Stalling on Wegovy: what the evidence says about weight loss plateaus

What STEP 1 actually tells us about the stall

The STEP 1 trial followed 1,961 adults with obesity over 68 weeks. Average body weight fell by roughly 15% on semaglutide 2.4 mg, compared with about 2.4% on placebo. What the headline figure doesn't show is the shape of that curve. Loss was steepest in weeks four to sixteen. After that, the rate slowed considerably for most participants, and by around week 48, weight had largely plateaued. Participants were still benefiting (holding a significant reduction) but the scale had stopped moving.

That deceleration is not a sign that semaglutide stops being active in the body. The medicine keeps suppressing appetite through the same GLP-1 receptor pathway. What changes is the body's baseline: at a lower weight, your resting energy expenditure decreases, so the same calorie deficit that once produced loss now merely maintains. The trial was designed around 68 weeks, and the plateau was built into the expected outcome, not buried in a footnote.

A common misconception is that a stall means something has gone wrong or that the treatment has failed, and our page on what a Wegovy weight loss stall actually involves explores why the evidence frames things quite differently: reaching a sustained lower weight is the therapeutic outcome, and a plateau is part of getting there. Understanding that distinction matters before deciding any next step.

Factors that can deepen or prolong a stall

Not all plateaus are the same. Some are a natural settling point; others reflect something addressable. The NHS medicines page for semaglutide notes that treatment works best alongside a reduced-calorie diet and increased physical activity, and the evidence bears that out. Several patterns are worth reviewing with your prescriber.

Protein intake tends to fall on GLP-1 treatment because overall appetite is lower. Eating less protein while in a calorie deficit accelerates muscle loss, which further reduces metabolic rate and can entrench a stall. Most adults on weight-loss treatment benefit from consciously prioritising protein within a smaller food volume. Separately, disrupted sleep raises cortisol and ghrelin in ways that blunt the appetite-suppressing effect of semaglutide, a detail that often surprises people, and if you want a closer look at the specific causes, our page on stalled weight loss on Wegovy walks through the most common contributors. And resistance-based exercise, even light, preserves lean mass in a way that walking alone does not.

Stress and ultra-processed food (which bypasses gastric emptying effects that partly drive the medicine's satiety signal) are also worth reviewing. None of this is about willpower. It is physiology, and a clinician can help separate the modifiable factors from the ones that aren't.

Dose, duration and what to do next

Wegovy is titrated by a prescriber from 0.25 mg upward, with 2.4 mg as the standard maintenance dose. In January 2026, the MHRA also approved a 7.2 mg maintenance dose for eligible adults with obesity, reported to produce around 20.7% average weight loss over 72 weeks. If you have not reached 2.4 mg, a plateau at a lower dose may partly reflect that titration is still ongoing rather than any ceiling effect.

If you are weighing up how long to continue treatment, our page on how long you stay on Wegovy covers the clinical thinking behind that question in detail, and questions about how long you can stay on Wegovy are explored in more detail on our duration guidance page, but the short answer is that duration is a clinical decision, not a fixed rule. NICE's recommendation for semaglutide (TA875) notes that treatment is approved for up to two years within a specialist weight management setting; your prescriber reviews whether continuing, adjusting or pausing best fits your circumstances at each stage.

Switching to tirzepatide is another option some prescribers consider. Our treatment overview outlines the licensed medicines available privately in the UK. That is not a decision to make based on a forum post, it requires a full clinical re-assessment, and any legitimate service will insist on one. For context on private treatment costs, our Wegovy price comparison page sets out what an honest, all-inclusive price should cover.

When a plateau might need closer review

Most stalls resolve or stabilise with lifestyle adjustments and, where appropriate, dose optimisation. Some situations do warrant a more careful look. If weight is increasing rather than just not falling, or if side effects have significantly limited how much you can eat without a corresponding loss, your prescriber needs to know. Equally, if you are early in treatment and wondering how long before you start losing weight on Wegovy, or if you have lost less than 5% of body weight after six months at your highest tolerated dose, NICE guidance on both tirzepatide and semaglutide recommends reviewing whether continuing is right for you.

The team at our clinical lead's profile page outlines the kind of clinical oversight we apply at every review. A plateau is not a reason to panic, but it is a reason to make sure your prescriber has a full picture (weight trends, current dose, diet patterns, activity, sleep) so the review is genuinely useful. You can read broader context about how we approach ongoing care on our about page. If you have questions before a formal review, our FAQs cover the most common ones.

If you are considering starting treatment or want a clinical reassessment of where you are, check your eligibility with our prescribers, every consultation is reviewed the same day by a real clinician, not a system.