Evidence-Based Summary
There is no head-to-head trial, so no one can say which works better. Mazdutide's Phase 3 evidence comes mainly from Chinese adults (GLORY-1 for weight, plus type 2 diabetes trials against placebo and against dulaglutide), with one 179-person U.S. Phase 2 trial. It was approved in China in 2025 but is not FDA-approved, and FDA has warned companies selling it online as a "research" product. Tirzepatide is FDA-approved as Mounjaro and Zepbound and has large multinational Phase 3 programs, two direct trials against semaglutide and a cardiovascular outcomes trial against dulaglutide. Weight-loss percentages from separate trials differ in population, duration, BMI criteria and analysis method, so placing them side by side does not rank the two drugs.
Quick Comparison: Mazdutide vs Tirzepatide
A high-level comparison of molecule class, molecular receptor targets, FDA regulatory approvals, and verified clinical programs.
| Feature | Mazdutide | Tirzepatide |
|---|---|---|
| Drug class | Dual GLP-1 and glucagon receptor agonist; investigational in the U.S. | Dual GIP and GLP-1 receptor agonist; FDA-approved |
| Target receptors | GLP-1 receptor and glucagon receptor | GIP receptor and GLP-1 receptor |
| How it is given | Once-weekly injection under the skin (as studied in trials) | Once-weekly injection under the skin |
| U.S. regulatory status | Not FDA-approved. Approved in China in 2025 for weight management and type 2 diabetes | FDA-approved: Mounjaro (type 2 diabetes) and Zepbound (weight management; obstructive sleep apnea with obesity) |
| Strongest human evidence | Phase 3 trials in Chinese adults; one U.S. Phase 2 obesity trial | Multinational Phase 3 programs, two direct trials versus semaglutide and a cardiovascular outcomes trial versus dulaglutide |
| Main safety concerns | Gastrointestinal effects (diarrhoea, nausea, vomiting); long-term safety not established | Gastrointestinal effects; boxed warning for thyroid C-cell tumors seen in rodents; pancreatitis and gallbladder warnings |
| Direct comparison trial | None published | None published |
| WADA status (2026) | Not named on the Prohibited List; check with your anti-doping organization | Not named on the Prohibited List; check the current list before competition |
How Mazdutide and Tirzepatide Act at the Receptor Level
Both molecules activate the GLP-1 receptor, which helps glucose-dependent insulin release and reduces appetite. They differ in their second target. Activating an extra receptor does not, by itself, prove a better clinical result.
Mazdutide
Primary Target: GLP-1 and glucagon receptors
Affinity Profile: Dual receptor agonist (GLP-1 plus glucagon)
Glucagon receptor activity is the main pharmacological difference from GLP-1-only drugs and from tirzepatide. The published trials test the whole molecule; they do not isolate what each receptor contributes to weight or glucose changes.
Tirzepatide
Primary Targets: GIP and GLP-1 receptors
Affinity Profile: Dual receptor agonist (GIP plus GLP-1)
Activates both incretin receptors. As with mazdutide, human trials measure the effect of the whole medicine rather than separating the GIP and GLP-1 contributions.
U.S. Approval Status and Approvals Elsewhere
Checked 11 October 2026 against Drugs@FDA, DailyMed and FDA communications. An approval outside the U.S. does not make a product approved or legal to sell in the U.S.
Mazdutide Status & Formulations
United States: not FDA-approved; no Drugs@FDA or DailyMed record. China: Innovent announced NMPA approval for chronic weight management in adults (June 2025) and for glycaemic control in adults with type 2 diabetes (September 2025). Eli Lilly sponsors U.S. development; a Phase 2 obesity trial has been published.
Tirzepatide Status & Formulations
United States: Mounjaro is indicated for glycemic control in adults and children aged 10 years and older with type 2 diabetes. Zepbound is indicated for defined adult weight-management uses and for moderate-to-severe obstructive sleep apnea in adults with obesity. Each label has its own eligibility criteria and limitations.
Critical Regulatory Distinction
FDA lists mazdutide among unapproved drugs that companies have illegally sold as "for research purposes" or "not for human consumption". Such products have not been reviewed by FDA for identity, purity or sterility, and they are not equivalent to the Chinese medicine or to an FDA-approved drug.
What Each Trial Program Has Shown
The two programs studied different populations (mostly Chinese adults for mazdutide; multinational populations for tirzepatide), for different lengths of time, with different BMI cut-offs and analysis methods. The numbers below describe each drug against its own comparator, not against each other.
