and not yet fda approved as of 2026. Eloralintide is a weight loss peptide that eloralintide (eli lilly code ly3841136) is an investigational, long-acting, selective amylin receptor agonist given as a once-weekly subcutaneous injection for obesity. amylin is the satiety hormone your pancreas releases alongside insulin, and eloralintide is built to mimic it without the gut side effects that sink most appetite drugs. it is not approved anywhere yet, but it has cleared phase 1 and a 263-person phase 2 trial with weight loss up to roughly 20 percent, and lilly has said it is moving into phase 3. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Retatrutide or Eloralintide?
Neither is universally "better" - the choice depends on your specific goals. Retatrutide is typically used for weight loss purposes, while Eloralintide is used for weight loss. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Retatrutide and Eloralintide be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Retatrutide and Eloralintide together should only be considered under medical supervision, as both compounds have their own side effect profiles and potential interactions. Research on their combined use may be limited.