Review suggests most GLP-1 users regain weight within two years after stopping

GLP-1 receptor agonists-medications like Ozempic, Wegovy, Mounjaro, and Zepbound—mimic a natural gut hormone that signals fullness to the brain while slowing digestion and boosting insulin release. They've transformed weight loss for millions, with over 15 million Americans now using them. However, obesity is a chronic condition, and the Oxford team wanted to understand what happens when patients stop treatment and how this compares to behavioral approaches like diet counseling and exercise programs.

The researchers systematically reviewed randomized trials and observational studies, pooling data on weight trajectories after treatment cessation. They compared GLP-1 users against participants in lifestyle interventions, tracking regain rates over time. Statistical modeling extrapolated longer-term outcomes based on observed patterns during the first 12 months post-treatment.

Key findings showed rapid weight rebound among GLP-1 users. One year after stopping, many had regained nearly all lost weight—far outpacing the slower regain seen in diet-and-exercise groups. Experts like Adam Collins from the University of Surrey suggest prolonged high-dose GLP-1 exposure may suppress natural hormone production, making overeating more likely once medication stops.

While some long-term projections relied on modeling rather than direct observation, the pattern was clear: drugs alone don't sustain results. Muscle loss during treatment—ranging from 15-60% of total weight lost—further complicates matters, especially for older adults.

Researchers emphasize combining GLP-1 therapy with strength training, nutrition counseling, and behavioral support for lasting success.

REFERENCE: West S, Scragg J, Aveyard P, Oke J L, Willis L, Haffner S J P et al. Weight regain after cessation of medication for weight management: systematic review and meta-analysis BMJ 2026; 392 :e085304 doi:10.1136/bmj-2025-085304