Mazdutide: Clinical Evidence Overview
GLORY-1 randomized 610 Chinese adults with a BMI of 28 or more, or 24 to under 28 with a weight-related condition. At week 48, mean weight change was −11.0% and −14.0% in the two mazdutide groups versus +0.3% with placebo. In 731 Chinese adults with type 2 diabetes, both mazdutide groups lowered HbA1c more than dulaglutide at 28 weeks (differences −0.24 and −0.30 percentage points) and reduced body weight more (differences −3.8% and −5.8%). A U.S. Phase 2 trial in 179 adults without diabetes reported weight changes of −7.3% to −18.1% across mazdutide groups at 32 weeks versus −0.9% with placebo. No cardiovascular outcomes trial has been published.
Tirzepatide: Clinical Evidence Overview
SURMOUNT-1 randomized 2,539 adults with obesity or overweight without diabetes; at 72 weeks mean weight change was −15.0%, −19.5% and −20.9% across three tirzepatide groups versus −3.1% with placebo. SURMOUNT-5 compared tirzepatide directly with semaglutide in 751 adults without diabetes (−20.2% vs −13.7% at 72 weeks). SURPASS-CVOT randomized 13,299 people with type 2 diabetes and atherosclerotic cardiovascular disease: cardiovascular death, heart attack or stroke occurred in 12.2% with tirzepatide versus 13.1% with dulaglutide (HR 0.92, 95.3% CI 0.83–1.01), meeting noninferiority but not superiority.
Curated Clinical Evidence Table
A curated selection of the primary studies behind each compound’s evidence profile. Results from different studies are not directly comparable.
| Study & Citation | Population | Comparison & Dosing | Duration | Main Endpoint | Key Finding | Methodological Limitations |
|---|---|---|---|---|---|---|
| GLORY-1 (Ji et al., NEJM 2025) | 610 Chinese adults with obesity or overweight | Two mazdutide doses vs placebo | 48 weeks | Percentage change in body weight | −11.0% and −14.0% vs +0.3% with placebo at week 48. | Chinese adults and Chinese BMI cut-offs only; funded by Innovent. |
| Mazdutide vs dulaglutide (Guo et al., Nature 2026) | 731 Chinese adults with type 2 diabetes on oral drugs | Two mazdutide doses vs dulaglutide | 28 weeks | Change in HbA1c | HbA1c differences −0.24 and −0.30 points vs dulaglutide; weight differences −3.8% and −5.8%. | Short; one comparator; more gastrointestinal events with mazdutide. |
| U.S. Phase 2 (Hsia et al., Lancet Diabetes Endocrinol 2026) | 179 U.S. adults with obesity or overweight, no diabetes | Three mazdutide regimens vs placebo | 48 weeks (primary endpoint at 32) | Percentage change in body weight at 32 weeks | −7.3% to −18.1% vs −0.9% with placebo. | Small Phase 2 trial; 20% stopped treatment for adverse events in the highest-dose group. |
| SURMOUNT-1 (Jastreboff et al., NEJM 2022) | 2,539 adults with obesity or overweight, no diabetes | Three tirzepatide doses vs placebo | 72 weeks | Percentage change in body weight | −15.0%, −19.5% and −20.9% vs −3.1% with placebo. | Placebo-controlled; cannot be compared directly with GLORY-1. |
| SURMOUNT-5 (Aronne et al., NEJM 2025) | 751 adults with obesity, no diabetes | Tirzepatide vs semaglutide | 72 weeks | Percentage change in body weight | −20.2% vs −13.7% (P<0.001). | Open-label; industry-funded; does not involve mazdutide. |
| SURPASS-CVOT (Nicholls et al., NEJM 2025) | 13,299 adults with type 2 diabetes and atherosclerotic disease | Tirzepatide vs dulaglutide | Event-driven | Cardiovascular death, heart attack or stroke | 12.2% vs 13.1%; HR 0.92 (95.3% CI 0.83–1.01); noninferior, not superior. | Active comparator; no equivalent outcomes trial exists for mazdutide. |
Adverse Effects and Label Warnings
Gastrointestinal effects were the most common adverse events for both drugs in trials. Tirzepatide has a full U.S. label; mazdutide has no FDA label, so U.S. labelling comparisons are one-sided.
