Next-generation GLP-1 drugs cut 4.16% of body weight, with vomiting the price

Type 2 diabetes and obesity frequently travel together, and medicines that improve blood sugar control while also reducing body weight are in enormous demand. Mazdutide and cotadutide belong to a newer drug class that activates the glucagon receptor as well as the GLP-1 receptor. Individual trials of these dual agonists have reported results, but a pooled picture of how much glucose control and weight loss they deliver, and at what cost in side effects, has been lacking. This review set out to provide that summary from the randomised, placebo-controlled evidence.

The authors searched Medline, PubMed, Scopus, the Cochrane database and Web of Science up to 5 March 2024 for randomised, placebo-controlled trials of mazdutide and cotadutide in people with type 2 diabetes, obesity or both. Eleven published studies and four unpublished trials were included. The primary outcomes were the change in HbA1c, a standard measure of longer-term blood sugar control, and the percentage change in body weight from each trial's baseline. Safety was assessed through serious adverse events, treatment-emergent adverse events and specific side effects such as vomiting.

Pooled across trials, the dual agonists reduced HbA1c by 0.63 percentage points, fasting plasma glucose by 1.71 mmol/L, and body weight by 4.16% compared with placebo, and all of these effects were highly statistically significant. On safety, serious adverse events were no more common on the drugs than on placebo, with an odds ratio of 1.03. However, treatment-emergent adverse events were significantly more likely, with odds 2.52 times higher. Vomiting stood out most sharply, with odds 6.05 times higher than placebo.

These results position mazdutide and cotadutide as genuinely effective for both glycaemic control and weight reduction, which supports the dual-agonist approach as a next step in this drug family. What the analysis cannot say is how these drugs compare head to head with the GLP-1 medicines already in wide use, since the included trials were placebo-controlled rather than drug-versus-drug. The inclusion of four unpublished trials broadens coverage but means some data have not passed peer review. Longer-term questions, including durability of the weight loss and safety beyond the trial periods, remain open.

If you follow the fast-moving world of weight and diabetes medication, this is a useful preview of the next wave: drugs adding glucagon receptor activity to the familiar GLP-1 action, with measurable weight and blood sugar improvements in trials. It is equally a reminder that gut side effects, vomiting in particular, are the recurring price of this drug family. Serious harm did not rise in the pooled data, which is reassuring as far as the trial periods run. Anyone weighing such medication would be balancing benefit against tolerability with a clinician, not a headline.