Inside Story

In the same way weight varies from person to person, so do the best weight loss strategies. While some people succeed with diet and exercise alone, others find that adding weight loss medications like Ozempic, Wegovy or Zepbound helps them stay on track with their goals.

But while Semaglutide and tirzepatide are effective, many people struggle to get access and adhere to the once-weekly injections.

Now, as Woman’s World reports, biopharmaceutical company Amgen has been developing a new weight loss drug called MariTide that only needs to be administered once a month. A less-frequent injection could make it easier for patients to stick with their GLP-1, reducing barriers and boosting long-term health outcomes.

But does it work? Actually, according to results from a phase 2 clinical trial posted on June 23, it’s looking very promising. People with obesity who took the drug lost up to 16% of their body weight over 52 weeks. Among participants with both obesity and type 2 diabetes, MariTide led to both weight loss and improvements in glycated hemoglobin (HbA1C) levels, too.

Here’s everything you need to know about the new GLP-1 receptor agonist.

What is MariTide, and how does it support weight loss?

“MariTide is a GLP-1 agonist like semaglutide (Wegovy) and tirzepatide (Zepbound),” explains Evan Nadler, MD, MBA, Co-founder of ProCare Consultants and ProCare TeleHealth. MariTide works like other weight-loss drugs by mimicking a hormone called GLP-1, which helps people feel full, he notes. But what makes MariTide different is how it interacts with another hormone called GIP, which plays a role in regulating blood sugar levels. 

While the drug Zepbound, for example, activates GIP to support weight loss, MariTide actually blocks the GIP receptors. Both methods seem to help people lose weight. This suggests that increasing or decreasing GIP may both enhance how well GLP-1-based drugs work, which Dr. Nadler says is unexpected.

What we know about weight loss with MariTide so far

Maridebart cafraglutide (being referred to as MariTide) completed phase 2 of its clinical trial in November 2024. Full findings from phases 1 and 2 of the clinical trial were presented on June 23, 2025 at the American Diabetes Association’s 85th Scientific Sessions in Chicago. Here’s the rundown….

It’s a once-a-month injection

What sets this new medication apart, is that MariTide also contains a “peptide-antibody conjugate molecule,” which extends the drug’s effects. As such, it can be administered once a month. If you’ve hesitated to try GLP-1 medications like Ozempic because they require weekly injections, MariTide may be a better fit. According to findings published in The New England Journal of Medicine, participants in the phase 2 trial were given MariTide just once a month.

“Patients may find it easier to [keep up] with monthly injections instead of weekly injections,” says Jennifer Brown, MD, ABOM, ABFM, Board-certified Obesity Medicine doctor at MyObesityTeam. “The GLP-1 type injections all must be refrigerated, making them inconvenient at times. Diabetic patients often take multiple daily insulin injections, so any medication that reduces their total number of shots is beneficial. Plus, no one wants to take extra shots if they can avoid it.”

It’s could deliver major health wins

According to Amgen, results from phase 2 trials revealed that MariTide helped study participants (who were living with obesity but did not have diabetes) lose up to 20 percent of their weight on average at 52 weeks—without hitting a weight loss plateau. Experts say these results are significant.

“Twenty percent total-body weight loss is significant, as most people need about 10 percent total body weight loss to start to reverse their weight-related medical problems,” says Dr. Brown. “Of note, the 20 percent threshold is used for bariatric surgery as a cut-off, too, so it’s an important number. Most experts will say that weight loss less than 20 percent after bariatric surgery defines a ‘non-responder,’ or insufficient weight loss from the procedure.”

Amgen phase 2 study results also resulted in up to about 17 percent average weight loss and a reduction in HbA1c (average glucose over three months) up to 2.2 points among trial participants living with both obesity and type 2 diabetes. 

“A drop of 2.2 percentage points for people with type 2 diabetes is very significant and in the same range as the other GLP-1 agonists,” says Dr. Nadler. “The way those numbers are measured in clinical trials can vary based on the average A1C of the study participants, but in general that type of drop can get people under the A1C cut off for diabetes, which is under 6.5 percent.”

However, even with MariTide’s seemingly promising health impacts, users could still experience side effects.  “MariTide and all of the GLP-1 medications have similar side effect profiles: nausea, vomiting, abdominal pain, constipation and less commonly pancreatic irritation,” says Dr. Nadler. “They are usually dose-related—the higher the GLP-1 dose, the more common the side effects. It’s too early to know if the side effects last longer due to the monthly administration of MariTide, but that possibility is concerning, as there are lots of people who stop their weekly injections due to side effects.”

What’s next for Amgen’s MariTide weight loss drug

MariTide’s phase 3 clinical trials are underway and actively enrolling participants, but FDA approval is still needed before the drug can be released to the public. Experts say the available research suggests that the drug has promising potential. “MariTide is expected to be just as safe and effective for those with obesity without diabetes,” says Dr. Brown.

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