FDA Boxed Warning (tirzepatide labels): Risk of Thyroid C-Cell Tumors
Mounjaro and Zepbound carry a boxed warning for thyroid C-cell tumors seen in rodents; whether tirzepatide causes them in humans is unknown. Both are contraindicated with a personal or family history of medullary thyroid carcinoma or MEN 2. Mazdutide has no FDA label, so no equivalent U.S. warning exists; that is not evidence that it lacks the risk.
Unapproved "research" mazdutide
FDA has warned companies that illegally sold unapproved drugs containing mazdutide labelled "for research purposes" or "not for human consumption", sometimes with dosing instructions. These products have no FDA review of identity, purity or sterility.
| Safety Consideration | Mazdutide | Tirzepatide |
|---|---|---|
| Most common adverse events in trials | Diarrhoea, nausea and vomiting; more gastrointestinal events than dulaglutide in the 28-week comparison | Nausea, diarrhoea, vomiting and other gastrointestinal effects, mostly during dose escalation |
| Stopping because of adverse events | 1.5% and 0.5% vs 1.0% with placebo in GLORY-1; 20% in the highest-dose group of the U.S. Phase 2 trial | 4.3% to 7.1% across tirzepatide groups vs 2.6% with placebo in SURMOUNT-1 |
| U.S. label warnings | No FDA label | Thyroid C-cell tumor boxed warning; pancreatitis, gallbladder disease, hypoglycemia with insulin or secretagogues, dehydration-related kidney injury |
| Long-term and outcomes data | Trials up to 48 weeks; no cardiovascular outcomes trial | Cardiovascular outcomes trial versus dulaglutide (SURPASS-CVOT) |
Specific Drug Interaction Note
Tirzepatide labels advise switching to a non-oral contraceptive method, or adding a barrier method, for four weeks after starting and after each dose increase, because slowed stomach emptying may reduce absorption of oral contraceptives. No comparable U.S. guidance exists for mazdutide.
What Mazdutide and Tirzepatide Have in Common
Where the two compounds overlap in biology, evidence or regulatory context.
Shared GLP-1 receptor activity
Both activate the GLP-1 receptor and are given as once-weekly injections.
Gastrointestinal side effects
Nausea, diarrhoea and vomiting were the most common adverse events for both in randomized trials.
Weight and glucose trial evidence
Both lowered body weight against placebo and lowered HbA1c in type 2 diabetes in randomized trials.
Key Scientific & Clinical Differences
Meaningful distinctions in mechanism, strength of evidence, safety and regulatory status.
Different second receptor
Mazdutide adds glucagon receptor activity; tirzepatide adds GIP receptor activity.
Regulatory status
Tirzepatide is FDA-approved for specific indications. Mazdutide is approved only in China and is investigational in the U.S.
Breadth of evidence
Tirzepatide has multinational Phase 3 programs, direct trials against semaglutide and a cardiovascular outcomes trial. Mazdutide's Phase 3 data come mostly from Chinese adults.
Scientific Comparison vs Clinical Recommendations
Inside Peptides compares scientific evidence, receptor pharmacology, and official regulatory documents to advance public and professional understanding. We do not determine which compound is appropriate for an individual patient, rank medications with arbitrary scores, or recommend initiating or switching treatments.
Decisions about any medicine require a licensed healthcare professional who can weigh personal medical history, contraindications, interactions and monitoring needs. Unapproved peptides have no established safe use, and products sold as “research chemicals” are not the preparations studied in clinical research.
Approved Uses vs Online Claims
A critical scientific distinction between verified, FDA-approved clinical uses and unverified claims circulating on social media and vendor platforms.
Mazdutide is a stronger next-generation tirzepatide
Not supportedMazdutide is not FDA-approved; tirzepatide is approved for specific labelled uses.
No randomized trial has compared the two. Weight-loss figures from GLORY-1 and SURMOUNT-1 come from different populations, durations and BMI criteria and cannot rank the drugs.
"Research-grade" mazdutide sold online is the same as the approved medicine
Not supportedNo mazdutide product is FDA-approved; the Chinese approval does not cover U.S. sales.
Online "research" products have no verified identity, purity or sterility. FDA has warned companies selling unapproved mazdutide this way.
Evidence Strength Across Clinical Domains
Inside Peptides evaluates scientific certainty at the claim level. Because clinical evidence varies significantly depending on the therapeutic endpoint evaluated, each domain is assessed independently.
