Main Research Findings

1) Treatment with Mazdutide was shown to reduce cognitive dysfunction associated with type 2 diabetes mellitus.

2) When administered to patients with type 2 diabetes mellitus, Mazdutide was found to significantly improve body weight and HbA1C levels.

Selected Data

1) This study conducted by researchers Dong et al investigated the effects of Mazdutide, a dual GLP-1 and glucagon receptor agonist, on type 2 diabetes mellitus (T2DM) and associated cognitive decline using db/db mice as an experimental model. Mazdutide was administered at three escalating doses of 50 μg/kg, defined as the low dose, 100 μg/kg as a medium dose, and 200 μg/kg as the high dose. Dulaglutide, a GLP-1 receptor agonist, was used at 200 μg/kg as a positive control. All treatments were administered subcutaneously once every three days in a standardized volume of 0.5 mL per mouse [1].
Male db/db mice, which replicate the major features of human diabetes-associated cognitive dysfunction such as hyperglycemia, insulin resistance, and neurodegeneration, were chosen as the experimental animals, while age-matched non-diabetic heterozygote littermates (db/+) served as healthy controls. Only males were used to avoid variability due to hormonal fluctuations in females. The mice were housed in controlled environmental conditions with constant temperature, humidity, and light–dark cycles. They were provided unrestricted access to food and water. Sample size estimation was based on preliminary data from Morris water maze testing, and power analysis indicated that 13 mice per group would ensure sufficient statistical power while accounting for potential attrition. After a two-week acclimation period, the animals were randomly allocated into six groups: db/m normal control, db/db model, three Mazdutide treatment groups for low, medium, high doses, and the dulaglutide group. Treatments were continued for 12 weeks, and all animals were monitored daily with predefined humane endpoints. No animals were lost during the study, and all completed the full protocol [1].
Throughout the experimental period, blood glucose levels, body weights, food and water intake were closely monitored. Behavioral tests were conducted in a consistent order to minimize confounding, and assessments were performed by personnel blinded to group assignment. Following behavioral evaluation, animals were humanely euthanized, and brain tissue samples were collected for histological, transcriptomic, proteomic, and metabolomic analyses.
A battery of behavioral tests was used to assess cognitive and motor function. The open field test measured locomotor activity and exploratory behavior in a novel environment, recording total distance traveled, entries into the center zone, and time spent in the center. The Morris water maze was used to assess spatial learning and memory over five days of place navigation training, followed by a probe trial on day six in which the platform was removed. Measures included latency to platform, number of platform crossings, and time spent in the target quadrant. Reversal learning was also performed by relocating the platform to the opposite quadrant to assess cognitive flexibility [1].
Additional tasks included the Y-maze, which evaluated short-term memory by measuring spontaneous alternation behavior; the novel object recognition test, which assessed recognition memory based on preference for novel objects; and the light–dark box test, which gauged exploratory behavior and anxiety-like responses. Motor coordination was evaluated using multiple assays. The beam-walking test measured balance and hindlimb coordination by recording latency to traverse beams and number of slips. The rotarod test assessed balance and endurance by measuring latency to fall from an accelerating rotating rod. These diverse behavioral paradigms provided a comprehensive assessment of cognitive and motor performance under different treatment conditions [1].
Histological and staining techniques were employed to assess brain structure and pathology. Hematoxylin and eosin (H&E) staining provided a general overview of brain morphology, while Nissl staining detected neuronal damage by visualizing Nissl bodies in hippocampal neurons. Luxol fast blue staining was performed to evaluate myelination in the corpus callosum and spinal cord. Immunohistochemistry was used to assess specific neuronal and glial markers, including NeuN for neuronal nuclei, MAP2 for dendrites, and MBP for myelin. Quantification was performed using image analysis software. Golgi–Cox staining enabled detailed morphological assessment of hippocampal pyramidal neurons, including dendritic length, branching, and spine density, which are key indicators of synaptic plasticity.
At the molecular level, RT-qPCR was used to quantify gene expression changes in brain tissue. RNA was extracted, reverse transcribed into cDNA, and amplified with SYBR-based real-time PCR. Relative mRNA levels were calculated and primers were chosen based on prior validated studies. Transcriptomic profiling using RNA sequencing to provide a broader view of gene expression changes. High-quality RNA was sequenced, aligned to a reference genome, and analyzed for differential expression and functional pathway enrichment [1].
