⚕️ Medical Disclaimer
⚕️ Medical Disclaimer: Trial literacy for mazdutide (IBI362). Not a US dosing protocol. Not medical advice.
What Mazdutide Is
Mazdutide is a once-weekly GLP-1 and glucagon receptor dual agonist developed by Innovent Biologics (IBI362; Lilly discovery-lineage molecule in earlier descriptions). Mechanism class matches the “add glucagon for energy expenditure and hepatic fat oxidation” bet — distinct from tirzepatide’s GIP agonism and MariTide’s GIPR antagonism.
Leaf: /peptides/mazdutide. China approval history for obesity is separate from US availability — do not assume a US pen from a China label.
GLORY-1 Phase 3 — Opened NEJM Numbers
Ji et al., New England Journal of Medicine (once-weekly mazdutide in Chinese adults with obesity or overweight; ClinicalTrials.gov NCT05607680): 610 adults randomized 1:1:1 to mazdutide 4 mg, 6 mg, or placebo for 48 weeks.
At week 32 (treatment-policy estimand), mean percent weight change was −10.09% (4 mg), −12.55% (6 mg), and +0.45% (placebo); ≥5% weight-loss responders were 73.9%, 82.0%, and 10.5%. At week 48, mean changes were −11.00% (4 mg), −14.01% (6 mg), and +0.30% (placebo); ≥15% responders were 35.7%, 49.5%, and 2.0%.
GI adverse events dominated, mostly mild to moderate; discontinuation for adverse events was low in the published summary (about 1.5% / 0.5% / 1.0% across 4 mg / 6 mg / placebo in congress materials). Cardiometabolic secondary measures improved with active drug in the NEJM report framing.
Earlier Velocity Claims vs Phase 3 Reality
Older Phase 2 marketing often emphasized fast early weight-loss velocity. Prefer GLORY-1’s Phase 3 estimands when comparing to global incretin programs. Cross-trial comparisons to STEP or SURMOUNT remain confounded by population (Chinese BMI cutoffs and comorbidity rules differ from many Western trials).
Liver-fat reduction figures sometimes quoted from earlier mazdutide work are not automatically GLORY-1 primary endpoints — cite the specific paper if you use them.
Practical Takeaways
Mazdutide is a serious dual GLP-1/glucagon Phase 3 program with published NEJM obesity data in Chinese adults. It is not tirzepatide, not retatrutide, and not a research-chem substitute for either.
For US patients, labeled options remain the ones with local approvals. Use CalcMyPeptide GLP-1 tools for pens that actually exist in your jurisdiction.