Weight reduction in adults with obesity
Mazdutide: Phase 3 in Chinese adults plus a small U.S. Phase 2. Tirzepatide: multinational Phase 3 and a direct trial versus semaglutide.
Blood glucose in type 2 diabetes
Mazdutide has Phase 3 data versus placebo and dulaglutide in Chinese adults; tirzepatide has the multinational SURPASS program.
Cardiovascular outcomes
Tirzepatide was noninferior to dulaglutide in SURPASS-CVOT; no mazdutide outcomes trial has been published.
Direct comparison between the two
No published head-to-head trial.
What Research Still Doesn’t Tell Us
Identifying open scientific questions, pending active-comparator trials, and areas where long-term clinical data remain incomplete.
A direct randomized comparison
Only a head-to-head trial with the same population, duration and endpoints could show whether either drug produces more weight loss or better tolerability.
Mazdutide outside China
Most Phase 3 data come from Chinese adults with Chinese BMI cut-offs; the U.S. evidence is a single 179-person Phase 2 trial.
Long-term safety and outcomes for mazdutide
Published trials last up to 48 weeks. Cardiovascular, kidney and long-term safety outcomes are not yet known.
Industry funding
The mazdutide trials were funded by Innovent or Eli Lilly, and the tirzepatide trials by Eli Lilly. Independent replication is limited.
Related Compound Profiles
Individual profiles provide full molecular datasheets, CAS numbers, preclinical histories, and compound monographs.
Related Educational Resources
Scientific & Regulatory References
Every pharmacological mechanism, clinical trial result, and regulatory approval cited on this page is traceable to official FDA prescribing documentation, ClinicalTrials.gov registries, or peer-reviewed medical publications.
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Randomized controlled trial · Obesity
Once-Weekly Mazdutide in Chinese Adults with Obesity or OverweightGLORY-1: 610 Chinese adults, 48 weeks; funded by Innovent Biologics.
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Randomized controlled trial · Active comparator
Mazdutide versus dulaglutide in Chinese adults with type 2 diabetes731 Chinese adults with type 2 diabetes, 28 weeks.
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Randomized controlled trial · Type 2 diabetes
Mazdutide versus placebo in Chinese adults with type 2 diabetes
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Randomized controlled trial · Phase 2
Efficacy and safety of mazdutide in adults with obesity or overweight: a US-based, multicentre, phase 2, randomised, placebo-controlled clinical trial179 U.S. adults without type 2 diabetes; funded by Eli Lilly.
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Trial registry record
A Study of IBI362 in Participants With Obesity or OverweightGLORY-1 registry record; completed.
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Trial registry record
A Study of LY3305677 Compared With Placebo in Adult Participants With Obesity or OverweightU.S. Phase 2 registry record; completed.
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Company announcement
Innovent Announces Mazdutide, First Dual GCG/GLP-1 Receptor Agonist, Received Approval from China's NMPA for Chronic Weight ManagementCompany press release (June 2025), not an FDA source.
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Company announcement
Innovent Announces Mazdutide Received Approval from China's NMPA for Glycemic Control in Adults with Type 2 DiabetesCompany press release (September 2025), not an FDA source.
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FDA safety communication
FDA's concerns with unapproved GLP-1 drugs used for weight lossNames mazdutide among unapproved drugs sold as "for research purposes". Checked 11 October 2026.
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Randomized controlled trial · Obesity
Tirzepatide Once Weekly for the Treatment of ObesityDouble-blind, 72 weeks, 2,539 adults without diabetes; funded by Eli Lilly.
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Randomized controlled trial · Head-to-head
Tirzepatide versus Semaglutide Once Weekly in Patients with Type 2 DiabetesOpen-label, 40 weeks, 1,879 adults on metformin; funded by Eli Lilly.
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Randomized controlled trial · Head-to-head
Tirzepatide as Compared with Semaglutide for the Treatment of ObesityOpen-label, 72 weeks, 751 adults without diabetes; funded by Eli Lilly.
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Cardiovascular outcomes trial
Cardiovascular Outcomes with Tirzepatide versus Dulaglutide in Type 2 DiabetesActive-comparator noninferiority trial; funded by Eli Lilly.
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Official U.S. prescribing information
Zepbound (tirzepatide) injection, current U.S. labelChecked 11 October 2026.
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Official U.S. prescribing information
Mounjaro (tirzepatide) injection, current U.S. labelChecked 11 October 2026.