Proteomic analysis was performed using data-independent acquisition mass spectrometry. Proteins were extracted, digested, and separated via chromatography before mass spectrometric analysis. The data were searched against protein databases, with strict false discovery rate thresholds applied. Differentially expressed proteins were identified, and pathway enrichment analysis was performed, and protein–protein interaction networks were constructed to better understand functional relationships. Missing data in proteomics were handled carefully, with low-abundance proteins imputed using conservative methods [1].
Finally, metabolomic profiling was carried out using liquid chromatography–mass spectrometry (LC/MS). Brain samples were analyzed under both positive and negative electrospray ionization modes. Strict quality control was maintained by repeatedly analyzing pooled quality control samples throughout the runs. Data were processed and metabolites were identified by comparison with reference libraries of standards. Functional interpretation was achieved through pathway analysis of differentially expressed metabolites.
In summary, this experimental design combined behavioral testing, histological evaluation, and multi-omics analyses to investigate the therapeutic effects of Mazdutide on diabetes-associated cognitive dysfunction in db/db mice. The design featuring multiple treatment groups, standardized conditions, blinded behavioral testing, and integrated molecular analyses ensured robust and reproducible results. The study not only assessed behavioral outcomes such as spatial learning, recognition memory, and motor coordination but also provided insight into the structural, molecular, and metabolic changes underlying these effects, to create a preclinical evaluation of Mazdutide’s potential benefits [1].
2) This trial performed by Zhang et al was designed as a randomized, double-blind, placebo-controlled, and active-referenced study to assess the efficacy of Mazdutide, a novel therapeutic for type 2 diabetes, compared against placebo and dulaglutide. The study included a 1-week screening period, a 2-week lead-in phase, a 20-week treatment period, and a 4-week safety follow-up. Eligible participants were adults aged 18 to 75 years who had type 2 diabetes for at least six months and demonstrated inadequate glycemic control through diet, exercise, or stable metformin therapy. Inclusion required HbA1c levels between 7.0% and 10.5%, BMI between 20 and 40 kg/m², and stable body weight during the preceding 12 weeks. Participants were expected to maintain consistent diet and exercise routines throughout the study [2].
Participants were randomized in a 1:1:1:1:1 ratio to receive either 3 mg Mazdutide, 4.5 mg Mazdutide, 6 mg Mazdutide, open-label dulaglutide at 1.5 mg, or placebo. Randomization was stratified based on metformin use, and the allocation sequence was generated independently. Mazdutide and placebo were indistinguishable in appearance, ensuring blinding of participants, investigators, and study personnel, except in the dulaglutide group. All treatments were administered via once-weekly subcutaneous injection. Mazdutide dosing followed a stepwise escalation schedule to minimize tolerability issues, with final doses of 3, 4.5, or 6 mg reached by week 9 [2].
Study visits occurred at baseline and multiple points throughout the 24-week duration, including frequent assessments during dose escalation. At each visit, safety parameters such as body weight, vital signs, ECG, and adverse events were recorded. Waist circumference was measured regularly, while blood glucose monitoring, HbA1c testing, and laboratory parameters such as liver enzymes and lipid panels were conducted at specific intervals. A mixed-meal tolerance test was performed at baseline and week 20 to assess postprandial glucose response. Pharmacodynamic measures included fasting glucose, insulin, and C-peptide, while immunogenicity testing monitored for antidrug and
The primary outcome of the study was the change in HbA1c from baseline to week 20, analyzed in the modified intent-to-treat population, which included all patients who received at least one dose of study medication and had evaluable HbA1c data. Secondary efficacy outcomes included the proportion of participants reaching HbA1c targets of <7.0%, ≤6.5%, and <5.7%, as well as changes in fasting plasma glucose, postprandial glucose from the MMTT, and self-monitored 7-point glucose profiles.
Additional secondary endpoints evaluated changes in body weight, waist circumference, and BMI. The trial also assessed the proportion of participants achieving weight loss of ≥5% and the combined outcome of HbA1c <7.0% plus ≥5% weight loss at week 20. Changes in blood pressure, lipid profiles, serum uric acid, and liver enzyme levels were also examined. Post hoc analysis included the proportion achieving ≥10% weight loss. Pharmacodynamic endpoints focused on changes in fasting glucose, insulin, and C-peptide. [2]
Overall, this trial evaluated the efficacy and safety of different doses of Mazdutide compared with placebo and dulaglutide in individuals with inadequately controlled type 2 diabetes, with a primary focus on HbA1c reduction and secondary emphasis on weight loss, and glycemic measures [2].

