Mazdutide vs Petrelintide
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: ZP8396
Petrelintide is a long-acting amylin analog from Zealand Pharma, co-developed with Roche, designed as a once-weekly injection for obesity. The pitch is gentler weight loss than GLP-1 drugs but with far less nausea and vomiting. Two phase 2 trials read out positively in 2026 (up to 10.7% weight loss at 42 weeks), and a roughly 7,000-person phase 3 program has started. It is not approved anywhere.
Key Comparison Insights
- Both peptides belong to the Weight Loss category, suggesting similar primary applications.
Detailed Comparison
| Attribute | Mazdutide | Petrelintide |
|---|---|---|
| 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. | Amylin is a hormone your pancreas releases alongside insulin after meals. It acts on the brainstem to make you feel full sooner, slows stomach emptying, and curbs glucagon after eating. Zealand says amylin signaling also helps restore sensitivity to leptin, the body's long-term fullness signal. Native amylin is unusable as a drug because it clumps into fibrils and lasts minutes, so petrelintide was engineered to stay stable at neutral pH, avoid fibril formation, and last a week. That stability also means it can be co-formulated with other peptides, which is why Roche plans to combine it with its own GLP-1/GIP drug. The theory is that amylin gives more of a natural fullness feeling than GLP-1 drugs do, with fewer GI side effects; the tolerability part looks real so far, the bigger-picture claims still need phase 3. |
| Common Dosing | 4-6 mg weekly Once weekly | Not publicly disclosed (once-weekly trial doses) Once weekly |
| Administration | Subcutaneous injection, once weekly | Subcutaneous injection once weekly |
| Typical Duration | Ongoing weekly use in trials, typically assessed at 24 to 48 weeks | 16 weeks (phase 1b) to 42 weeks (phase 2) in completed trials |
| Best Time to Take | Same day each week, morning preferred | Same day each week |
Possible Side Effects May vary by individual |
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| 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. | A 16-week phase 1b trial (48 people) reported up to 8.6% mean weight loss at the highest dose versus 1.7% on placebo, with no early plateau. The phase 2 ZUPREME-1 trial (493 people with obesity or overweight, mean BMI 37) reported in March 2026 up to 10.7% mean weight loss at 42 weeks versus 1.7% on placebo. That is clearly less than semaglutide or tirzepatide produce, but tolerability stood out: no vomiting at the maximally effective dose, and side-effect dropouts (4.8%) no higher than placebo (4.9%). ZUPREME-2 (220 people with obesity and type 2 diabetes) reported in October 2026: 7.4-9.2% weight loss at 28 weeks versus 2.0% on placebo, placebo-adjusted HbA1c drops of 0.61-0.88 points, and GI dropouts of 1.9% versus 1.7%. Roche and Zealand have started phase 3a (ZUPREME-3, -4 and -5, about 7,000 people in total, including a cardiovascular-disease population). Honest take: a well-tolerated, moderate-strength drug whose real value may be as a combination partner, and the full peer-reviewed phase 2 data are still pending. |
Frequently Asked Questions: Mazdutide vs Petrelintide
What is the difference between Mazdutide and Petrelintide?
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. Petrelintide is a weight loss peptide that petrelintide is a long-acting amylin analog from zealand pharma, co-developed with roche, designed as a once-weekly injection for obesity. the pitch is gentler weight loss than glp-1 drugs but with far less nausea and vomiting. two phase 2 trials read out positively in 2026 (up to 10.7% weight loss at 42 weeks), and a roughly 7,000-person phase 3 program has started. it is not approved anywhere. The main differences lie in their mechanisms of action and clinical applications.
Which is better, Mazdutide or Petrelintide?
Neither is universally "better" - the choice depends on your specific goals. Mazdutide is typically used for weight loss purposes, while Petrelintide is used for weight loss. Always consult with a healthcare provider to determine which may be appropriate for your situation.
Can Mazdutide and Petrelintide be used together?
Some peptide protocols combine multiple compounds for synergistic effects. However, using Mazdutide and Petrelintide 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.