Mazdutide: evidence, legality, and access

Summary

Mazdutide is a once weekly oxyntomodulin analog that activates both the GLP-1 and glucagon receptors, developed primarily in China with a parallel US program. In the 48 week GLORY-1 phase 3 trial of 610 Chinese adults, the 6 mg dose produced 14.0% weight loss versus 0.3% on placebo, and in a 32 week US phase 2 trial (n = 179) the 16 mg dose produced 18.1% versus 0.9%. As of September 2026 it is not FDA approved and cannot lawfully be compounded or sold in the United States; China's drug regulator approved it for chronic weight management in adults in June 2025 and for glycemic control in adults with type 2 diabetes in September 2025, which has no bearing on US legality.

What is Mazdutide?

Mazdutide is a dual agonist of the GLP-1 and glucagon receptors (oxyntomodulin analog, acylated, once weekly). It is also known as IBI362, LY3305677, GLP-1/glucagon dual agonist, mazdutide (IBI362).

How does it work?

Mazdutide is an analog of oxyntomodulin, a gut hormone that naturally activates both the GLP-1 and glucagon receptors. GLP-1 receptor activation reduces appetite, slows gastric emptying, and increases glucose dependent insulin secretion. Glucagon receptor activation raises energy expenditure and liver fat oxidation, which adds to weight loss and improves liver enzymes and lipids. A fatty acid side chain gives a once weekly half life.

Key facts
Cluster	GLP-1 and incretin agonists
Routes	Subcutaneous injection once weekly
Conditions studied	Obesity and chronic weight management; Type 2 diabetes
Record	v2, draft, verified Sep 27, 2026

What does the evidence say about Mazdutide?

Human RCT evidenceGrade assigned per the methodology.

Multiple randomized controlled trials, mostly in China. GLORY-1 (n = 610, 48 weeks) showed 11.0% and 14.0% weight loss at 4 and 6 mg versus 0.3% placebo. A US phase 2 trial (n = 179, 32 weeks) showed 7.3%, 15.6%, and 18.1% at 3 to 6, 10, and 16 mg versus 0.9% placebo. Phase 2 and phase 3 type 2 diabetes trials showed HbA1c reductions of about 1.4 to 1.7 points and superiority to dulaglutide 1.5 mg on weight. A 2026 meta-analysis pooled 9 trials (n = 2,292). No cardiovascular outcomes trial has reported.

Indexed studies by evidence grade
Evidence type	Indexed studies	Participants (human)
Human randomized trials	4	3331
Human observational studies	0	n/a
Animal studies	0	n/a
All indexed studies	4	3,331

Human evidence

GLORY-1 (2025): 610 Chinese adults with BMI 28 or higher (or 24 with a comorbidity), mazdutide 4 mg, 6 mg, or placebo for 48 weeks; weight change at 32 weeks minus 10.1%, minus 12.6%, plus 0.5%, and at 48 weeks minus 11.0%, minus 14.0%, plus 0.3%; 49.5% of the 6 mg group lost at least 15% versus 2.0% on placebo. US phase 2 (2026): 179 adults without diabetes, 32 weeks; weight change minus 7.3% (3 to 6 mg), minus 15.6% (10 mg), minus 18.1% (16 mg) versus minus 0.9% placebo. Phase 2 type 2 diabetes (2024): 250 Chinese adults, 20 weeks; HbA1c change minus 1.41 to minus 1.67 points versus minus 1.35 with dulaglutide and plus 0.03 with placebo, weight up to minus 7.1%. Phase 3 type 2 diabetes trials versus placebo and versus dulaglutide were published in 2026.

Animal evidence

Preclinical rodent studies established the dual receptor pharmacology and additive weight and liver fat effects of glucagon receptor agonism. Thyroid C cell findings are a class expectation for long acting GLP-1 agonists; no FDA label exists.

