Pfizer and Amgen are developing monthly GLP-1 weight‑loss injections to improve convenience and adherence, potentially replacing weekly injections like Wegovy and Zepbound.

Clinicians stress individual patient needs, noting monthly dosing isn’t universally superior and depends on the patient’s ability to stick to a schedule and tolerate side effects.

Clinical trial updates include Pfizer’s ongoing middle-stage study with 28-week interim results and Amgen’s late-stage MariTide trials, which are exploring less frequent dosing (every other month or quarterly) and potential obesity indications beyond weight loss.

The broader GLP-1 landscape is expanding with tirzepatide and other experimental agents, as monthly dosing seeks a place alongside established obesity and diabetes therapies.

Pfizer’s berobenatide is designed for longer activity by binding to albumin, enabling monthly dosing and showing up to about 12% average body‑weight loss with improved glycemic control in midstage Type 2 diabetes trials.

Amgen’s MariTide uses an antibody approach to extend its presence in the body and also targets the GIP receptor, with midstage results indicating substantial weight loss—up to 20% of body weight over a year—and potential for even less frequent dosing.

Both programs employ gradual dose titration and begin with weekly dosing before transitioning to monthly injections to manage gastrointestinal side effects, which are generally similar to existing GLP-1 therapies.

Experts acknowledge that monthly dosing could boost adherence for some patients and simplify routines, but others may still prefer or require weekly dosing to maintain consistency or manage side effects.