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Fat loss

Mazdutide

Dual GLP-1/glucagon agonist in Phase 3 trials showing 15-20% weight loss with metabolic benefits beyond weight reduction.

Investigational (Phase 3) Fat loss Longevity

Reviewed 2026-09-12
Full name
LY3305677 (dual glucagon and GLP-1 receptor agonist)
Also known as
LY3305677, GCG/GLP-1 dual agonist
Regulatory status
Investigational (Phase 3) | Positive Phase 2 data

Origin

Developed by Eli Lilly and Innovent Biologics as a once-weekly subcutaneous GLP-1/glucagon dual agonist. Moved from Phase 1 through Phase 2 US trials to Phase 3 in Chinese populations, with 15-20% weight loss.

Mechanism

Near-equipotent agonist at GLP-1 and glucagon receptors (GCGR). GLP-1R activation suppresses appetite; GCGR activation raises hepatic and peripheral lipid oxidation and energy expenditure. The glucagon component may preferentially mobilize visceral and hepatic fat.

Research summary

Evidence

Phase 2 US trial: 10-16 mg produced 15.6-18.1% weight loss at week 32 vs -0.9% for placebo. Phase 3 China data show up to 20.1% weight loss. GI adverse events are dose-limiting, worst at 16 mg (20% discontinuation). Cardiovascular safety is still being evaluated in ongoing outcomes trials.

Evidence tier: Investigational (Phase 3) — see the methodology note for how this is assessed.

Citations

Reported benefits

  • weight loss (15-20% body weight reduction)
  • reduced waist circumference
  • improved glycemic control
  • preferential visceral/hepatic fat loss
  • potential kidney protection

Dosing protocols reported in the literature & community

These are protocols reported by compounding pharmacies, published trials, or self-experimentation communities — not a prescription. Start low, especially for anything new.

Reported dosing protocols
RouteReported protocol
Subcutaneous injectionOnce-weekly: dose escalation from 3 mg to maintenance of 10 mg or 16 mg depending on tolerability.

Side effects

  • nausea
  • vomiting
  • diarrhea
  • constipation
  • abdominal pain
  • increased heart rate
  • fatigue

Safety notes

Safety: GI toxicity is dose-limiting at 16 mg. Heart rate rises at all doses. Cardiovascular outcomes trial ongoing. No teratogenicity data; not studied in pregnancy.
Community & reddit notes (anecdotal — not clinical evidence)

Access for self-experimenters is limited since it's still a Phase 3 drug. Trial participants report more weight loss and stronger appetite suppression than semaglutide alone.

Mixing compatibility

Pulled from a community-charted mixing-compatibility reference (anecdotal, clinic-use, and community-reported signals) — not a safety guarantee. Verify independently before combining anything.

Note: This chart's source flags GLP-1/GIP/glucagon-receptor drugs as broadly avoided in combination with other research peptides across the board — not a peptide-specific interaction, more a general caution against stacking incretin drugs with anything else. Treat any combination here as unverified.