Key studies

Indexed studies of Mazdutide
Study	Design and population	Outcome	Grade
Once-weekly mazdutide in Chinese adults with obesity or overweight (GLORY-1)2025 PMID 40421736	Randomized, double blind, placebo controlled phase 3 trial, 48 weeksn = 610 Chinese adults with BMI 28 or higher, or 24 to 28 with a weight related condition	Weight change at 48 weeks minus 11.0% (4 mg), minus 14.0% (6 mg), plus 0.3% (placebo); at least 15% loss in 35.7%, 49.5%, and 2.0%	Evidence: Human RCT evidence
Efficacy and safety of mazdutide in adults with obesity or overweight: a US-based phase 2 randomised placebo-controlled trial2026 PMID 42628555	Randomized, double blind, placebo controlled phase 2 trial, 32 weeks (48 week extension)n = 179 US adults without diabetes with BMI 30 or higher	Weight change minus 7.3% (3 to 6 mg), minus 15.6% (10 mg), minus 18.1% (16 mg) versus minus 0.9% placebo	Evidence: Human RCT evidence
Efficacy and safety of mazdutide in Chinese patients with type 2 diabetes: a randomized, double-blind, placebo-controlled phase 2 trial2024 PMID 37943529	Randomized, double blind, placebo and open label dulaglutide controlled phase 2 trial, 20 weeksn = 250 Chinese adults with type 2 diabetes on diet and exercise or metformin	HbA1c change minus 1.41 to minus 1.67 points versus minus 1.35 dulaglutide and plus 0.03 placebo; weight up to minus 7.1%	Evidence: Human RCT evidence
Efficacy and safety of mazdutide in predominantly Chinese adults with obesity and/or type 2 diabetes: a systematic review and meta-analysis2026 PMID 42410325	Systematic review and meta-analysis of 9 randomized controlled trialsn = 2,292 Adults with overweight or obesity and/or type 2 diabetes, predominantly Chinese	Weight reduction versus placebo of 6.6% to 11.1% at 3 to 6 mg in obesity; superior to dulaglutide on weight and HbA1c in type 2 diabetes	Evidence: Human RCT evidence

Conditions studied

Conditions with evidence for Mazdutide
Condition	Grade	Note
Obesity and chronic weight management	Not graded	GLP-1 based peptides are the only peptides with large randomized trials for weight loss. Semaglutide 2.4 mg produced 14.9% mean weight loss over 68 weeks and tirzepatide 15 mg produced 20.9% over 72 weeks. Retatrutide, cagrilintide, and survodutide are in late stage trials.
Type 2 diabetes	Not graded	Several peptide drugs are FDA approved for type 2 diabetes, including insulin, GLP-1 receptor agonists, tirzepatide, and pramlintide. GLP-1 agonists and tirzepatide lower HbA1c by about 1 to 2 percentage points and reduce weight; semaglutide also reduces cardiovascular events.

Is Mazdutide legal in the United States?

Not eligible for compoundingWADA status unclear

FDA and compounding status

Not FDA approved as of the last verification date. Because mazdutide is not a component of an FDA approved drug, has no USP monograph, and is not on the 503A bulks list, it cannot lawfully be compounded or dispensed in the United States, and any product sold as mazdutide in the US is an unapproved drug. Its development and registration have centered on China, where the national drug regulator approved it for chronic weight management in adults (June 2025) and for type 2 diabetes (September 2025); those approvals do not make it legal to sell or compound in the US.

WADA status

WADA status unclear. The current prohibited list does not name this compound explicitly and its class status is not settled. Athletes should ask their anti-doping organization before use.

Regulatory timeline

No regulatory events recorded.

Full tracker for Mazdutide or the category-wide tracker.

What published studies of Mazdutide used

Ranges below are reported from published studies and labeling only. PeptideAgent does not recommend doses or protocols.

GLORY-1: once weekly subcutaneous injection escalated to a maintenance dose of 4 mg or 6 mg. US phase 2: escalated to 3 to 6, 10, or 16 mg weekly. Type 2 diabetes phase 2: 3, 4.5, or 6 mg weekly. No FDA approved label exists; these are trial regimens only.

