The top 10 weight loss injections — and what the evidence really says

Step 1: Cut through the noise, which injections are actually licensed here?

Type "top 10 weight loss injections" into any search engine and you'll find a mix of legitimate medicines, unregulated compounds, and products that have never held a UK licence. It's genuinely confusing, and a lot of readers land on this page feeling frustrated by that. So let's be direct.

Two injectable weight-loss medicines are licensed by the MHRA for use in adults in the UK right now. If you want a clear overview before going further, our guide to the top weight loss injections available in the UK covers both options in plain terms. Weight loss injections as a category effectively means these two options for the vast majority of UK adults seeking treatment:

Tirzepatide (Mounjaro), a once-weekly injection made by Eli Lilly. It activates both the GIP and GLP-1 receptors involved in appetite regulation and blood-sugar control, making it the only dual-agonist weight-loss medicine licensed in the UK. The SURMOUNT-1 trial reported an average body-weight reduction of around 20–21% over 72 weeks at the highest dose, among adults without diabetes. NICE's appraisal of tirzepatide (TA1026) recommends it for adults with a BMI of 35 or above alongside at least one weight-related health condition, with lower thresholds for some ethnic backgrounds.

Semaglutide (Wegovy), a once-weekly injection made by Novo Nordisk. It acts on the GLP-1 receptor only. The STEP 1 trial reported an average weight reduction of around 15% over 68 weeks at the standard 2.4mg dose. A higher 7.2mg dose was approved by the MHRA in early 2026, with trial data suggesting approximately 20.7% average loss. NICE's recommendation for semaglutide (TA875) covers adults with a BMI of 35 or above and at least one weight-related comorbidity, within a specialist weight management service, for a maximum of two years.

Any other injectable names you've seen (liraglutide (Saxenda), insulin, compounded peptides) are either licensed for different conditions, not licensed for weight loss at all, or are products the MHRA has warned against. The top-rated weight loss injections by clinical evidence are these two.

Step 2: Understand what separates them, mechanism, results and practical use

Choosing between tirzepatide and semaglutide isn't a decision anyone should make based on a comparison article alone. That said, knowing the differences helps you ask better questions at your consultation.

The dual-receptor mechanism of tirzepatide is the main structural distinction. GIP and GLP-1 together appear to produce stronger appetite suppression and a more pronounced effect on body weight than GLP-1 alone, at least in the trials conducted so far. The SURMOUNT-5 head-to-head trial, published in the New England Journal of Medicine in 2025, found that tirzepatide produced greater average weight reduction than semaglutide 2.4mg over 72 weeks in adults with obesity and no diabetes.

That said, semaglutide at 7.2mg narrows the gap considerably. And individual responses vary. Some people do better on semaglutide; some find tirzepatide's side-effect profile easier to manage. You can read more about the top three weight loss injection options broken down in more detail, or explore the broader treatment landscape if you're still weighing up whether an injection is the right route for you at all.

Practically, both are subcutaneous injections given once a week at home, using a pre-filled pen. Both start at a low dose to help your body adjust, tirzepatide begins at 2.5mg, a starting point designed to minimise nausea before the dose is titrated upward. Both require refrigerated storage. Both are Black Triangle medicines, meaning the MHRA keeps additional watch on them as newer treatments.

For those who prefer to avoid injections entirely, there is now a licensed oral option: the Wegovy tablet. You can find more on weight loss injections in pill form (including how the oral route compares) if that's relevant to your decision.

Step 3: Know the eligibility picture before you book anything

Both medicines are prescription-only. A prescriber decides suitability, not your BMI alone, and certainly not a questionnaire-scoring algorithm.

For private treatment, the licensed criteria are: adults aged 18 or over with a BMI of 30 or above, or a BMI of 27 or above alongside at least one weight-related health condition (such as high blood pressure, type 2 diabetes, high cholesterol, or obstructive sleep apnoea). Lower BMI thresholds apply for some ethnic backgrounds under UK guidance. Meeting those numbers is the starting point. Your full health history, current medicines, and any conditions that might make either treatment unsuitable are assessed before a prescription is considered.

NHS access follows stricter phased criteria tied to NICE's appraisals. As of mid-2026, NHS tirzepatide is available to adults with a BMI of 40 or above alongside four or more qualifying conditions, with eligibility broadening in further cohorts through 2026 and 2027. Wegovy on the NHS is routed through specialist weight management services, where waiting lists are commonly long. If you don't meet current NHS criteria or don't want to wait, a regulated private prescription route is the lawful alternative.

A quick note on verifying any online provider: you can check any UK pharmacy against the GPhC register at pharmacyregulation.org/registers. For what to look for and why it matters, the frequently asked questions on the nume site cover verification and safety in more depth.

Step 4: Get a clinical review that actually considers you

The final step (and really the only step that matters) is a consultation with a registered prescriber. At nume, our clinical team reviews every consultation personally, the same day, before any prescription is issued. A real clinician reads your answers; no automated triage makes the call. If treatment is clinically appropriate, and you order before midday on a working day, your prescription is dispatched that afternoon by tracked DPD for free next-working-day delivery, in plain unbranded packaging.

If you have questions before starting, the support team is available seven days a week. The consultation itself is free, with no obligation to proceed.