Discussion
1) The study performed by Dong et al investigated the effects of Mazdutide on metabolic, cognitive, and neurological outcomes in db/db mice, a model of T2DM and obesity. The first focus was on body weight and food intake. Eight-week-old db/db mice were treated for 12 weeks with subcutaneous doses of Mazdutide of 50, 100, or 200 μg/kg, or 200 μg/kg of dulaglutide administered every three days. Mazdutide produced dose-dependent reductions in body weight compared with saline-treated db/db controls. Saline-treated mice gained 36.03% body weight over 12 weeks, whereas Mazdutide-treated mice gained 25.18% with the low dose, 0.25% with the medium dose, or lost 18.27% with the high dose, with high-dose Mazdutide showing significantly greater weight reduction than dulaglutide. All Mazdutide doses and dulaglutide robustly suppressed food and water intake, with the effect being dose-dependent and most pronounced for the high-dose Mazdutide group. Reductions in food intake were evident immediately within 24 hours, sustained over one week, and maintained throughout the 12-week treatment period, with corresponding decreases in water consumption [1].
Mazdutide also improved glycemic control in db/db mice. Both Mazdutide and dulaglutide reduced fasting blood glucose levels for up to 12 weeks. Although early reductions were partially attributable to decreased food intake, glucose levels stabilized at significantly lower levels in treated mice compared with saline-treated controls. High-dose Mazdutide produced glucose-lowering effects comparable to dulaglutide. Histological analyses of liver tissue revealed that both drugs decreased hepatic steatosis and inflammation, with dose-dependent improvements observed for Mazdutide. High-dose Mazdutide provided superior hepatic protection relative to dulaglutide.
Behaviorally, Mazdutide enhanced locomotor activity and exploratory behavior. In open-field tests, medium- and high-dose Mazdutide increased total distance traveled, with high-dose treatment producing greater effects than dulaglutide. High-dose Mazdutide also increased central grid activity, percentage of mobility time, number of entries into central areas, and time spent in central zones, suggesting improved exploratory behavior and reduced anxiety, while no significant effects were observed for rearing, grooming, or defecation frequency [1].
Mazdutide also improved learning and memory. In Morris water maze tests, medium- and high-dose Mazdutide shortened escape latency and increased platform crossings and time spent in the target quadrant relative to db/db controls, with high-dose Mazdutide outperforming dulaglutide. Reversal learning and Y-maze tests confirmed dose-dependent improvements in spatial memory and working memory, with high-dose Mazdutide showing the strongest effects [1].
Motor coordination, balance, and anxiety-like behavior were assessed using beam-walking, rotarod, and light-dark box tests. High-dose Mazdutide reduced time to traverse the balance beam, decreased foot slips, and improved latency to fall and speed in rotarod tests, indicating enhanced motor coordination and balance. Anxiety-like behavior was partially ameliorated, as evidenced by increased transitions in the light-dark box, although total time in the lit compartment did not significantly differ between groups.
At the neurological level, Mazdutide protects against hippocampal injury. H&E and Nissl staining revealed that db/db mice exhibited structural damage, neuronal loss, and pyknosis in the CA1, CA3, and dentate gyrus regions. All doses of Mazdutide, particularly high-dose, mitigated these pathological features more effectively than dulaglutide, increasing the number of Nissl-positive neurons. Additionally, Mazdutide improved myelination, as indicated by increased myelin basic protein (MBP) expression in the hippocampus, cortex, and spinal cord. High-dose Mazdutide produced the greatest enhancement of MBP density, suggesting protection against T2DM- and obesity-associated demyelination, which is relevant for motor learning and cognitive function [1].
In summary, Mazdutide demonstrated dose-dependent efficacy in improving metabolic outcomes, including weight loss, reduced food and water intake, and glucose control, while also enhancing cognitive performance, locomotor activity, motor coordination, and anxiety-like behavior in db/db mice. High-dose Mazdutide additionally exhibited superior neuroprotective effects, mitigating hippocampal neuronal injury and promoting myelination relative to dulaglutide. These findings support the potential therapeutic utility of Mazdutide for T2DM, obesity, and associated cognitive and neurological impairments [1].
2) The research team of Zhang et al performed a trial evaluating Mazdutide versus placebo and dulaglutide. Participants had a mean age of 53.5 years, mean baseline BMI of 27.4 kg/m², mean HbA1c of 8.06%, and an average diabetes duration of 4.9 years. Approximately 59% were male, and two-thirds were using metformin at baseline. Thirty participants discontinued study treatment but remained in follow-up, while 14 discontinued the study entirely. Two participants were excluded from the modified intent-to-treat (mITT) population due to lack of postbaseline data, resulting in 248 participants for efficacy analyses. Baseline demographics and characteristics were balanced across groups [2].
In the primary analysis, Mazdutide produced significantly greater HbA1c reductions from baseline to week 20 compared with placebo. Reductions ranged from –1.41% to –1.67% across different Mazdutide doses, compared with –1.35% for dulaglutide and virtually no change with placebo (–0.03%). Estimated treatment differences versus placebo were significant, measuring at -1.44% for 3 mg, -1.70% for 4.5 mg, –1.58% for 6 mg Mazdutide, and –1.38% for dulaglutide. Differences between Mazdutide and dulaglutide were modest, ranging from –0.06% to –0.32%, with 4.5 mg [2].
At week 20, 54–73.5% of Mazdutide-treated participants achieved the HbA1c target of <7.0%, compared with 60% for dulaglutide and only 17.6% for placebo. Similarly, 28–56.3% of those on Mazdutide achieved HbA1c ≤6.5%, compared with 46% for dulaglutide and 7.8% for placebo. Normoglycemia defined as an HbA1c <5.7% was achieved by 6.1–10.4% of participants on Mazdutide, 10% on dulaglutide, and 2% on placebo.
Mazdutide also improved fasting and postprandial glucose control. Reductions in fasting plasma glucose ranged from –1.40 to –2.58 mmol/L with Mazdutide and –2.06 mmol/L with dulaglutide, compared with virtually no change with placebo. Postprandial glucose following mixed-meal tolerance testing and 7-point self-monitored glucose profiles showed consistent improvements with all Mazdutide doses and dulaglutide. Measures of β-cell function improved with Mazdutide and dulaglutide versus placebo, while reductions in fasting insulin and HOMA of insulin resistance were most prominent at the higher Mazdutide doses [2].
In terms of weight loss, Mazdutide produced dose-dependent reductions in body weight, ranging from –4.12% to –7.11% compared with –2.69% for dulaglutide and –1.38% for placebo. The estimated differences versus placebo were –2.74% for 3 mg, –3.92% for 4.5 mg, –5.73% for 6 mg Mazdutide, and –1.31% for dulaglutide. Greater weight loss was associated with greater HbA1c reductions. By week 20, 24–57.1% of participants receiving Mazdutide achieved ≥5% weight loss, compared with 18% with dulaglutide and 9.8% with placebo.
Moreover, 16–49% of mazdutide-treated participants achieved ≥10% weight loss, whereas no participants in the dulaglutide or placebo groups did. A combined outcome of ≥5% weight loss and HbA1c <7.0% was met by 16–49% of Mazdutide participants, compared with 12% with dulaglutide and none with placebo. Waist circumference, blood pressure, and lipid profiles also improved, with the greatest blood pressure reduction observed with 4.5 mg Mazdutide. Dose-dependent reductions in total cholesterol, LDL cholesterol, triglycerides, liver enzymes, and uric acid were also observed. Overall, Mazdutide significantly improved glycemic control, body weight, and cardiometabolic risk markers in a dose-dependent manner compared with placebo, with efficacy comparable to or exceeding dulaglutide [2].