Routes reported

Routes of administration reported for Mazdutide
#	Route
1	Subcutaneous injection once weekly

What are the side effects and interactions of Mazdutide?

Side effects

Side effects reported for Mazdutide
#	Reported side effect
1	Diarrhea (36% in the type 2 diabetes phase 2 trial)
2	Decreased appetite (29%)
3	Nausea (23%)
4	Vomiting (14%)
5	Hypoglycemia in people with diabetes (10% versus 8% placebo)
6	Gastrointestinal events in general were mostly mild to moderate; discontinuation for adverse events was 1.5% or less in GLORY-1
7	Increased heart rate (glucagon receptor class effect)
8	Long term safety and cardiovascular outcomes not yet reported

Interactions

Interactions reported for Mazdutide
#	Interaction
1	No FDA label, so no formal US interaction studies are published
2	Class precautions apply: hypoglycemia with insulin or sulfonylureas, and altered absorption of oral drugs from delayed gastric emptying
3	Should not be combined with other GLP-1 based agonists (not studied)

Contraindications

Contraindications for Mazdutide
#	Contraindication
1	Not FDA approved; in the United States only available inside registered clinical trials
2	Personal or family history of medullary thyroid carcinoma or MEN2 (class precaution, trial exclusion)
3	Pregnancy and breastfeeding (excluded from trials)
4	Competitive athletes should treat it as prohibited pending confirmation of its approval status with their anti-doping organization

How do people access Mazdutide legally?

Typical cost: Not available through licensed channels in the United States. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity.

Verified access options

Step 1
No lawful United States access path identified on the last verified date outside a registered clinical trial.
Step 2
Not available as an FDA approved product in the United States and not eligible for compounding under section 503A or 503B while investigational.
Step 3
Products labeled research use only are not lawful for human use and are not verified for identity or purity.

Access paths are verified against public regulatory records and prescriber licensing. We never list unlicensed vendors.

Compare Mazdutide

What's actually offered, and what that means for you

Licensed compounding pharmacies, clinics, and telehealth prescribers openly offer many unapproved peptides, and prescribers write prescriptions for them. That does not make mazdutide lawful. Mazdutide is not FDA approved and not on the 503A bulks list, so a pharmacy has no lawful basis to compound it. [7]

Enforcement is uneven. FDA mostly acts through warning letters to online sellers and import alerts that let it detain shipments, rather than stopping every seller. State pharmacy boards oversee pharmacies day to day, and their rules differ. [12] [13] [14]

What changes for you

No FDA review of the product: a product sold outside a trial is an unapproved drug, and FDA has not checked its safety, effectiveness, or quality. [12]
Identity, purity, sterility, and dose accuracy can vary from batch to batch. [12]
Insurance rarely covers it, so you usually pay cash.
For tested athletes, WADA status is unclear; ask your anti-doping organization before any use. [8]

What to check

Mazdutide is not approved in the US, and no check makes a product sold outside a clinical trial lawful. Check for:

Enrollment in a registered clinical trial (ClinicalTrials.gov lists them). Outside a trial, any product sold as mazdutide is an unapproved drug.
Labels such as "research use only" or "not for human consumption", which FDA does not accept for products sold for people. [12]
A licensed prescriber's view on whether an approved drug fits your goal.

For weight management, approved GLP-1 drugs such as tirzepatide and semaglutide are available by prescription. See Tirzepatide, Semaglutide, GLP-1 hub.

Frequently asked questions

Is mazdutide FDA approved or legal in the United States?

No. Mazdutide is not FDA approved as of September 2026, and because it is not a component of an approved drug and is not on any FDA bulks list it cannot be compounded. In the US the only lawful access is a registered clinical trial. It is approved in China for chronic weight management and type 2 diabetes, but a Chinese approval has no bearing on US legality. [6] [7] [9] [10] [11]

How much weight do people lose on mazdutide?

