Retatrutide vs Mazdutide: Triple Agonist vs Dual Agonist, Lilly vs Innovent

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> Reviewed by FormBlends Medical Team · Last updated May 2026 · 11 sources cited

Investigational drug notice

Retatrutide is investigational and not approved in the U.S., EU, or any major market as of May 2026. Mazdutide is approved in China only. Neither drug is legally available in the United States. FormBlends does not sell, supply, prescribe, or facilitate access to retatrutide or mazdutide. This article is educational and references published clinical trial data.

Key Takeaways

• Mazdutide is a GLP-1/glucagon dual agonist; retatrutide is a GLP-1/GIP/glucagon triple agonist
• Both molecules originated in Eli Lilly's pipeline; mazdutide was licensed to Innovent Biologics for Chinese development
• Mazdutide is approved in China for obesity (June 2025) as Xinmaihe; retatrutide is investigational globally
• Cross-trial: retatrutide phase 2 produced ~24% weight loss; mazdutide phase 3 in Chinese populations produced ~14-15% at top doses over similar durations
• The GIP component in retatrutide is the main mechanistic difference and probably explains most of the efficacy gap

Direct answer

Mazdutide and retatrutide are different classes of incretin drug. Mazdutide hits two receptors (GLP-1 and glucagon). Retatrutide hits three (GLP-1, GIP, glucagon). Trial data shows retatrutide produced more weight loss than mazdutide in cross-population comparison. Neither drug is legally available in the U.S. Mazdutide has Chinese approval; retatrutide is in phase 3 trials. For U.S. patients in 2026, both are theoretical options at best.

Table of contents

1. The mazdutide story: from Lilly molecule to Chinese approval
2. The retatrutide story: triple-agonist development
3. Mechanism: why three receptors usually beat two
4. Mazdutide trial data: GLORY and DREAMS programs
5. Retatrutide phase 2 data review
6. Cross-trial weight-loss comparison
7. Population differences: Chinese vs Western trial cohorts
8. Regulatory status in the U.S., EU, China
9. Side effect profiles compared
10. The contrary view: more receptors is not always better
11. FAQ
12. Sources

The mazdutide story: from Lilly molecule to Chinese approval

Mazdutide began life as LY3305677 in Eli Lilly's pipeline, a GLP-1/glucagon dual agonist designed in the late 2010s. Lilly licensed Chinese development and commercialization rights to Innovent Biologics, a Suzhou-based biopharma, in 2019. Innovent ran the phase 2 and phase 3 trial program in Chinese populations under the GLORY (in obesity) and DREAMS (in type 2 diabetes) banners.

The phase 3 obesity data (GLORY-1) reported in 2024 supported a regulatory submission to China's National Medical Products Administration. NMPA approved mazdutide for chronic weight management in adults with obesity in June 2025, with the brand name Xinmaihe. The approved doses are 4 mg and 6 mg weekly.

Innovent has discussed expanding mazdutide outside China, but no FDA, EMA, or other major-market submission has been announced. The molecule remains a China-first product in 2026.

The retatrutide story: triple-agonist development

Retatrutide (Lilly internal code LY3437943) is a different molecule, designed from the start as a triple agonist. The development trajectory ran phase 1 in 2020, phase 2 readouts in obesity (2023) and type 2 diabetes (2023), and phase 3 TRIUMPH trials starting in 2022 with anticipated readouts beginning 2025-2026.

Lilly retained full global rights. The TRIUMPH program targets U.S. and global registration. Approval timelines (FDA, EMA) are projected for 2027-2028 if trials read out as expected.

The strategic context is that Lilly has multiple incretin-class assets in parallel: tirzepatide (approved), mazdutide (licensed to Innovent), retatrutide (next-generation). Each targets slightly different patient populations and metabolic profiles. The portfolio approach hedges against any single molecule underperforming in late-stage trials.

Mechanism: why three receptors usually beat two

GLP-1 alone (semaglutide): appetite reduction, slowed gastric emptying, glucose-dependent insulin secretion. Produces ~15% mean weight loss in obesity trials.

GLP-1 + GIP (tirzepatide): adds amplified satiety and improved glucose handling. Produces ~22% mean weight loss.

GLP-1 + glucagon (mazdutide): adds energy-expenditure increase and hepatic fat oxidation, but loses the GIP boost. Phase 3 Chinese data showed ~14-15% mean weight loss at top dose, lower than tirzepatide.

GLP-1 + GIP + glucagon (retatrutide): combines all three. Phase 2 showed ~24% mean weight loss at top dose.

The pattern is informative. Each receptor adds something distinct. Glucagon alone (on a GLP-1 base) does not match GIP alone for weight loss in this cross-comparison, but glucagon adds metabolic effects (liver fat, energy expenditure) that GIP does not. The triple agonist captures both.

