Metabolic / Weight Loss · 5mg × 10 vials
think of mazdutide as "retatrutide minus the GIP arm".
Mazdutide (IBI-362 / LY3305677) is a once-weekly injectable peptide that hits two metabolic receptors at once: GLP-1 (the "Ozempic pathway", appetite suppression + slowed gastric emptying) and the glucagon receptor (drives the liver to burn fat for energy, bumps total energy expenditure, improves hepatic fat metabolism). Structurally it's a synthetic analog of oxyntomodulin, the naturally occurring gut hormone that the body produces post-meal to do exactly this dual-receptor job. A fatty-acyl chain has been bolted on to extend the half-life to ~7-8 days, which is what allows the once-weekly dosing. In plain language: think of mazdutide as "retatrutide minus the GIP arm". You get the appetite suppression of semaglutide stacked with the fat-metabolism push of the glucagon receptor, but you don't get the GIP-driven insulin amplification that tirzepatide and retatrutide use to soften nausea. The trade-off is more upfront GI side effects than reta but a much cleaner discontinuation rate, and the published efficacy lands in the 15-20% body weight loss band, which is squarely above semaglutide and approaching the lower end of retatrutide and tirzepatide top doses.
Typical dose ranges by experience level - educational reference. Message us and we tailor it to you.
Phase 3 GLORY-1 protocol started at 3 mg with 4-week step-ups. Community consensus is the same as reta: the trial schedule is too aggressive for first-timers because the glucagon arm punches harder on nausea than pure GLP-1 does. 5 mg vial + 1 ml BAC = 5 mg/ml, so 1.5 mg = 0.30 ml = 30 IU on a U-100 syringe. Inject subQ into abdomen or outer thigh, rotate sites.
GLORY-1 Phase 3 at 6 mg averaged 12.55% body weight loss at 32 weeks (mean weight loss had not plateaued at trial end). DREAMS-3 head-to-head vs semaglutide 1 mg showed mazdutide 6 mg delivered 10.29% weight loss vs sema's 6.0% at 32 weeks, plus better glycemic control. This band is where the body composition reads start matching tirzepatide top doses. Resting heart rate creep of ~3-5 bpm is the standard signal at this band, check resting HR weekly, hold dose if it climbs >15 bpm above baseline.
GLORY-2 Phase 3 (announced Nov 2025) at 9 mg averaged 18.55% body weight loss vs 3.02% placebo over 48 weeks, with 44% of participants hitting ≥20% loss. Phase 1b at 10 mg saw 11.7% loss at week 12, suggesting the curve keeps climbing past 9 mg but the AE rate also climbs. Discontinuation due to AEs at 6 mg in GLORY-1 was 0.5% (vs 1.0% placebo), which is dramatically cleaner than retatrutide's 11.3% at 12 mg, the main practical advantage of mazdutide over reta.
Straight talk - what people actually report, and what the studies measured.
Peer-reviewed studies and clinical guidelines - tap any to read the source.
, NEJM 2025](https://www.nejm.org/doi/full/10.1056/NEJMoa2411528) - pivotal Phase 3, 610 pts, 48 wk, 12.55% loss at 6 mg
Read study ↗PubMedSafety and efficacy of mazdutide 9/10 mg Phase 1b, eClinicalMedicine 2022 (PMC9561728)](https://pmc.ncbi.nlm.nih.gov/articles/PMC9561728/) - high-dose Phase 1b safety/efficacy
Read study ↗PubMedMazdutide reduces body weight Phase 1 high-dose trial, DOM 2025 (PMC12515780)](https://pmc.ncbi.nlm.nih.gov/articles/PMC12515780/) - high-dose pharmacokinetics
Read study ↗PubMedPhase 2 RCT mazdutide in Chinese overweight adults, eClinicalMedicine 2023 (PMC10719339)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10719339/) - Phase 2 dose-response
Read study ↗PubMedMazdutide GLP-1R/GCGR dual agonist mitigates diabetes-associated cognitive dysfunction, eBioMedicine 2025 (PMC12205698)](https://pmc.ncbi.nlm.nih.gov/articles/PMC12205698/) - mechanism beyond weight
Read study ↗PubMedCase Report dose-escalated mazdutide in adolescent (PMC12477040)](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12477040/) - real titration case
Read study ↗Aggregated sentiment from public forums & socials - real-world reports, not individual endorsements.
Nausea: most-reported sensation, peaks weeks 2-6, noticeably more upfront punch than reta because there's no GIP arm to soften it. Most users describe it as "manageable but real" if you start at 1.5 mg, "brutal" if you start at the trial-protocol 3 mg.
Fatigue: similar pattern to reta but resolves faster, often a one-week "blah" after each titration step
No dysesthesia / sunburn-feeling skin: this is a retatrutide-specific signal and does NOT show up on mazda, one of the cleaner reasons users switch from reta
Loss of taste / food aversion: reported but milder than reta or tirz at equivalent loss levels
Sulfur burps: less common than on semaglutide
Heart rate awareness: smaller than reta, users self-tracking commonly see +3-5 bpm resting HR; usually settles by week 8
Route: SubQ
Injection site: abdomen or outer thigh, rotate sites
Storage: refrigerated 2-8°C, ~28 days after reconstitution. Lyophilized vials stored at -20°C long-term, room-temp shipping is fine short-term. Avoid freeze-thaw cycles.
Notes: Morning injection on a low-fat day reduces nausea (same pattern as reta). Allow vial to reach room temp before injecting once mixed. Use a fresh insulin syringe per draw, don't shake the vial (swirl gently to mix). The glucagon arm makes the first 2-4 weeks of any titration step noticeably more nauseous than equivalent reta or tirz steps, so don't rush.