What to Expect from Wegovy After 4 Weeks

Step 1: What your body is doing in the first four weeks

Semaglutide, the medicine in Wegovy, works by activating GLP-1 receptors involved in appetite signalling and the speed at which your stomach empties. At 0.25 mg (the dose for weeks one to four) the primary goal is tolerability, not maximum effect. Your system is learning to work alongside a new hormonal signal, and that takes a little time.

For most people, this means the first fortnight can feel unsettled. Nausea after injecting, a quicker sense of fullness, and some digestive unpredictability are all common early on. By the end of week four, those symptoms have usually softened for the majority of patients, though they don't disappear entirely for everyone. The NHS medicines page for semaglutide lists the full side-effect profile and explains which symptoms warrant a call to your prescriber.

Weight loss at this stage is real but modest. Your appetite is beginning to reduce, portions feel smaller naturally, and food noise (the constant mental chatter about eating) tends to quieten for many people. But the scale may not reflect this yet, partly because the dose is low and partly because body weight fluctuates day to day. That can feel frustrating. It helps to know that the first pen's job is adjustment, not transformation.

Step 2: The dose increase at week four, what changes and why it matters

Week four is when most people move from 0.25 mg to 0.5 mg. This step is part of the licensed titration schedule, moving up in stages rather than all at once reduces the chance of severe GI symptoms and gives your body time to adapt at each level.

The shift to 0.5 mg tends to bring a clearer appetite effect for most people. Hunger between meals drops more noticeably, and the sense of satisfaction from smaller portions often becomes more consistent. Some people also notice mild nausea returning briefly after a dose increase, this usually settles within a week or two, just as it did when treatment began.

It's worth reading about what the first couple of weeks on Wegovy looked like compared with where you are now; many people find the early discomfort feels distant by the time they reach the month mark, which is a useful signal that their body has adjusted well. If you are in any doubt about your timing, your prescriber is the right person to ask, never adjust a dose based on forum posts or general advice.

The broader titration pathway eventually leads up to 2.4 mg, and now, for eligible patients, to a 7.2 mg maintenance dose following the MHRA's approval of a dedicated single-dose pen in April 2026. Those higher doses are several months away for someone starting today; the four-week mark is simply the first step along that schedule.

Step 3: What progress looks like (and what to watch for

In the STEP 1 clinical trial (2.4 mg semaglutide, 68 weeks), participants lost an average of around 15% of their body weight) published in the New England Journal of Medicine. That figure accumulates over more than a year, not a month. At four weeks, a loss of one to three kilograms would be a reasonable range for many people, though some lose a little more and some less.

What matters more at this stage than the number on the scales: are GI side effects manageable? Is appetite beginning to shift? Can you eat at roughly the right portions without fighting yourself? A yes to most of those is a good sign that treatment is working as intended, even if weight loss feels slow.

There are symptoms that should prompt contact with your prescriber or, if severe, urgent medical attention. Persistent, severe stomach pain that spreads to your back (with or without vomiting) should never be ignored, as it can be a sign of pancreatitis. The MHRA highlighted acute pancreatitis as a known risk with GLP-1 medicines in a safety update earlier this year; the Yellow Card scheme is the right place to report any unexpected symptoms. Gallbladder symptoms, signs of dehydration after prolonged vomiting, or any allergic reaction also warrant prompt attention.

If you are thinking about what comes next (including what happens around the six-week point as the new dose beds in) it helps to keep a brief record of your weight and any symptoms so that your prescriber has a clear picture at each review, and reading about what three weeks on Wegovy typically looks like can give you a useful reference point for how your own experience compares. Some people find keeping a note on their phone while the kettle boils each morning makes that easy to stay on top of.

For anyone who has had to stop and is thinking about restarting Wegovy after a break of around four weeks, the restart process is different from a standard dose increase and should always be discussed with a prescriber first. You can also read more about the semaglutide evidence base if you want a fuller picture of how the medicine works over time, or explore weight-loss treatment options to understand how Wegovy fits alongside other approaches.

If you have not yet started and are weighing up your options, the weight-loss treatment overview is a good place to begin. Wegovy is a prescription-only medicine; a prescriber assesses your full history before any treatment is approved. At nume, that review is carried out the same day by a real GPhC-registered prescriber (not software) so you are not waiting days for a response when a question arises.