Important caveat: the GLORY-1 mazdutide trial enrolled a Chinese population with lower mean baseline BMI (around 31) than Western retatrutide and tirzepatide trials (mean BMI 37-38). Lower-baseline populations typically lose smaller absolute amounts of weight, which compresses percentage figures. The mazdutide numbers in a Western trial might be higher than what GLORY-1 reported.

Mazdutide trial data: GLORY and DREAMS programs

Mazdutide phase 3 data in obesity (GLORY-1):

• Sample size: 610 adults with BMI ≥28 (Chinese obesity criterion, lower than the Western ≥30 threshold)
• Duration: 48 weeks
• Doses tested: 4 mg and 6 mg weekly
• Mean weight loss at 6 mg: approximately 14.4%
• Mean weight loss at 4 mg: approximately 11.0%
• Placebo: approximately 0.3%
• Categorical ≥5% loss: ~85% at 6 mg
• Common adverse events: nausea, diarrhea, decreased appetite, dose-dependent

Mazdutide phase 3 data in type 2 diabetes (DREAMS-1, DREAMS-2): showed HbA1c reductions of 1.5-2.0% at 6 mg with concurrent weight loss in T2D patients. The diabetes program supported a second NMPA indication submission.

Retatrutide phase 2 data review

The retatrutide phase 2 trial (Jastreboff et al., NEJM 2023):

• Sample size: 338 adults without diabetes
• Duration: 48 weeks
• Doses: 1, 4, 8, 12 mg weekly
• Mean weight loss: 8.7% (1 mg), 17.1% (4 mg), 22.8% (8 mg), 24.2% (12 mg)
• Mean baseline BMI: 37.3
• Population: U.S. and international trial sites, predominantly Western
• Categorical ≥25% loss at 12 mg: 48%

The retatrutide diabetes phase 2 (Rosenstock et al., Lancet 2023) showed HbA1c reductions and concurrent weight loss in T2D patients similar to the obesity profile.

Cross-trial weight-loss comparison

	Mazdutide GLORY-1	Retatrutide phase 2
Phase	Phase 3	Phase 2
Region	China	U.S., international
Duration	48 weeks	48 weeks
Mean baseline BMI	~31	~37.3
Top dose	6 mg weekly	12 mg weekly
Mean weight loss at top dose	~14.4%	~24.2%
Mechanism	GLP-1 + glucagon	GLP-1 + GIP + glucagon
Approval status	China (June 2025)	Investigational

The 10 percentage point gap is real but is confounded by the BMI and population differences. A reasonable adjustment: in a matched Western population at BMI 37, mazdutide might produce 17-19% weight loss, which would narrow the gap with retatrutide to perhaps 5-7 percentage points. That estimate is speculative.

Population differences: Chinese vs Western trial cohorts

Chinese obesity trials differ from Western trials in several ways that affect comparison:

• BMI thresholds. China defines obesity as BMI ≥28; Western definitions use ≥30. Chinese trial populations therefore tend to have lower mean baseline BMI
• Body composition. East Asian populations carry visceral fat at lower BMIs than Western populations on average. Cardiometabolic risk at BMI 28-30 in a Chinese cohort may be comparable to BMI 32-34 in a Western cohort
• Diet and lifestyle baseline. Caloric patterns, macronutrient profiles, and physical activity baselines differ between trial populations
• Genetic factors. Drug metabolism and response can vary across populations; specific data for mazdutide and retatrutide pharmacogenomics is limited

The honest implication: cross-population comparison should be treated with even more caveats than cross-trial comparison within a region. Population-matched head-to-head trials are the only way to settle which drug performs better in a specific patient profile.

Regulatory status in the U.S., EU, China

Region	Mazdutide	Retatrutide
U.S. (FDA)	Not approved, no submission filed	Investigational, phase 3 ongoing, projected submission 2026-2027
EU (EMA)	Not approved, no submission filed	Investigational, no submission filed
China (NMPA)	Approved June 2025 (Xinmaihe) for obesity	Phase 3 trials include Chinese sites; no submission filed
U.K. (MHRA)	Not approved	Not approved
Canada (Health Canada)	Not approved	Not approved

Side effect profiles compared

Mazdutide GLORY-1 reported nausea (~26% at 6 mg), diarrhea (~17%), and decreased appetite (~15%). Discontinuation due to adverse events ran around 4-7% across active arms.

Retatrutide phase 2 reported nausea (~36% at 12 mg), diarrhea (~27%), vomiting (~16%), and discontinuation rates of 6-12%.

The raw rates appear lower for mazdutide, but the comparison is again confounded by population, dosing, and trial design. The qualitative profiles match the GLP-1 class. There are no fundamental differences in adverse event categories. Phase 3 retatrutide data will firm up the comparison once published.

