Stopped losing weight on semaglutide? What the evidence says

What trial data actually shows about plateau points

The STEP 1 results are a useful starting point because they show the plateau pattern at a population level. Participants taking semaglutide 2.4mg lost an average of roughly 15% of body weight over 68 weeks, but the rate of loss was not constant throughout. The steepest drop happened in the first 20 weeks. By weeks 48 to 68, the loss curve had flattened considerably for most people, even though they remained on the same dose with no change in lifestyle support.

This matters because it reframes the question. A plateau at month 12 is not the same thing as the medicine failing. What clinical data describes is a convergence: as your body becomes lighter, the calorie deficit needed to lose another kilogram requires proportionally more effort from every mechanism involved, including semaglutide's appetite-suppressing effect. The NHS semaglutide patient information notes that the medicine works alongside a reduced-calorie diet and increased activity precisely because none of these inputs works in isolation.

If your plateau arrived very early (at week two or three) the picture is different. A very short-term flat phase in the first weeks of treatment is almost always about the body adjusting to the starter dose rather than a true stall. Our guide on what happens if semaglutide isn't working in week 2 covers that specific scenario in detail.

Why metabolism fights back as you lose weight

Physiologists call it adaptive thermogenesis. As body weight falls, the body progressively reduces its resting energy expenditure, it burns fewer calories at rest than it did at the same dose when you were heavier. This is not unique to semaglutide; it happens with any weight-loss approach and is the main reason a calorie deficit that produced a steady half-kilogram a week at the start eventually produces less.

Semaglutide blunts appetite and slows gastric emptying, which reduces how much you want to eat. But if your actual calorie intake has unconsciously crept back up (a portion here, the extra coffee with milk you stopped counting) the gap between intake and expenditure narrows, and the scale reflects that. The medicine keeps doing its job; the deficit quietly closes around it.

There is also a dose dimension. If you reached 2.4mg and your prescriber agrees that the maximum approved dose hasn't produced sufficient progress, the newer 7.2mg semaglutide pen, approved by the MHRA on 14 April 2026, is now an option for some patients with a BMI of 30 or above. Whether that is appropriate is a clinical decision made at review, not something to pursue independently. Our guide to how long people stay on Wegovy looks at the longer treatment arc in more detail.

Factors that can turn a temporary plateau into a persistent one

Three things come up most consistently when prescribers review a stall. First, adherence. An injection left in the handbag and not refrigerated properly (the SmPC specifies a limited window at room temperature before a dose is compromised) or doses delayed by more than a day or two can reduce the medicine's effectiveness without the person realising it.

Second, protein and activity. Semaglutide's appetite reduction can cause people to under-eat protein, which accelerates the loss of lean muscle. Less muscle mass means a lower resting metabolic rate, which tightens the plateau further. A dietitian or prescriber reviewing this often identifies a practical fix here.

Third, clinical factors separate from the medicine itself. Thyroid function, sleep quality, certain medications, and hormonal changes can all independently slow weight loss and are worth ruling out if a plateau persists for more than eight to twelve weeks. A review of whether a different approach to treatment might help (including what continuing into week 6 and beyond looks like) is worth requesting if nothing is shifting.

For context on how much private treatment costs if you are weighing whether to continue under a different arrangement, the Wegovy cost overview sets out what to expect.

When a plateau means something needs to change

NICE guidance for semaglutide (TA875) suggests that if someone has not achieved at least 5% weight loss after six months on the maintenance dose, the clinical team should consider whether continuing is appropriate. That is a benchmark worth knowing, but it applies to the maintenance dose specifically, it is not a verdict on earlier dose stages. A plateau at 1.7mg does not mean semaglutide will not work for you at 2.4mg.

The honest answer is that plateaus are almost always worth reviewing before concluding that treatment has failed. Sometimes a single conversation with a prescriber identifies an obvious variable that had been missed. Our broader guide on weight loss stalling on Wegovy covers additional angles, and if you are thinking about the treatment journey overall, the Wegovy treatment overview sets out the full picture. If you would like a clinical review of where you are, you are welcome to check your eligibility with our prescribers.