If Wegovy isn't working, you may not be a non-responder at all

The myth: if the scales haven't moved much, the medicine has failed

This is the misconception our prescribers encounter most often. People reach six or eight weeks on 0.5mg or 1.0mg, notice limited progress, and conclude that semaglutide isn't working for them. The problem with that conclusion is timing. The titration schedule for semaglutide exists precisely because the starting doses are tolerability steps, not therapeutic targets. The body hasn't yet reached the dose at which the medicine exerts its full appetite-suppressing effect.

Genuine non-response is defined against the maintenance dose held for an adequate period, not against early titration doses. NICE's appraisal of semaglutide for weight management (TA875) specifically recommends considering discontinuation only if a person achieves less than 5% weight loss after six months at the maintenance dose. That is the clinical benchmark. Anything before that point is not a verdict on the medicine.

A practical check worth doing in under a minute: look at the injection-site rotation record on your prescription record or injection diary. Repeated injecting into scar tissue or lipohypertrophy (the small lumps that can form under the skin from overused sites) reduces absorption significantly and is one of the more common, entirely fixable causes of an apparently flat response. The raised areas some people notice under the skin after injecting are a separate phenomenon, but both point to technique mattering as much as the medicine itself.

What actually causes a weak response to semaglutide

Before a prescriber considers switching or stopping, they will typically look at several contributing factors. Dose is the first. If the titration has stalled below 2.4mg because of gastrointestinal side effects, the person is not on the licensed maintenance dose and has not had a fair trial of the medicine at its full potency.

Adherence to injection timing is another variable. Semaglutide's long half-life means a missed or significantly delayed weekly dose does not erase a week's effect immediately, but a pattern of inconsistency across months flattens the exposure curve. Similarly, dietary composition matters more than most people expect. A sharp rise in ultra-processed food intake, very high in rapidly digested carbohydrate, can partially override the gastric-emptying delay the medicine produces.

Underlying medical factors are worth discussing with a prescriber too. Thyroid dysfunction, certain medications (including corticosteroids and some antipsychotics), and significant psychological stress can all attenuate weight loss in ways that have nothing to do with how well semaglutide is working pharmacologically. If upper abdominal discomfort has led someone to avoid eating properly alongside the medicine, their energy intake may already be low in ways that confound the result.

The NHS medicines page for semaglutide is a reliable starting point for understanding the medicine's mechanism and what to expect during titration.

When switching to tirzepatide is a legitimate option

For people who have genuinely completed a fair course of semaglutide at 2.4mg and whose weight loss falls short of 5% after six months, switching to tirzepatide (Mounjaro) is a clinically reasonable next step to discuss. The two medicines work differently: tirzepatide activates both GIP and GLP-1 receptors, whereas semaglutide targets GLP-1 alone. That dual mechanism appears to produce meaningfully greater weight loss in many people.

In the SURMOUNT-5 trial, a direct comparison published in the New England Journal of Medicine in 2025, tirzepatide produced greater average weight reduction than semaglutide 2.4mg over 72 weeks in adults with obesity but without diabetes. This does not mean tirzepatide works for everyone, but it does mean that a poor response to semaglutide is not evidence that all GLP-1-class medicines will fail.

A switch requires clinical review, not just a change of prescription. A prescriber needs to assess the reason for switching, confirm eligibility for tirzepatide, and determine the appropriate starting point. Anyone considering this can read a fuller overview of weight-loss treatment options before speaking to a clinician. For context on how private treatment is priced, Wegovy pricing in the UK covers what to expect, alongside what a single transparent fee actually includes.

It is also worth knowing that compounded or unlicensed semaglutide is a separate matter entirely, not an equivalent alternative and not something regulated in the same way as licensed Wegovy pens.

What to do if you think you are not responding

Don't stop injecting unilaterally. That sounds obvious, but stopping abruptly without a plan typically means regaining weight relatively quickly, losing any metabolic adaptations that have developed, and having a harder conversation with a prescriber later.

Contact your prescribing service. A good service will review your dose history, ask about injection technique, look at any side effects that may have prevented adequate titration, and consider blood tests or other investigations if an underlying cause seems plausible. At nume, that review is handled by a clinically experienced prescribing team, not automated decision-making, and every repeat order triggers a fresh clinical assessment rather than a rubber stamp.

If there are unusual symptoms alongside your weak response, those should be mentioned explicitly. And if you have questions before starting that process, the FAQs cover a range of common concerns, or you can reach the team directly via the contact page.

The honest answer is that some people do respond less well to semaglutide than others, and the reasons are biological as much as behavioural. That's not a failure. It's a clinical finding that opens the door to trying something more suited to your physiology. Check your eligibility with our prescribers if you want to explore what that next step might look like for you.