Once-Monthly MariTide Shows Promise for Weight Loss
Gerti Tashko, MD
Your Comprehensive Endocrinologist | Board Certified in Lipidology, Hypertension, and Obesity
Obesity continues to challenge health systems worldwide. Many people struggle despite lifestyle changes, and current medications often require weekly injections. A new phase 2 study published in the New England Journal of Medicine in June 2025 introduces a potential advance: maridebart cafraglutide (MariTide), a once-monthly injectable for obesity management.
This medication combines two mechanisms: it stimulates GLP-1 receptors while blocking GIP receptors. Together, these actions reduce appetite, improve metabolism, and support weight loss.
Study Design
Researchers enrolled about 600 adults with obesity, with or without type 2 diabetes. Participants received either MariTide or placebo for 52 weeks. Doses ranged from 140 mg to 420 mg, given every 4 or 8 weeks. Some groups had gradual dose escalation, while others started at full dose.
The primary goal was to measure the percent change in body weight after one year. In people with diabetes, researchers also tracked changes in hemoglobin A1c (HbA1c), an important marker of blood sugar control.
Key Findings
The results were striking:
Obesity-only group
Average weight loss ranged from 12%–16% of body weight.
Placebo group lost just 3%.
Obesity with type 2 diabetes group
Average weight loss ranged from 8%–12%.
Placebo group lost only 2%.
HbA1c dropped by 1.2–1.6 percentage points with MariTide, compared to no change on placebo.
Side effects
Gastrointestinal issues (nausea, vomiting, diarrhea) were most common.
Gradual dose escalation reduced these effects.
No unexpected safety concerns appeared.
Why This Matters
Weekly GLP-1 therapies like semaglutide and tirzepatide already help patients lose weight. A once-monthly option could make long-term adherence easier, especially for those who find frequent injections burdensome.
For people with type 2 diabetes, MariTide not only lowered weight but also improved blood sugar, making it a dual-action therapy.
Patient Examples
To bring these results into real-world focus:
Obesity without diabetes: If a 42-year-old woman with a BMI of 38 were in the trial, then MariTide could have helped her lose close to 15% of her body weight over one year, compared with minimal loss on placebo.
Obesity with type 2 diabetes: If a 55-year-old man with diabetes participated, then he might have achieved a 10% weight reduction and lowered his HbA1c by more than one percentage point.
Gastrointestinal side effects: If a 36-year-old woman received a high dose without escalation, then nausea could occur. With dose escalation, symptoms would likely improve while weight loss continued.
Long-term adherence: If a 49-year-old man had difficulty remembering weekly injections, then a once-monthly option could have supported consistent treatment and meaningful results.
Plateaus and expectations: If a 60-year-old woman with diabetes joined the trial, then even a 9% weight loss might still have lowered her blood pressure and improved daily function.
Summary Table
Looking Ahead
This trial shows MariTide could be a powerful option for weight management, especially for those who prefer monthly injections. While more studies are needed to confirm long-term safety and real-world outcomes, the results add to a growing list of advanced therapies for obesity and diabetes.
At our practice in Montgomery County, Maryland, we provide thoughtful care for weight, metabolism, and related conditions. As an obesity specialist and diabetes specialist, I evaluate new therapies in the broader context of patient health, balancing benefits with safety and individual needs.
References:
Once-Monthly Maridebart Cafraglutide for the Treatment of Obesity — A Phase 2 Trial. Jastreboff AM, Ryan DH, Bays HE, et al. The New England Journal of Medicine. 2025;. doi:10.1056/NEJMoa2504214.
About Dr. Gerti Tashko, MD
Dr. Gerti Tashko, MD, is an endocrinologist in Montgomery County, Maryland. He is uniquely quadruple board-certified in endocrinology, lipidology, hypertension, and obesity medicine. His practice delivers root-cause-focused metabolic and endocrine care, available virtually and in person. He uses advanced diagnostics, personalized nutrition, and preventive medicine to improve long-term health.
