Summary

Mazdutide (also known as IBI362 or LY3305677) is a dual GLP-1 and glucagon receptor agonist in Phase 3 clinical development for obesity and type 2 diabetes. Developed by Innovent Biologics with licensing involvement from Eli Lilly, it follows the same dual-agonist rationale as survodutide — combining appetite suppression (GLP-1) with increased energy expenditure (glucagon) for enhanced weight loss. Phase 2 data from Chinese populations demonstrated approximately 14.7% weight loss at the 6.0 mg weekly dose over 24 weeks. It is not licensed for use in the UK or any market. For research context only; not for human consumption.

Mechanism

Mazdutide is a dual agonist of the GLP-1 and glucagon receptors. GLP-1 receptor activation reduces appetite, slows gastric emptying, and improves glucose-dependent insulin secretion. Glucagon receptor activation increases energy expenditure, promotes hepatic fat oxidation, and may have direct benefits in fatty liver disease. The combination aims for superior weight loss compared to GLP-1 agonism alone [1].

Evidence base

Phase 2 randomised controlled trial published in Nature Communications (2024) demonstrated ~14.7% weight loss at 6.0 mg weekly over 24 weeks in a Chinese population. Phase 3 trials ongoing. Data limited to single ethnic population and short duration. Evidence graded as moderate — robust Phase 2 human data but Phase 3 confirmation and long-term safety data pending.

Protocols

In clinical trials: subcutaneous injection once weekly, with dose titration from 2.0 mg up to 6.0 mg. Dose escalation at ~2-4 week intervals to manage gastrointestinal side effects. Treatment duration: 24 weeks (Phase 2); longer in Phase 3. Investigational compound not licensed for use outside clinical trials. Research use only.

Mazdutide is not a licensed medicine in the UK. It is available only within approved clinical trials (primarily conducted in China). The MHRA has not granted marketing authorisation. The MHRA has warned about unlicensed weight-loss injectable products sold online [4].

Vendor notes

Not available from UK research peptide vendors. Investigational compound in Phase 3 development only.

References

  1. Innovent Biologics. Mazdutide (IBI362) — Dual GLP-1/Glucagon Receptor Agonist. Clinical development programme. ClinicalTrials.gov. https://clinicaltrials.gov/search?term=mazdutide
  2. Ji L, Jiang H, Zhang Y, et al. Once-Weekly Mazdutide in Chinese Adults with Obesity: A Randomised, Double-Blind, Placebo-Controlled, Multiple-Dose Phase 2 Study. Nature Communications, 2024. DOI: 10.1038/s41467-024-46727-3.
  3. Innovent Biologics. Mazdutide Phase 3 clinical trial programme (obesity and type 2 diabetes). ClinicalTrials.gov. https://clinicaltrials.gov/search?term=mazdutide
  4. Medicines and Healthcare products Regulatory Agency (MHRA). MHRA warns the public about unlicensed weight loss injections and medicines sold online. GOV.UK. https://www.gov.uk/government/news/mhra-warns-public-about-unlicensed-weight-loss-injections-and-medicines-sold-online