Retatrutide vs Survodutide
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 phase 2 it produced about 24 percent weight loss at the top dose, and in the phase 3 TRIUMPH-1 trial Lilly reported 28.3 percent at 12 mg over 80 weeks. It is investigational, made by Eli Lilly, and not FDA approved; Lilly plans to file with the FDA in the first quarter of 2027. Because it is not an approved drug, FDA says it cannot be legally compounded.
Also: BI 456906
Survodutide is an injectable dual agonist that hits both the GLP-1 and glucagon receptors, discovered by Zealand Pharma and developed by Boehringer Ingelheim. It is being tested for obesity and for fatty liver disease (MASH), and it carries an FDA Breakthrough Therapy designation for MASH. It is still investigational and not approved for any use as of October 2026, and no US filing has been publicly announced.
Key Comparison Insights
- Both peptides belong to the Weight Loss category, suggesting similar primary applications.
Detailed Comparison
| Attribute | Retatrutide | Survodutide |
|---|---|---|
| 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. | The drug works on two fronts at once. The GLP-1 receptor arm dampens appetite, slows how fast the stomach empties, and improves blood sugar handling, the same lever that semaglutide pulls. The glucagon receptor arm is the twist: glucagon signaling raises energy expenditure and pushes the liver to burn fat rather than store it. The idea, still being proven out in trials, is that adding controlled glucagon activity to GLP-1 action burns more energy and clears liver fat faster than a GLP-1 drug alone, which is why survodutide is aimed squarely at fatty liver disease. |
| Common Dosing | 4-12 mg weekly Once weekly, same day each week | Limited community data available See research protocols |
| Administration | Subcutaneous injection weekly | Subcutaneous injection weekly |
| Typical Duration | Long-term use expected | Long-term use expected |
| Best Time to Take | Morning, same day each week | Once weekly, same day each week |
Possible Side Effects May vary by individual |
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| Research Summary | The first big human evidence was the phase 2 trial by Jastreboff and colleagues (New England Journal of Medicine, 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. In a liver-fat substudy of 98 participants, liver fat dropped by about 81 to 82 percent at the 8 and 12 mg doses by week 24. Phase 3 has since read out: in TRIUMPH-1, Lilly reported mean weight loss of 19.0, 25.9 and 28.3 percent at 4, 9 and 12 mg over 80 weeks versus 2.2 percent on placebo (efficacy estimand, which assumes people stayed on the drug; analyses counting everyone randomized come out a few points lower). TRIUMPH-2 (type 2 diabetes plus obesity) reached about 20.8 percent at 12 mg, and TRIUMPH-3 (severe obesity plus heart disease) about 22.6 percent. Side effects were dominated by dose-dependent gastrointestinal issues like nausea, vomiting, and diarrhea, plus a dysesthesia (skin sensitivity) signal at the top dose. Retatrutide sold outside of trials is not an approved, quality-controlled medicine. | This is one of the more advanced incretin dual agonists, and the human data are real, not hypothetical. In a Phase 2 MASH trial published in the New England Journal of Medicine in 2024 (Sanyal et al.), 293 biopsy-confirmed patients got weekly survodutide or placebo for 48 weeks, and MASH improved without worsening fibrosis in 47% of the 2.4 mg group and 62% of the 4.8 mg group, versus 14% on placebo. A separate Phase 2 obesity study showed weight loss up to roughly 18.7% at 46 weeks in completers. In April 2026, Boehringer Ingelheim and Zealand Pharma reported that the Phase 3 SYNCHRONIZE-1 obesity trial hit its mark with about 16.6% average weight loss, and SYNCHRONIZE-MASLD showed about 12% weight loss versus 1% on placebo plus large drops in liver fat. Large Phase 3 MASH trials (LIVERAGE and LIVERAGE-Cirrhosis) are ongoing. The catch worth knowing: nausea, vomiting, and other GI side effects are common, as with the whole incretin class, and approval is not expected before 2027. |
Frequently Asked Questions: Retatrutide vs Survodutide
What is the difference between Retatrutide and Survodutide?
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 phase 2 it produced about 24 percent weight loss at the top dose, and in the phase 3 triumph-1 trial lilly reported 28.3 percent at 12 mg over 80 weeks. it is investigational, made by eli lilly, and not fda approved; lilly plans to file with the fda in the first quarter of 2027. because it is not an approved drug, fda says it cannot be legally compounded. Survodutide is a weight loss peptide that survodutide is an injectable dual agonist that hits both the glp-1 and glucagon receptors, discovered by zealand pharma and developed by boehringer ingelheim. it is being tested for obesity and for fatty liver disease (mash), and it carries an fda breakthrough therapy designation for mash. it is still investigational and not approved for any use as of october 2026, and no us filing has been publicly announced. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Retatrutide or Survodutide?
Neither is universally "better" - the choice depends on your specific goals. Retatrutide is typically used for weight loss purposes, while Survodutide is used for weight loss. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Retatrutide and Survodutide be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Retatrutide and Survodutide 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.