Medicines Similar to Semaglutide: What the Evidence Actually Shows

What the trial evidence tells us about semaglutide and tirzepatide side by side

The clearest picture of how these medicines compare comes from SURMOUNT-5, a head-to-head trial published in the New England Journal of Medicine (2025) that randomised 751 adults with obesity and no diabetes to tirzepatide or semaglutide 2.4mg for 72 weeks. Tirzepatide produced greater average body-weight reduction across the trial period. That result informed NICE's appraisal of tirzepatide (TA1026), published December 2024, which noted the indirect comparisons also favoured tirzepatide.

Semaglutide 2.4mg, the standard Wegovy maintenance dose, averaged around 15% body-weight loss over 68 weeks in the STEP 1 trial. Tirzepatide reached approximately 20–21% at its highest dose in SURMOUNT-1. These are averages from thousands of trial participants; individual results vary considerably, and neither figure applies to everyone.

The newer Wegovy 7.2mg dose, approved by the MHRA in January 2026 and available as a dedicated single-dose pen from April 2026, narrows that gap. Trials reported around 20.7% average weight loss at 7.2mg over 72 weeks. So the landscape shifted meaningfully in early 2026, and anyone comparing these medicines now should factor in that higher semaglutide dose as part of the picture. You can read more on the Wegovy treatment page for the current licensed detail.

The mechanism difference: why two receptors produce a different result

If you want to understand how semaglutide works as a medicine, it mimics GLP-1 (glucagon-like peptide-1), a gut hormone released after eating, slowing the speed at which food leaves the stomach, signalling fullness to the brain and reducing overall appetite. That single-pathway action is well-established; the STEP programme involved thousands of adults and built a consistent safety profile over several years.

Tirzepatide activates both GLP-1 and GIP (glucose-dependent insulinotropic polypeptide) receptors simultaneously. GIP is involved in fat storage and metabolism as well as appetite, and the combination appears to produce a stronger appetite-reducing signal than either pathway alone. This dual action is why NICE and the trial investigators expected the greater weight reduction, and why tirzepatide carries the MHRA's Black Triangle designation, additional post-marketing safety monitoring applies, as it does for Wegovy. For an accessible summary of how these medicines work in the body, the NHS tirzepatide medicines page and the equivalent semaglutide page sit alongside each other in the NHS Medicines A–Z.

What the mechanism difference does not change: both medicines require the same commitment to lifestyle changes, both carry a broadly GI-led side-effect profile (nausea, loose stools, constipation, reduced appetite being the most common), and both are titrated gradually by a prescriber to reduce tolerability problems at the start. A fuller look at the wider class of semaglutide-adjacent medicines covers how orlistat and older GLP-1 agents fit into that picture.

Oral semaglutide: what 'similar to Wegovy' looks like without a needle

On 11 June 2026 the MHRA approved Wegovy tablets, making the UK the first country in Europe to license an oral GLP-1 medicine specifically for weight management. For people asking what is similar to Wegovy but without an injection, this is now a live option rather than a hypothetical one.

The tablet contains semaglutide co-formulated with an absorption enhancer. The dosing schedule runs from 1.5mg daily through 4mg and 9mg to a 25mg maintenance dose, with at least one month at each level. Taking the tablet requires a specific routine: first thing in the morning, on an empty stomach, with a small amount of plain water, and nothing else for at least 30 minutes. No refrigeration is needed, which some people find suits travel or unpredictable schedules better than a pen kept in the fridge.

In the OASIS 4 phase-3 trial (64 weeks, 307 adults), average weight loss was around 13.6% compared with roughly 2.4% on placebo. Among participants who stayed fully adherent throughout, that figure rose to about 17%. These are early data from a single trial, and the oral route is not yet available on the NHS, a NICE appraisal would be required first. If Wegovy costs are part of your thinking, the Wegovy price page sets out what private treatment typically involves. For a side-by-side look at semaglutide in its different licensed forms, the page on Ozempic and Wegovy clarifies which semaglutide products are licensed for weight loss and which are not.

Choosing between them: what the decision actually involves

The practical question most people land on is this: given that tirzepatide generally produces greater average weight loss in trials, is it always the right choice? The honest answer is that it depends on the individual. Eligibility, existing health conditions, previous treatment history, how someone tolerates injections and a range of other factors all feed into a prescriber's assessment.

Some people will not qualify for tirzepatide under the private licence criteria but will for semaglutide, or vice versa. Others will have started on one and be considering whether to switch; that conversation belongs with a prescriber who can review the clinical picture, not a comparison article. Biosimilar versions of semaglutide are also entering the conversation, the biosimilars page covers what is and isn't licensed in the UK right now.

If you have come to this page mid-month wondering whether to start before the end of the week, that's a reasonable place to be. Orders placed before 12pm Monday to Friday are reviewed by a GPhC-registered Independent Prescriber the same day and dispatched that afternoon if clinically suitable, delivered the next working day by DPD, tracked to your door. Our clinical team reviews each consultation personally; the about us page explains how the service is structured. When you're ready, starting a free consultation is the step that turns comparison into a clinical plan.