How much weight can you lose on semaglutide — and what does treatment actually cost in the UK?

The biggest misconception: headline weight-loss figures are averages from ideal trial conditions

The number that circulates most (roughly 15% body weight over about 68 weeks) comes from the STEP 1 phase 3 trial, published in the New England Journal of Medicine. That figure is real and clinically significant. What it is not is a personal guarantee. Trial participants followed structured lifestyle support alongside 2.4mg weekly semaglutide; results at lower maintenance doses were more modest; and a meaningful proportion of participants saw less than the average while others saw considerably more.

There is also a newer option: the MHRA approved a single-dose 7.2mg semaglutide pen (Wegovy) in April 2026, with trial data showing average weight loss of around 20.7% over 72 weeks at that higher dose. That narrows the gap with tirzepatide results considerably. If you want the detailed breakdown by dose and duration, our page on what weight loss to expect on semaglutide covers it properly.

The corrected picture, then: semaglutide produces clinically meaningful weight loss for many people, and if you want to understand how much weight you can lose taking semaglutide across different doses and timeframes, we cover that in detail elsewhere. The exact amount depends on your starting weight, the dose you reach, how long you stay on treatment, and what lifestyle changes you make alongside it. A prescriber, not a website, works that out with you.

What UK private semaglutide actually costs, and what those prices often leave out

UK private weight-loss treatment is priced per pen or per month and varies between providers. Since Eli Lilly's list-price increase for Mounjaro in September 2025 reshaped the market, prices across the sector have shifted; for context on how semaglutide (Wegovy) pricing compares, our Wegovy price guide sets out the current landscape clearly.

What many headline prices leave out is worth knowing before you compare. Consultation fees are sometimes charged separately. Prescription charges, delivery costs, and aftercare support are regularly additional line items at some providers. Dose-review appointments (which should happen before any increase) may carry their own fee. Add those up across a course of treatment and the headline monthly figure can look quite different from the total you actually pay. If you are also wondering whether there is a cheaper version of Wegovy available, our dedicated page explains what the options actually are and what to watch out for.

There are also providers in this space who advertise prices without any real clinical structure behind them. Semaglutide is a prescription-only medicine; the MHRA has warned repeatedly about counterfeit pens sold through social media and websites offering these medicines without a proper prescription or clinical assessment. Prices that sit far below the market norm are a red flag, not a bargain.

What a single, transparent price at nume actually covers

We are not the cheapest option. That is a deliberate choice, not an oversight. What one price at nume covers: your free consultation, clinical review by a GPhC-registered Independent Prescriber, your prescription, your treatment, and free next-working-day tracked delivery. Your pen arrives in plain, unbranded packaging via DPD, you get a tracking link and a time slot, so there is no standing at the door wondering. Aftercare support runs seven days a week, and before any repeat order your case is reviewed by a prescriber again. No subscription, no auto-renewal, no hidden charge waiting at checkout.

You can verify that we are a legitimate, GPhC-registered pharmacy directly on the official register at GPhC registration 9012878. Our clinical team profile is on our prescriber page if you want to know who is reviewing your consultation.

Current treatment pricing is shown on our treatment page, we don't print per-pen figures in editorial copy, because prices can change and we'd rather you see the live, accurate number than a figure that is six weeks out of date.

Why 'cheapest' is the wrong test for a prescription medicine

For a pair of trainers, price comparison makes straightforward sense. For a medicine that requires clinical assessment, titration by a prescriber, and monitoring over months, the cheapest listing answers the wrong question entirely. The right questions are: is this pharmacy on the GPhC register? Is a qualified prescriber reviewing my case, or is it a checkbox form? Is the medicine coming through a licensed UK supply chain?

NICE's appraisal of semaglutide for weight management, TA875, makes clear that this treatment works best within a structured clinical framework, not as a product dispatched without proper assessment. The same logic applies in the private sector. A small saving on the monthly price is not the metric that keeps you safe or gets you the best outcome.

If you are weighing up whether semaglutide or tirzepatide is the better fit for you, or want a personalised sense of how much weight you could lose with semaglutide given your own starting point, our pages on realistic weight loss on semaglutide and weight-loss treatment options go into more depth. When you are ready to talk to a prescriber, the consultation is free and the same-day review means you're not waiting.