Why has my weight loss stalled on a GLP-1?

A plateau on a GLP-1 is normal physiology, not a sign the medication has stopped working. Weight loss is fastest in the first six months, slows through the second six, and levels off as energy expenditure falls with body size and the appetite effect reaches its ceiling at a given dose. In STEP 1 the weight curve was largely flat by around week 60 of 68. In SURMOUNT-1 it flattened towards week 72.

The first question is whether you are at an effective dose

Many plateaus are simply an unfinished titration. Tirzepatide has three maintenance doses, 5, 10 and 15 mg, and SURMOUNT-1 showed 16.0 percent, 21.4 percent and 22.5 percent weight loss respectively in the efficacy analysis. Someone stalled at 5 mg has two steps left. For semaglutide the standard maintenance dose is 2.4 mg weekly, and a higher 7.2 mg dose was approved as Wegovy HD in March 2026 after the STEP UP trial showed around 18.7 percent weight loss at 72 weeks, with gastrointestinal side effects in 71 percent of that group against 61 percent at 2.4 mg. More dose means more effect and more symptoms.

What else flattens the curve

Protein intake usually falls when appetite is suppressed, and low protein with no resistance training costs lean mass, which lowers resting energy expenditure. Alcohol returns for many people around month six. Sleep loss raises appetite. Untreated obstructive sleep apnoea, weight-promoting medications and thyroid disease all limit response. So does the ordinary drift of portion sizes once nausea settles and eating becomes comfortable again. Real-world results run below trial results for exactly these reasons: in a Cleveland Clinic cohort of 7,881 adults, one year weight loss averaged 8.7 percent, against 14.9 to 20.9 percent in the phase 3 trials.

When the plateau is actually the destination

The 2026 ADA standards define a sustained loss of 5 percent or more as clinically meaningful and 10 percent or more as the level that manages many obesity-related complications. If you have reached a stable weight with better blood pressure, better glucose, resolved sleep apnoea and a functioning life, continuing to chase the scale may cost more lean mass than it gains you in health. Not every plateau needs breaking.

Take four things to your review appointment: your current dose and how long you have been on it, three days of honest food logging with protein counted, your alcohol intake, and your sleep pattern. Those four resolve most plateaus without any change to the prescription.