Mazdutide vs Retatrutide
Comprehensive side-by-side comparison of mechanisms, dosing, side effects, and research
Also: IBI362, LY3305677
Mazdutide is a GLP-1 and glucagon dual agonist, which puts it between semaglutide (GLP-1 only) and retatrutide (GLP-1, GIP and glucagon). It is built on oxyntomodulin, a natural gut hormone that hits both receptors, rather than on a GLP-1 backbone. It is furthest along in China, where it is approved for both weight management and type 2 diabetes. Western approval has not happened.
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.
Key Comparison Insights
- Both peptides belong to the Weight Loss category, suggesting similar primary applications.
Detailed Comparison
| Attribute | Mazdutide | Retatrutide |
|---|---|---|
| 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 | Two receptors, two jobs. The GLP-1 arm does the familiar work: it suppresses appetite, slows gastric emptying and improves glucose-dependent insulin release. The glucagon arm is the interesting half, because glucagon is normally thought of as the hormone that raises blood sugar. At these doses the intent is to exploit glucagon's other effects, increasing energy expenditure and pushing the liver to burn fat, while the GLP-1 arm keeps blood glucose in check and cancels out glucagon's hyperglycemic tendency. That balance is the whole design: glucagon supplies extra fat burning that GLP-1 alone cannot, and GLP-1 supplies the safety margin that makes adding glucagon viable. Reported reductions in liver fat are consistent with the glucagon component doing what it is meant to. | 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. |
| Common Dosing | 4-6 mg weekly Once weekly | 4-12 mg weekly Once weekly, same day each week |
| Administration | Subcutaneous injection, once weekly | Subcutaneous injection weekly |
| Typical Duration | Ongoing weekly use in trials, typically assessed at 24 to 48 weeks | Long-term use expected |
| Best Time to Take | Same day each week, morning preferred | Morning, same day each week |
Possible Side Effects May vary by individual |
|
|
| Research Summary | The pivotal trial is GLORY-1, published in the New England Journal of Medicine in 2025: 610 Chinese adults with overweight or obesity over 48 weeks. Mean weight reduction was 11.0 percent at 4 mg and 14.0 percent at 6 mg, alongside improvements in liver fat, blood pressure and lipids. A 9 mg dose has since been studied in phase 2 (about 12.8 percent at 24 weeks) and is in phase 3. Tolerability followed the pattern of the whole class, dominated by dose-dependent nausea, vomiting and diarrhea during titration. One caveat matters when reading these numbers: GLORY-1 enrolled a population with a mean BMI of 31.1, against roughly 38 in the Western trials of semaglutide and tirzepatide, so the percentages are not directly comparable to SURMOUNT-1 or STEP-1 results. There is no completed Western phase 3 program, so neither the FDA nor the EMA has assessed it, and meaningful head-to-head data against tirzepatide or retatrutide does not exist. | 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. |
Frequently Asked Questions: Mazdutide vs Retatrutide
What is the difference between Mazdutide and Retatrutide?
Mazdutide is a weight loss peptide that mazdutide is a glp-1 and glucagon dual agonist, which puts it between semaglutide (glp-1 only) and retatrutide (glp-1, gip and glucagon). it is built on oxyntomodulin, a natural gut hormone that hits both receptors, rather than on a glp-1 backbone. it is furthest along in china, where it is approved for both weight management and type 2 diabetes. western approval has not happened. 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. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Mazdutide or Retatrutide?
Neither is universally "better" - the choice depends on your specific goals. Mazdutide is typically used for weight loss purposes, while Retatrutide is used for weight loss. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Mazdutide and Retatrutide be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Mazdutide and Retatrutide 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.