In GLORY-1, a 48 week phase 3 trial of 610 Chinese adults, mean weight loss was 11.0% at 4 mg and 14.0% at 6 mg versus 0.3% on placebo, and about half of the 6 mg group lost at least 15%. In a 32 week US phase 2 trial of 179 adults, higher doses did more: 15.6% at 10 mg and 18.1% at 16 mg versus 0.9% on placebo. The higher US doses are being carried into phase 3. [1] [2]

What are the side effects of mazdutide?

Gastrointestinal effects dominate. In the phase 2 diabetes trial, diarrhea affected 36%, decreased appetite 29%, nausea 23%, and vomiting 14%, with hypoglycemia in 10% versus 8% on placebo. Events were mostly mild to moderate, and in GLORY-1 only 0.5% to 1.5% of treated participants stopped for adverse events. Heart rate rises as with other glucagon receptor agonists. Long term safety and cardiovascular outcomes have not been reported. [1] [3]

How is mazdutide taken?

In trials it is a once weekly subcutaneous injection escalated to a maintenance dose: 4 or 6 mg in GLORY-1, 3 to 6, 10, or 16 mg in the US phase 2 trial, and 3 to 6 mg in the diabetes trials. No FDA approved dosing exists. [1] [2] [3]

How much does mazdutide cost?

It has no US price because it is not on the US market; trial participants receive it free. Any pricing in other countries does not apply to US patients. Products sold as research chemicals are not lawful for human use and are not verified for identity or purity. [6]

Is mazdutide banned by WADA?

Unclear, and athletes should treat it as prohibited. WADA section S0 bans any substance with no current approval by any government health authority for human therapeutic use. Mazdutide is not FDA approved, but China's drug regulator approved it in June 2025; whether that approval takes it outside S0 is a question for the athlete's anti-doping organization. Approved GLP-1 agonists like semaglutide are not prohibited. [8] [10]

Mazdutide vs survodutide: what is the difference?

Both are glucagon/GLP-1 dual agonists and neither is FDA approved. Mazdutide is an oxyntomodulin analog developed mainly in China; survodutide is a glucagon analog developed for obesity and MASH. On weight, mazdutide reached 14.0% at 6 mg over 48 weeks in GLORY-1 and 18.1% at 16 mg over 32 weeks in the US, while survodutide reached 13.0% at 6.0 mg over 76 weeks in SYNCHRONIZE-1. The trials differ in populations and estimands, so this is not a head to head comparison. [1] [2] [5]

Does mazdutide work for type 2 diabetes?

Yes in trials. In the 20 week phase 2 trial of 250 Chinese adults, HbA1c fell 1.41 to 1.67 points with mazdutide versus 1.35 with dulaglutide 1.5 mg and 0.03 with placebo, with up to 7.1% weight loss. Phase 3 trials versus placebo and versus dulaglutide were published in 2026, and a meta-analysis of 9 trials found mazdutide outperformed dulaglutide on both HbA1c and weight. It has no FDA diabetes indication. [3] [4]

Decisions about starting, stopping, or combining any treatment belong with a licensed clinician who knows your history.

From the blog

Peptides for weight loss, ranked by human evidence
Tirzepatide, semaglutide, and liraglutide lead on human trials. Retatrutide is trial-only, and AOD-9604 and 5-amino-1MQ are animal-only. Ranking, legal status, and dated prices.

Sources

Numbered citations above point to these primary sources. PubMed entries link to the indexed abstract.

Cite this page

Free to cite and quote with a link. Data is licensed CC BY 4.0 with attribution to PeptideAgent.

APA style: PeptideAgent. (2026, September 27). Mazdutide: evidence, legality, and access. https://peptideagent.ai/peptides/mazdutide
HTML link: <a href="https://peptideagent.ai/peptides/mazdutide">Mazdutide: evidence, legality, and access</a>, PeptideAgent, updated September 27, 2026.

Mazdutide

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