Weight Loss Injection Options in the UK (October 2026)

01 · Compare

The main weight loss injection options

Three prescription injections make up the licensed choices.

You can read more about options for weight loss medication, including tablets, or our overview of oral and injectable options.

02 · Decide

How to choose between them

The right option depends on your health history, other medicines, how you tolerate side effects and whether you prefer weekly or daily dosing. A prescriber makes that call; no page can rank them for you.

Weekly pens suit most people who dislike daily routines. Our Mounjaro pen starts at a standard £169.99 per month, and a new customer's first order is £40 less with code FIRST40. The Wegovy pen first order starts at £99.99. When you are ready, our weight loss clinic starts with a free consultation reviewed by a GPhC-registered prescriber.

03 · Mounjaro in detail

Mounjaro in detail

Mounjaro is the brand name for tirzepatide, a once-weekly injectable prescription medicine made by Eli Lilly, licensed in the UK for weight management in adults and for type 2 diabetes.¹ It activates two natural gut-hormone receptors at once, which helps regulate appetite and slows how quickly the stomach empties. Most people feel fuller sooner and less hungry between meals.¹

Everyone starts on 2.5mg weekly. After at least four weeks the dose rises to 5mg, then can step up in 2.5mg stages to a maximum of 15mg, depending on response and tolerance.¹ Higher is not automatically better, and many people settle at 5mg, 10mg or 15mg.

04 · What the evidence shows

What the evidence shows

In the SURMOUNT-1 trial of 2,539 adults, people taking tirzepatide alongside diet and exercise lost on average 15% of their body weight on 5mg, 19.5% on 10mg and 20.9% on 15mg over 72 weeks, compared with 3.1% with lifestyle changes alone.² These are trial averages, so individual results vary, and treatment works alongside a reduced-calorie diet and increased physical activity, not instead of them.²

05 · NHS or private?

NHS or private access

Mounjaro is available on the NHS, but access is being phased in over several years. NICE recommends it for adults with a BMI of at least 35 plus at least one weight-related condition, and the primary-care rollout began in June 2025 with the highest-need groups first.⁴⁶ Full rollout is expected to take years, which is why many people who meet the licensed criteria choose regulated private treatment rather than waiting.

NHS access to Wegovy runs through specialist weight-management services; ask your GP.

06 · Options to avoid

Unregulated 'injection' options

Products sold as fat-dissolving, colostrum or vitamin 'weight loss injections' are not the same as licensed GLP medicines. They have no comparable trial evidence behind them, as our guide to colostrum weight loss injections explains. Sellers offering to supply a prescription injection without a consultation or prescription should be avoided, as counterfeit pens are a recognised risk.⁷

Our Mounjaro comes through official LillyDirect supply, as genuine KwikPens. See also the healthiest weight loss injections guide.

07 · Realistic expectations

Realistic expectations

Weight loss on injections is gradual by design. The first weeks on 2.5mg are an adjustment phase and losses are usually modest, with most measurable progress building from 5mg onward. Trials measured results at 72 weeks, so think in months, not days. If you have lost less than 5% of your starting weight after 6 months on the highest dose you can tolerate, your prescriber will discuss whether continuing or stopping is right for you.¹