Wegovy 4 month results: what does the evidence say at week 16?

Month four sits inside the dose ladder, not beyond it

A question our prescribers hear most weeks is some version of: "I'm four months in and I haven't lost as much as I expected, is something wrong?" The honest answer is that month four is not a finishing line; it is often still the climb. Wegovy's titration schedule runs from 0.25mg up through 0.5mg, 1.0mg, 1.7mg and then to the 2.4mg maintenance dose, with roughly four weeks at each level. That means some people do not reach 2.4mg until week 16 or later, depending on how each step is tolerated.

What this means practically: at month four your appetite suppression may still be strengthening. Comparing your results at week 16 against the headline trial figure of around 15% average loss over 68 weeks is comparing apples to a very different timeline. The STEP 1 trial ran for 68 weeks; the steepest weight-loss curve tends to emerge after the maintenance dose is settled. Progress at four months is real progress. It just is not the whole story yet.

For a broader look at how the timeline unfolds, our page on how long Wegovy takes to work covers the full arc from week one onward.

What the numbers typically look like at this stage

Trial data does not report a single tidy "four-month figure", but working from published STEP 1 curves, weight loss of around 8–12% of starting body weight is a reasonable expectation for participants adherent to the titration schedule at week 16. Some people are below that range; others are above it. A person starting at 100kg might have lost 8–12kg. A person starting at 130kg might have lost proportionally similar weight in percentage terms but a larger absolute number on the scales.

The newer 7.2mg maintenance dose approved by the MHRA in January 2026 is not typically reached at month four, so these figures reflect the 2.4mg pathway. Our Wegovy overview covers the full licensed dose range and what the approval of 7.2mg means for people further along in treatment.

Early months also tend to show faster percentage loss simply because the body is responding to a novel signal. Loss tends to slow later even as total weight lost continues to rise, and our page on Wegovy 2 month results explains what that earlier phase typically looks like before the pattern shifts. This is normal and expected, not a sign the medicine has stopped working.

Why results differ so much between individuals

Genetics play a larger role in GLP-1 response than most people realise. Some people are biologically more sensitive to semaglutide's appetite-suppressing effect; others need more time or a higher dose. Beyond biology, the things that genuinely move the needle at month four include protein intake (preserving muscle while losing fat), consistent physical activity, sleep quality, and how smoothly the titration has gone.

If dose increases have had to be paused because of side effects, the four-month picture will look different from someone who tolerated each step without difficulty. That is not failure; that is the medicine being managed safely. Pushing through significant nausea is not the right approach, and a prescriber can advise on whether to slow the titration, adjust timing or manage symptoms. Side effects after a dose step (nausea, looser stools, reduced appetite to the point of skipping meals) are common and typically settle within one to two weeks, as NHS guidance on semaglutide confirms.

Cost context is relevant here too: if you are considering whether the investment makes sense given your month-four progress, our page on Wegovy costs sets out what an all-in private prescription typically includes and why price-per-pen comparisons can miss the point.

What to do if month four feels slow

The decision this keyword is really asking about is: do I continue, adjust, or question whether this treatment is working for me? A few things are worth separating out before drawing conclusions.

First, check the baseline. How much did you lose in the first month and by month three? A gradual, steady trend is more predictable than a dramatic early drop that then stalls. Second, consider whether you have yet reached your full maintenance dose. If you have not, month four is not a fair test. Third, ask your prescriber. The licensed guidance, referenced in NICE's appraisal of semaglutide (TA875), notes that continuing treatment should be reviewed if less than 5% weight loss is achieved after six months on the maintenance dose. Month four is before that review point.

If you are not yet on Wegovy but are weighing up whether to start, a free consultation with our prescribers is the right first step. A clinician will review your full health picture the same day (not software, not a form that auto-approves) and decide whether semaglutide or an alternative is the right fit.