Does weight impact the dosage of Wegovy needed?

No — Wegovy uses fixed doses, not weight-based dosing. Heavier people don’t automatically receive higher doses, and lighter people aren’t set lower. The goal is simply to find the lowest well-tolerated dose that delivers results within your service’s review framework.

Why Wegovy isn’t weight-based

Unlike medicines that scale by body weight, Wegovy (semaglutide) follows a fixed-dose titration: 0.25 mg → 0.5 mg → 1.0 mg → 1.7 mg → 2.4 mg. NICE TA875 and NHS England’s 2025 guidance confirm that this standard schedule applies across eligible adults. Semaglutide acts on GLP-1 receptors in the gut and brain until these sites are saturated; beyond that point, increasing the dose doesn’t produce proportionally greater effects. Instead, it increases the likelihood of nausea or reflux. STEP clinical trials used the same dose sequence for all participants with BMI ≥30 kg/m² or ≥27 kg/m² with comorbidities — and results were consistent regardless of starting weight.

The pharmacological reasoning

Semaglutide’s weekly schedule depends on its long half-life (about seven days) and stable receptor engagement. Because distribution is based on plasma protein binding rather than body mass, heavier individuals don’t need larger doses to maintain therapeutic levels. NICE, MHRA, and SMC reviews all note that once GLP-1 receptors are fully occupied, metabolic effects plateau. This makes uniform dosing both practical and safe, simplifying treatment across NHS and devolved services.

How clinicians tailor within the framework

Personalisation happens through tolerance and response. Some people stabilise comfortably at 1.7 mg, while others continue to 2.4 mg if side effects are minimal. NHS practice allows temporary “holds” during escalation if nausea or reflux persist. In real-world settings, many clinicians extend each dose step from four to six weeks, mirroring adjustments used in STEP-5 and SELECT follow-up cohorts. NICE TA875 explicitly supports such flexibility as part of “shared decision-making,” focusing on wellbeing rather than speed.

What the evidence shows

Across the STEP programme, semaglutide produced around 15 % average weight loss over 68 weeks. Importantly, this figure was similar across BMI ranges from 30 to over 50 kg/m². SELECT (Lancet 2024) confirmed that cardiovascular benefits, such as reduced heart-attack and stroke risk, also occurred independently of baseline weight. In NHS pilot audits of early prescribing (2024–2025), clinicians observed comparable outcomes between participants weighing 80 kg and those over 140 kg — further validating the fixed-dose approach. These findings underpin current commissioning policy, which bases review decisions on overall progress, not kilograms treated per dose.

Why dose escalation is standardised

The fixed titration ladder allows the body to adapt gradually to slower stomach emptying and appetite changes. MHRA safety guidance shows that people who followed the full step-up sequence had far fewer reports of nausea and vomiting than those who tried to escalate faster. Standardisation also helps pharmacists monitor refills and identify errors quickly — each pen strength is colour-coded, reducing confusion during transitions.

When adjustments are made

Dose modifications relate to side effects or co-medications rather than size. People using insulin or sulphonylureas may need reduced doses of those medicines to prevent low blood sugar. Others with gastrointestinal sensitivity might pause at a lower level until digestion stabilises. NICE guidance allows treatment continuation at 1.7 mg if weight, blood pressure, or metabolic markers improve satisfactorily. In these cases, staying lower is clinically sound, not under-treatment.

Clinical and practice observations

NHS clinicians report that maintaining hydration and higher dietary protein during escalation helps reduce nausea, particularly in heavier individuals with larger appetite adjustments. Some patients have found it helpful to pair their dose increase with a dietitian-guided meal plan or smaller, more frequent meals — advice echoed in NICE’s obesity management guide (2025). Practice audits from Scotland’s SMC pathway also show fewer discontinuations when clinicians spend extra time reviewing side-effect management before increasing to 2.4 mg. These practical steps highlight that success depends more on support and pacing than on total body weight.

What people can expect in review clinics

Routine follow-ups every 16 to 24 weeks assess wellbeing, appetite, and progress. NICE continuation criteria typically expect a 5 % or greater weight reduction after six months, with the same metric applied to all users regardless of starting BMI. NHS clinicians focus on quality-of-life markers — energy, comfort, sleep, and physical function — alongside numbers on the scale. Those meeting improvement thresholds continue at their existing dose rather than pushing higher unnecessarily.

Lessons we can draw

Wegovy dosing isn’t dictated by weight but by response and tolerability. Fixed steps simplify care, reduce side-effect risk, and produce consistent outcomes across body sizes. The evidence from STEP, SELECT, and NHS experience shows that higher doses aren’t inherently better — steady, well-supported progression works best. NICE, NHS, MHRA, and SMC guidance all align on this: effective treatment means finding the dose your body manages comfortably, not matching medicine volume to weight.