Figure 1: Changes in A) HbA1c levels from baseline, B) number of participants achieving HbA1c target goal, C) fasting plasma glucose levels, D) self-measured blood glucose levels, E) body weight, and F) number of participants achieving weight loss goal, across all 5 experimental treatment groups.

Disclaimer

**LAB USE ONLY**
*This information is for educational purposes only and does not constitute medical advice. THE PRODUCTS DESCRIBED HEREIN ARE FOR RESEARCH USE ONLY. All clinical research must be conducted with oversight from the appropriate Institutional Review Board (IRB). All preclinical research must be conducted with oversight from the appropriate Institutional Animal Care and Use Committee (IACUC) following the guidelines of the Animal Welfare Act (AWA).

Citations

[1] Dong W, Bai J, Yuan Q, et al. Mazdutide, a dual agonist targeting GLP-1R and GCGR, mitigates diabetes-associated cognitive dysfunction: mechanistic insights from multi-omics analysis. EBioMedicine. 2025;117:105791. doi:10.1016/j.ebiom.2025.105791

[2] Zhang B, Cheng Z, Chen J, et al. Efficacy and Safety of Mazdutide in Chinese Patients With Type 2 Diabetes: A Randomized, Double-Blind, Placebo-Controlled Phase 2 Trial. Diabetes Care. 2024;47(1):160-168. doi:10.2337/dc23-1287

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