How long for Wegovy to work — and what to expect week by week

You've taken your first injection, here's what the next few weeks actually feel like

Picture this: you've just done your first 0.25 mg Wegovy injection. The pen goes back in the fridge, and you wonder whether anything is actually happening. At this stage, the honest answer is: a little, but slowly. The 0.25 mg dose is not where the weight loss happens, its job is to give your gut time to adjust to semaglutide before the dose climbs.

Within the first week or two, many people report that food simply feels less urgent. Hunger between meals quiets down. Portions at dinner are smaller without any real effort. This is the GLP-1 receptor pathway doing its work: slowing gastric emptying and reducing appetite signals in the brain. The scale may barely move at this point, and that is normal. The dose increases roughly every four weeks, and the therapeutic effect builds with it. Some people see modest losses of one to two kilograms in the first month; others see very little until the dose rises. Neither pattern means the medicine is failing.

One misconception worth letting go: that if you haven't lost a stone by week four, it isn't working. Wegovy isn't a fast switch. It's a gradual recalibration of how your body responds to food, and the early weeks are the foundation, not the result. How quickly Wegovy starts working depends partly on starting dose and partly on individual physiology, and both are worth understanding before you judge the timeline.

Months two to four: when most people start to see real progress

By the time the dose reaches 1.0 mg or 1.7 mg, somewhere around weeks eight to sixteen, appetite suppression is more consistent and weight loss usually becomes visible on the scales. This is the phase when people frequently describe eating about half what they used to without feeling deprived, and losing between half a kilogram and one kilogram a week.

For context, the STEP 1 trial (1,961 adults with obesity, 68 weeks, published in the NEJM) showed an average weight reduction of around 15% at the 2.4 mg maintenance dose. That didn't happen in month one. The bulk of the loss in that trial accumulated across the full titration period and into the maintenance phase. Real-world experience tracks fairly closely: a five to ten per cent reduction by around month three to four is a reasonable benchmark for someone responding well.

If progress feels slower than expected, it's worth reviewing the lifestyle piece. Wegovy works alongside a reduced-calorie diet and increased activity, it isn't designed to override poor sleep, high stress or a diet that hasn't shifted at all. Our guide to slow progress on Wegovy covers the common culprits in more detail. Cost is occasionally a factor in whether people stay consistent; for a clear picture of what treatment involves financially, the Wegovy cost page sets it out plainly.

Months five to twelve and beyond: maintenance, plateaus and the NICE six-month review

Once the 2.4 mg maintenance dose is established, most people's weight loss continues, but more slowly than the early months. A plateau is common around month six to eight and doesn't mean progress has stopped permanently. It usually reflects the body settling at a lower defended weight, and it often shifts again with consistency.

The NICE appraisal of semaglutide (TA875) includes a specific checkpoint: if someone hasn't lost at least five per cent of their starting weight after six months at the highest tolerated dose, continuing treatment should be reconsidered. This isn't a punitive threshold, it's a clinical safeguard to make sure the medicine is actually doing something useful for that individual. A prescriber, not the patient, makes that call.

It's also worth understanding that how long Wegovy takes to work for weight loss is a separate question from how quickly it starts, and the evidence suggests weight tends to return when treatment stops, which is why the decision to continue, reduce or stop is a clinical conversation, not a self-managed one. The semaglutide titration schedule and what the maintenance phase looks like are covered thoroughly on the Wegovy treatment overview. For the broader question of how semaglutide timelines compare across formulations, how long semaglutide takes to work addresses the wider picture.

If you're thinking about whether Wegovy is the right fit for you, or whether your current progress makes sense clinically, speaking to a prescriber is the most useful step. Check your eligibility with our prescribers, consultations are free, and a GPhC-registered clinician reviews every application the same day.