The contrary view: more receptors is not always better

The "triple agonist beats dual agonist" framing has appeal but is not a clinical law. Reasons to take it with appropriate caution:

Complexity costs. A molecule that activates three receptors has more pharmacologic interactions to manage. The phase 2 retatrutide data is favorable, but rare or long-latency adverse events may emerge in phase 3 or post-marketing. A simpler dual agonist (or even a single agonist) carries less mechanistic risk.

Specific use cases for narrower targeting. Mazdutide's glucagon-driven hepatic effects may make it well-suited for patients where liver fat reduction is the primary goal and the additional weight loss from GIP is less needed. The "best drug" depends on what you are trying to achieve.

Cost and access trade-offs. A more potent drug typically commands premium pricing. For a patient where 14% weight loss meets clinical goals, a less expensive option (semaglutide, mazdutide if accessible) may be preferable to a more expensive option that produces incrementally more weight loss the patient does not need.

Population-specific response. Some patient subgroups may respond well to GLP-1 monotherapy and not gain much from adding GIP or glucagon. Without robust head-to-head data within subgroups, the "triple beats dual" claim is a population-level generalization.

The honest framing: retatrutide is probably the most potent option on a population basis. The right drug for a specific patient depends on goals, access, and individual response.

FAQ

Is mazdutide available in the U.S.? No. It is approved in China only.

What does Xinmaihe mean? Xinmaihe is the Chinese brand name for mazdutide under Innovent Biologics' commercialization. The name does not have an established English meaning in international literature.

Will retatrutide be more expensive than mazdutide? Likely yes in markets where both are available. Triple agonists are more complex molecules to manufacture, and Lilly will price retatrutide as a premium product. Chinese mazdutide pricing under NMPA approval is below typical Western branded incretin prices.

Is mazdutide compounded available? No legitimate U.S. compounding pathway exists for mazdutide. The drug is not on FDA shortage lists and is not approved.

What other glucagon-containing incretin drugs are in development? Survodutide (Boehringer Ingelheim/Zealand, GLP-1/glucagon dual agonist) is in phase 3. Cotadutide and pemvidutide are other GLP-1/glucagon molecules in earlier stages. The class is active.

Did Lilly make a strategic mistake licensing mazdutide? Hard to say. Lilly retained China-economic upside from mazdutide while focusing internal resources on retatrutide and tirzepatide. The licensing strategy de-risked an early-pipeline molecule and produced a Chinese-market product, which Lilly might not have prioritized otherwise.

How safe is glucagon receptor activation long term? The 48-week phase 2 retatrutide data showed no new safety signals. Mazdutide phase 3 in Chinese populations was similarly clean. Glucagon-mediated effects on cardiac function, hepatic glucose output, and amino acid metabolism are theoretical concerns that longer follow-up may or may not validate.

Related guides

• Mazdutide vs Retatrutide: Dual vs Triple, China vs U.S., Approved vs Investigational
• Retatrutide vs Survodutide: Dual vs Triple Agonist Comparison 2026
• Retatrutide: Complete Guide to Eli Lilly's Triple Agonist
• What Is Survodutide? A Dual GLP-1/Glucagon Agonist Built for More Than Weight Loss
• Survodutide for MASH: How a Dual Agonist Targets the Liver
• Survodutide for MASH: Boehringer's Dual Agonist, Closer Look

Sources

1. Jastreboff AM, Kaplan LM, Frias JP, et al. Triple-Hormone-Receptor Agonist Retatrutide for Obesity, A Phase 2 Trial. New England Journal of Medicine. 2023;389:514-526.
2. Rosenstock J, Frias J, Jastreboff AM, et al. Retatrutide in Type 2 Diabetes: A Phase 2 Trial. The Lancet. 2023;402:529-540.
3. Ji L, Jiang H, Bi Y, et al. Mazdutide Once Weekly for the Treatment of Obesity (GLORY-1): A Phase 3 Trial. Innovent Biologics published trial data and CSR summaries, 2024.
4. Innovent Biologics press releases on Xinmaihe NMPA approval, June 2025.
5. National Medical Products Administration (China). Approval notice for mazdutide injection, June 2025.
6. Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). New England Journal of Medicine. 2022;387:205-216.
7. Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1). New England Journal of Medicine. 2021;384:989-1002.
8. Eli Lilly and Company. Licensing agreement summary with Innovent Biologics, 2019.
9. ClinicalTrials.gov. Mazdutide GLORY and DREAMS phase 3 trial identifiers.
10. ClinicalTrials.gov. Retatrutide TRIUMPH-1 through TRIUMPH-5 phase 3 program.
11. Endocrine Society Clinical Practice Guideline on Pharmacological Management of Obesity, 2024 Update.

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Investigational Drug Notice. Retatrutide is investigational and not approved in the U.S. Mazdutide is approved in China only and is not available in the U.S. through any legal channel. FormBlends does not sell, supply, or facilitate access to either investigational or foreign-approved unapproved drugs.

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