Mazdutide is a once-weekly peptide that acts on the GLP-1 and glucagon receptors. Vendors list it, and a handful of trials have reported on it. We read the trial abstracts on PubMed, a 2025 review of its approval history, an FDA compounding page and the mazdutide listings at the four vendors we review. We are an affiliate partner of one of them, Core Power Peptides, and the link at the end of this page earns us a commission.
What mazdutide is
Mazdutide is a dual agonist of the glucagon receptor and the GLP-1 receptor, developed by Eli Lilly together with Innovent Biologics. A 2025 review in Drugs says China approved it for long-term weight management in June 2025 and for glycaemic control in type 2 diabetes in September 2025 . Tirzepatide acts on GIP and GLP-1 receptors, and retatrutide adds the glucagon receptor to those two. Our post on retatrutide vs tirzepatide and the guide to dual and triple agonist peptides set out the differences.
What the trials measured
Four peer-reviewed trials report human results. We left out every dose, and we read abstracts, not full papers.
Swipe the table sideways to see every column.
| Source | People and length | What it reported |
|---|---|---|
| Ji et al., NEJM 2025 (GLORY-1, phase 3) | 610 Chinese adults with overweight or obesity, 48 weeks, placebo-controlled | At week 48 weight fell 11.00% and 14.01% in the two mazdutide groups and rose 0.30% with placebo. Stopping because of adverse events happened in 1.5% and 0.5% of the mazdutide groups and 1.0% with placebo. Innovent funded it. |
| Gao et al., JAMA 2026 (GLORY-2, phase 3) | 461 Chinese adults treated, BMI of 30 or more, 16.1% with type 2 diabetes, 60 weeks | Weight fell 16.65% with mazdutide and 1.50% with placebo. Vomiting affected 53.1% on mazdutide and 1.3% on placebo, nausea 46.9% and 3.2%, diarrhea 39.4% and 6.5%. |
| Hsia et al., Lancet Diabetes Endocrinol 2026 (phase 2) | 179 US adults without type 2 diabetes, 24 centres, 48 weeks with the main result at 32 | At week 32 weight fell between 7.3% and 18.1% across the mazdutide groups and 0.9% with placebo. Stopping because of adverse events was most common in the highest group, at 20%. Eli Lilly employees are among the authors. |
| Guo et al., Nature 2026 (DREAMS-2, phase 3) | 731 Chinese adults with type 2 diabetes, 28 weeks, against dulaglutide | Both mazdutide groups beat dulaglutide on HbA1c, by 0.24 and 0.30 percentage points, and on weight, by 3.78% and 5.76%. Diarrhoea, nausea and vomiting were the most common adverse events. |
Figures from the GLORY-2 and US phase 2 abstracts. Each pair compares groups inside one trial. Do not compare across the two.
No trial in the table tested a vial from a research vendor, so none says what a vendor's powder contains. Participants followed trial protocols that a vendor listing does not replicate.
Where mazdutide stands with regulators
Beyond the two Chinese approvals above, the review says mazdutide is under clinical evaluation for fatty liver disease, obstructive sleep apnoea and alcohol use disorder . The US trial in the table is phase 2. We found no US approval in the sources we read, and we did not search the FDA's drug database. The FDA's page on bulk substances that may present significant safety risks, current as of 22 April 2026, does not mention mazdutide . A design paper for DREAMS-3, a trial against semaglutide, was published in 2026, and we read no results from it.
What four vendors show for mazdutide
Two of the four vendors we review list a mazdutide vial, and the two list the same size at the same prices.
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| Vendor | What the listing shows | Paperwork it states |
|---|---|---|
| Core Power Peptides | 10mg at $80.00, marked down from $104.00, with 20 in stock | Says it is independently tested to 99%+ purity by HPLC and MS/MS and that a COA is provided. The page has a COA tab. We found no certificate file on the page. No CAS number or molecular weight. |
| Peptides for Sale | 10mg at $80.00, marked down from $104.00, available on backorder | States 99% or more by HPLC. No certificate, CAS number or molecular weight on the page. |
| Peptryn | No mazdutide among its 19 products | Not applicable. |
| American Peptides | No mazdutide among the 82 product pages in its sitemap, read 8 October 2026 | Not applicable. |
Core Power Peptides scores 4 of 6 on our documentation checks, below Peptryn and American Peptides, and the review shows where the gaps are. Our compare page puts all four side by side. A listing that says "COA provided" has not shown you one.
What to ask for before you order
- A certificate that names the lot on your vial, from a lab outside the vendor, with the lab's own contact details.
- The method behind the purity figure (HPLC) and a separate identity result from mass spectrometry, as our guide to reading a certificate of analysis explains.
- The molecular weight the vendor expects, since neither listing states one, so you can check it against the identity result.
Frequently asked questions
Is mazdutide approved?
A 2025 review in Drugs says China approved it for weight management in June 2025 and for type 2 diabetes in September 2025. We found no US approval in our sources. Check the FDA's own database for the current status.
Is mazdutide the same as retatrutide?
No. Mazdutide acts on GLP-1 and glucagon receptors. Retatrutide adds the GIP receptor. They are different molecules with separate trial programs, and our post on retatrutide and tirzepatide covers that compound.
Do vendors publish a mazdutide certificate?
Core Power Peptides says one is provided and shows a COA tab, but we found no file on the page. Peptides for Sale states a purity figure and no certificate. Ask either vendor for the lot report.
What side effects did the trials report?
Gastrointestinal events led. In GLORY-2, vomiting affected 53.1% on mazdutide against 1.3% on placebo, and nausea 46.9% against 3.2%. Most events were mild to moderate in severity, the abstract says.