Semaglutide and visceral fat reduction: what the percentage figures actually mean

What the trial data says about visceral fat loss on semaglutide

The STEP 1 trial is the clearest starting point. Over 68 weeks, adults with obesity who took semaglutide 2.4mg lost an average of roughly 15% of body weight versus around 2.4% on placebo, as reported in the New England Journal of Medicine. What that headline figure doesn't capture is the composition of the weight lost. MRI sub-studies nested within the broader STEP programme found that visceral adipose tissue fell by a considerably larger proportion than total fat mass, with some analyses reporting reductions of 30–40% in visceral fat volume relative to baseline, roughly twice the percentage reduction seen in subcutaneous fat depots over the same period.

Why does that distinction matter? Visceral fat is metabolically distinct. It sits in close proximity to the liver and releases inflammatory cytokines and free fatty acids directly into the portal circulation. Reducing it has outsized effects on insulin sensitivity, blood lipids and markers of cardiovascular risk. Semaglutide's impact on high-sensitivity C-reactive protein tracks with these visceral-fat reductions, and our page covering how semaglutide affects hsCRP reduction percentages points to a benefit that goes beyond the number on the scales.

It is worth holding these figures carefully. Trial participants followed structured diet and activity programmes alongside treatment. The percentage reductions reported come from specific imaging protocols and may not map exactly onto what any individual experiences in clinical practice.

Why visceral fat responds differently to semaglutide than subcutaneous fat does

GLP-1 receptors are expressed not only in the gut and pancreas but also in adipose tissue and the central nervous system. When semaglutide activates these receptors, it reduces energy intake primarily through appetite suppression, but the resulting calorie deficit does not draw equally from all fat compartments. Research consistently shows that high-calorie-deficit interventions mobilise visceral fat preferentially, and GLP-1 receptor agonists appear to amplify this effect beyond what diet alone produces, possibly through direct actions on adipocyte lipolysis and hepatic fat metabolism.

This is one reason clinicians and researchers are increasingly interested in semaglutide as a tool for reducing visceral adiposity specifically, rather than treating weight loss as a single undifferentiated outcome. The SELECT trial, which enrolled adults with established cardiovascular disease and no diabetes, found that semaglutide significantly reduced the risk of major adverse cardiovascular events, and that effect emerged well before the full weight-loss trajectory was complete, hinting at mechanisms that include but extend beyond fat mass alone. You can read more about that outcome data on our SELECT trial results page.

For anyone weighing up treatment options, the NHS semaglutide medicines page provides a reliable plain-English overview of how the medicine works and what to expect.

What this means for people considering semaglutide in practice

The visceral fat figures are compelling, but they sit within a broader clinical picture. Semaglutide 2.4mg is licensed in the UK for adults with a BMI of 30 or above, or 27 or above alongside at least one weight-related condition such as hypertension, dyslipidaemia or type 2 diabetes. Lower BMI thresholds apply for some ethnic backgrounds under UK guidance. NHS access remains phased and subject to strict criteria; for many people, a private prescription through a regulated service is the practical route.

If you are curious about Wegovy's specific effects on visceral fat, or want to compare the full evidence base, our dedicated pages go deeper on both topics. For context on what private treatment costs, the Wegovy price comparison page explains what legitimate UK pricing looks like and what a transparent service includes. That said, price is rarely the most useful frame for evaluating a prescription medicine, clinical suitability comes first, always.

One practical note: orders placed before 12pm on a working day are reviewed the same day by a prescriber and, if approved, dispatched for next-working-day DPD delivery. So whether you're planning around a busy week or your next payday, the timeline is predictable. To explore whether semaglutide is appropriate for your situation, speak to our prescribers through a free consultation, a real clinician reads your answers, not software.